Stella 2T highway/performance upgrades
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Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sat Mar 27, 2021 7:16 pm quote
QA I dont think my info is much help to someone, but hopefully you can glean something out of it and get your stuff set up much faster than mine! I made an analogy the other day that I feel like jetting is starting to click in my mind, yet even so.. it all still feels a bit like a blindfolded pinata party even with some basic knowledge. But I do feel like I have at least one variable out of 3 closed to being locked down.. main jet. Then its just a matter of experimenting with the other 2 variables to get everything in line and set up properly. Maybe before this thread is 3 years old I'll finally have it perfectly jetted and can put this obnoxiously long thread to bed! "Go the fuck to sleep" said in Samuel L Jackson voice.

Hibbert, I dont know why it always posts so small even when the image is large that I upload. It is 20.07 HP at 8600 rpm and 19.18 Nm torque at 7100 rpm. Grain of salt with this as I'm still just using low quality audio recordings as I haven't used the multimeter yet to figure out my ranges for Christopher's board setup as it relates to my bike.

I also leave the Cd and the other couple of unknown fields default cause I just don't understand how to set them up properly. I know CM22 has done a lot of effort on these fields, but I glossed over it at the time cause I was dealing with other problems with my build. At some point I need to revisit cm22's work on those obscure fields on the gsf dyno, and hopefully get a dyno board made up to work directly from my rpm cable (which is now working again, albiet the gauge isn't reading the signal properly).
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sat Mar 27, 2021 7:34 pm quote
BTW, I found these links the other night which I think help expand on some ideas Jack has brought up on MV.

Piston wash being a good way to judge finer jetting details:
https://www.screamandfly.com/showthread.php?303619-merc-2-5-piston-wash-pics-rich-or-lean

http://greenhulk.net/forums/showthread.php?t=221865&p=2437229&viewfull=1

and this one talking about using the plug flat ring on the base of the outer sheath to judge idle and air mix. Granted he's talking about different carbs, but you just have to convert the idea to si carb idle jets which is really just swapping them out to find the right mixture as Jack has reminded me many times!
https://sites.google.com/site/kensautomachineshop/technical-information/articles-and-tips/tips---reading-spark-plugs



Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sat Mar 27, 2021 8:22 pm quote
As far as idle richness, I'm currently at 48/140 which is approx 2.90 mixture.
I'm going to try a 40/120 which is about 3.0 mixture and see what the plug color looks like because I think around there would be enough of a leaning out to get it into the right color.. then if that works, I'll drill my 45/140 idle to 46/140 to make it around 3.04 mixture, but with a higher fuel flow rate than the 40/120. That or I can drill my 48/140 to 48/145 which is about 3.02 mixture, and is the same fuel flow rate as my current idle, but slightly leaner mixture.
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Sat Mar 27, 2021 8:43 pm quote
Swiss,
Looks like progress.
Post a screen shot of your setting page from the GSF dyno - and I'll give you my two cents on setup.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sat Mar 27, 2021 9:05 pm quote
Here you go. Left cd and the other obscure fields default.

I changed weight, temp, air pressure, tire and gearing.



Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Mon Mar 29, 2021 5:57 pm quote
Packed up and headed to Florida early am.

Did a little run after swapping to 132 mj and 40/120 idle. It's getting close to correct on both ends but needs work in the middle.

Plenty of time and long straight roads to finish jetting in the next week or so down in Florida. Also no more rain and cold!



Ossessionato
79 P200E, 62 Allstate, 2008 Stella
Joined: 11 Jan 2006
Posts: 2098
Location: Florence, OR
Mon Mar 29, 2021 5:59 pm quote
Safe travels! BTW, thanks for the vid of your area - that was cool!
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Mon Mar 29, 2021 8:37 pm quote
Well - I do love a Vespa in the back of a pickup.
Make sure the tie downs on the handle bars are not on the grips - you dont want to pull on the tubes.

Ok - GSF.
Here is a cheat sheet of sorts.
1. Weight - needs to include the rider. Just sayin.
2. CD & Frontal - ok
3. Gear ratio - is that correct? I used Chandlerman's calculator. Tried to upload but cant - Simple to use. Maybe CM1 can forward to you.

Hope that's helpful.
Enjoy the trip.
Sounds great!

-CM
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Mon Mar 29, 2021 9:01 pm quote
charlieman22 wrote:
Well - I do love a Vespa in the back of a pickup.
Make sure the tie downs on the handle bars are not on the grips - you dont want to pull on the tubes.

Ok - GSF.
Here is a cheat sheet of sorts.
1. Weight - needs to include the rider. Just sayin.
2. CD & Frontal - ok
3. Gear ratio - is that correct? I used Chandlerman's calculator. Tried to upload but cant - Simple to use. Maybe CM1 can forward to you.

Hope that's helpful.
Enjoy the trip.
Sounds great!

-CM
Weight includes rider, bike, weight of gas and approx weight of accessories and items in glove box.

Gear ratio is correct. I calculated it based on my gearing myself and added it to the list of gearing options. That's actually not that hard to do once i read about it. Find the ratio of your input shaft (clutch gear and the biggest ring on the input shaft 22/6, find the ratio for your drive shaft based on what gear you do your run in (2nd gear toothing count and the Christmas tree matching second gear tooth count). Then multiple the two ratios together and bam! Enter it into the field.
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Mon Mar 29, 2021 9:14 pm quote
Quote:
Weight includes rider, bike, weight of gas and approx weight of accessories and items in glove box.
Hahah.
I stand corrected.
Lazy read and I forgot its in Kg - not Lbs.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Thu Apr 08, 2021 3:41 pm quote
No matter what I did, I could not get the 130-70 tubes off the tubeless rims after 3 months trying. So I found a motorcycle shop close to here today that would swap the 130-70 for 110-80 Heidenau K58 tires.

I was hoping to salvage the 130-70 Heidenau K62 for CL or FB Marketplace. The guy destroyed them getting em off the rims. They were that tight that the beads are warped and torn at some spots. Also did a number on the brand new sip tubeless rims. I guess those tubeless rims are real tight for these tires to get on and off. Love em, but probably will get split tubeless rims next time cause its such a pain to swap tires on them.

The new 110-80 tires are also quite a tight fit for getting the rear tire on and off. Definitely need to install it fully deflated and remove the exhaust plus jack up the back of the scooter high enough to make room.

The 110-80 K58's are much meatier than the old sip performer 2.0 tires. Looks like they will be better for grip and hopefully longer lasting.


K58 110-80


Brand new rims beat up!

Ossessionato
79 P200E, 62 Allstate, 2008 Stella
Joined: 11 Jan 2006
Posts: 2098
Location: Florence, OR
Thu Apr 08, 2021 5:27 pm quote
Sweet tires, but holy crap, a professional shop butchered the rim? Ouch...

Oh well, it's only a rim....
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Thu Apr 08, 2021 5:29 pm quote
You should see the brand new 110-70 tires they took off! I was like oh well i guess that was wasted money as i won't be able to resell those!
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Thu Apr 08, 2021 8:44 pm quote
Tires look pretty narly.
Is that still a word?

How do they ride?
Noise/smooth?

Gotta imagine that's a great choice for NY roads.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Fri Apr 09, 2021 11:23 am quote
Well the new wider chunkier tires are more solid and planted. Especially over bumps. Seems much sturdier on the road, although the turning is slightly less nimble due to fatter tires.

The rear one has just enough clearance for the clutch cover. It was also a pain in the ass to put the rear tire on. I need to keep the exhaust on (tried with it off and couldn't get the exhaust bolt back in with the wide tire on) and lay it on the engine side in the grass. Then I can get the wide tire on and off with minimal problems. But doing it jacked up on center stand there just isn't enough room to get the wide tire in and on.

Also my 3/8 plug chop looks good, but I feel like my idle or mix screw is too rich cause it runs great for miles, but as soon as I stop at a store and come back out 10-15 min later it has trouble starting. Or if I sit at a red light for too long it feels like its fouling the plug. So my guess is the idle is still a bit rich.


120/be3/130 3/8 throttle plug


120/be3/130 3/8 throttle plug


just enough space between wide tire and clutch cover 110-80 tires.


this was my failed attempt to get the wide tire on with exhaust off.




I think the idle is too rich causing this extra clean wash and hard starting.





Jet Eye Master
PX221 MHR, O tuned PX200, PX125 and some motorbikes
Joined: 14 Jun 2017
Posts: 2755
Location: London UK
Sat Apr 10, 2021 2:05 pm quote
swiss1939 wrote:
Also my 3/8 plug chop looks good, but I feel like my idle or mix screw is too rich cause it runs great for miles, but as soon as I stop at a store and come back out 10-15 min later it has trouble starting. Or if I sit at a red light for too long it feels like its fouling the plug. So my guess is the idle is still a bit rich.
Not necessarily, this can go either way. Poor hot starting is most often due to being too lean. An idle that slows and bogs over time can be either. Just plain too rich as described or contraveritially, in some situations, too lean. When too lean the slide is closed too far causing the engine to slowly over cool and bog. Easier to open the mix screw a bit and then tickover up to check lean, before reducing pilot jet size.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Tue Apr 13, 2021 7:07 am quote
Yes easy test which I did. Idle was 52/140 1.5 turns mixture. Went to 2.5 turns mixture and let it idle on stand for 5 min. Fouled plug and died within 5 min. Pulled plug and drenched in fuel/oil. Too rich. Switched to 55/160 idle as I've already tried the similar 48/140 idle before. Figured it was worth a shot to try similar idle but with slightly more fuel flow 55. New 55/160 idle at 2 turns mixture screw and it doesn't foul plugs after 10 min idling on stand. Then taking it for a ride around the block to warm it up and let it idle on stand for another 10 min no dying. Turn it off and come back to it 10 min later and it starts right up. Probably still slightly rich idle as pulling the plug shows a half wet plug and fully black ceramic/flat circle. So I think a 48/140 at 2 turns or a 45/140 at 2.5-3 turns is probably my target idle. I'll ride around for a few days on the 55/160 first to see how its changed on typical rides from the previous idle.

I also went back to a 132 main jet as the 130 I just felt it was a little too quick to get to upper temp targets and would be a little too on the edge on a long full WOT highway ride in this Florida heat.
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1683
Location: Rochester, Minnesota
Tue Apr 13, 2021 8:59 am quote
swiss1939 wrote:
Yes easy test which I did. Idle was 52/140 1.5 turns mixture. Went to 2.5 turns mixture and let it idle on stand for 5 min. Fouled plug and died within 5 min. Pulled plug and drenched in fuel/oil. Too rich. Switched to 55/160 idle as I've already tried the similar 48/140 idle before. Figured it was worth a shot to try similar idle but with slightly more fuel flow 55. New 55/160 idle at 2 turns mixture screw and it doesn't foul plugs after 10 min idling on stand. Then taking it for a ride around the block to warm it up and let it idle on stand for another 10 min no dying. Turn it off and come back to it 10 min later and it starts right up. Probably still slightly rich idle as pulling the plug shows a half wet plug and fully black ceramic/flat circle. So I think a 48/140 at 2 turns or a 45/140 at 2.5-3 turns is probably my target idle. I'll ride around for a few days on the 55/160 first to see how its changed on typical rides from the previous idle.

I also went back to a 132 main jet as the 130 I just felt it was a little too quick to get to upper temp targets and would be a little too on the edge on a long full WOT highway ride in this Florida heat.
A little rich doesn't leave you walking home with a melted piston.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Tue Apr 13, 2021 11:04 am quote
I will not be riding the edge on idle jet leanness. I am still rich enough to go down safely one more with opening up of the mixture screw. I have tested it a few times and I can see that the temps get more erratic when I go to lean on the idle. So I will find the nice safe spot for temps and plug color which will most likely be one small idle size down from now with mixture screw opening slightly. The further jump would be riding the lightning which I prefer not to do. I've had enough seizes on this setup to be cautious.

Unrelated to jetting.. I've gotten end of life out of the horncast that came on this stella. The plastic tabs that hold the screw clips on for the bottom two screws have broken off multiple times. Also the top center screw hole behind the badge has broken off multiple times. I've reglued them back on a few times now but they have broken off for the last time. Those pieces have fallen out on the road somewhere no longer found. So I am finally replacing my horncast with one of the multiple spares I've picked up over the years from scooter purchases.

This time, I've decided to try an experiment. I bought a fiberglass repair kit from autozone and I've applied some fiberglass backing to the screw mounting points on the plastic horncast to hopefully provide some reinforcement and prevent and future breakage. This is because my wiring under the horncast is so packed there really isn't enough space for it all and when I tighten down the screws to remove any gap.. the plastic starts bending and breaking from the pressure of all the wiring below.

My hope is the fiberglass backing in critical points keeps the horncast from breaking when tightening down. I've also applied a strip along the side walls down the sides of the horncast as that has cracked on my old one as well. Its an experiment as I've got a few of these spare horncasts in case this one fails miserably.

I've also got to find a close matching can of spray so this doesn't stick out like a sore thumb. If not, then its going black.


broken tab on left. center top screw plastic also broke a few times and reglued.


fiberglass patches to help add strength.









Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Wed Apr 14, 2021 1:09 pm quote
New horncast on with fiberglass reinforced backing. Spray can doesn't quite match but its as close as I could find at hardware store. Its not far off, but just slightly brighter. If anyone is trying to find a close match for 2005 stella red, Rustoleum semi gloss Sunrise Red.

Also got the tachometer rewired to the blue wire coming from stator plate instead of the red wire to the ht coil. This seems to have solved my tach problems. I did buy the koso filter which all it does is remove the jitter in the reading, doesn't fix the previous inaccuracy problem I had. It was exponentially off starting about 1.5x the correct reading, but under throttle it would be like 3x inaccurate at full throttle. So where my cheap tach was reading 1200 at idle, the koso was reading 1800, but under throttle the cheap tach was reading 5000 while the koso was reading 15000. This was when I was connected to the red wire for ht coil from stator. Blue wire solved everything, albiet I had to change my koso tachometer settings drastically with the sip variable ignition compared to the original LML ignition. Now the koso gauge is set to 4 stroke engine with 12 pistons for it to read correctly.

Other than that, I got out on the stella this morning and rolling away from the hosue the front end was wobbly and strange. Turned out my front tire was flat. So I'm thinking that motorcycle shop I took the tires to for mounting really did a number on my brand new tubeless rims. Either the rims or the tires he put on were f'ed up and now the front tire loses air in like 5 days. I filled it up again and am gonna keep checking it to see if it was just a fluke or if its a problem. These sip tubeless rims are great but a real pain in the ass to change tires on. I'm regretting the purchase and wishing I went for the pinasco tubeless split rims.






new left, old right.



Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Wed Apr 14, 2021 6:36 pm quote
Swiss - lookin good!
Know you have an eye - so here is a head's up.
There is an auto paint supply store within driving distance of you that will make a custom color for you - in a spray can.

Call around - you will find them - and bring them a panel.
Cost - $20.
Bring them a waxed panel - so its as good as it gets - and they will match and put it in a can for you.

That said - it looks pretty damn good as is - nice repair.
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1291
Location: California
Wed Apr 14, 2021 6:55 pm quote
looking good swiss like the genuine badge got one for the top?
Ossessionato
76 Sprint V, 63 GL, 62 VBB, 05 Stella
Joined: 16 Jun 2011
Posts: 3201
Location: Nashville
Thu Apr 15, 2021 12:26 pm quote
I think scooterworks still sells the Genuine badges, or they did at one time.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Thu Apr 15, 2021 12:37 pm quote
I have one but i forgot it in my garage up in nyc so I'm just gonna leave it as is until i get back up there. No sense in buying another one. I can deal with it missing for a few months.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sat May 01, 2021 3:54 pm quote
Been a while since updated but I've been doing a lot of tweaking on this one in spare time. I skimmed the head down after finally doing a physical check instead of trusting the measurements before install. My squish is uneven due to fixing the head damage from a previous seize. My measured squish with solder was something like 1.31mm near the spark plug and 1.15mm on the opposite side bottom of head. Figured it was about 1.25mm squish on average. So i skimmed it down on 150 grit over glad. Took about 30-40 min with constant measurements. Not as bad as you think to do it by hand. Now it's measured by solder as something like 0.9mm on top side and 0.79mm on bottom side which worked out to about 0.81mm average squish. The spread of top to bottom squish ended up much closer after the skim.

After doing that, it runs so much better but i had to go up a bit on jetting. I've been able to go up to 140mj and it runs great at wot but is a bit stuttery rich getting up to it. Also went way richer idle to the included idle jet that came with the kit. 52/140. It runs rich but temps are safe 90% of the time.

I took it on a 65 mile ride up route 1 Florida to my sister's house. It handles the 65 miles most of it going 45-65mph. Definitely need to walk the main jet down slightly as it bogs mid range until it revs up to 6000 and i can't stay in 4th unless I'm over 6000rpms due to that bog. But holding wot in 4th at about 7500 it was pretty stable at about 300-320f for long time. Temps only climb if it bogs.

Walking it back to 138 mj for my return trip tomorrow but i think I'll still be rich and end up at 135. I'm also looking to experiment with a 26/26 carb because I'm already at such a large main jet.

This thing seriously sounds and feels like a much bigger motorcycle than what it looks like!
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Sat May 01, 2021 10:20 pm quote
Sounds fun - love that you've gotten a handle on the jetting.
Big ride like that is awesome - and gives different more distinct perspective on tuning - helping you nail that last 10%.

Of course - when you get it perfect - after all the time finessing it - you do something like move to a 26/26 carb... its just the nature of the beast.

🙂
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1683
Location: Rochester, Minnesota
Sun May 02, 2021 3:56 am quote
swiss1939 wrote:
Been a while since updated but I've been doing a lot of tweaking on this one in spare time. I skimmed the head down after finally doing a physical check instead of trusting the measurements before install. My squish is uneven due to fixing the head damage from a previous seize. My measured squish with solder was something like 1.31mm near the spark plug and 1.15mm on the opposite side bottom of head. Figured it was about 1.25mm squish on average. So i skimmed it down on 150 grit over glad. Took about 30-40 min with constant measurements. Not as bad as you think to do it by hand. Now it's measured by solder as something like 0.9mm on top side and 0.79mm on bottom side which worked out to about 0.81mm average squish. The spread of top to bottom squish ended up much closer after the skim.

After doing that, it runs so much better but i had to go up a bit on jetting. I've been able to go up to 140mj and it runs great at wot but is a bit stuttery rich getting up to it. Also went way richer idle to the included idle jet that came with the kit. 52/140. It runs rich but temps are safe 90% of the time.

I took it on a 65 mile ride up route 1 Florida to my sister's house. It handles the 65 miles most of it going 45-65mph. Definitely need to walk the main jet down slightly as it bogs mid range until it revs up to 6000 and i can't stay in 4th unless I'm over 6000rpms due to that bog. But holding wot in 4th at about 7500 it was pretty stable at about 300-320f for long time. Temps only climb if it bogs.

Walking it back to 138 mj for my return trip tomorrow but i think I'll still be rich and end up at 135. I'm also looking to experiment with a 26/26 carb because I'm already at such a large main jet.

This thing seriously sounds and feels like a much bigger motorcycle than what it looks like!
You'll find out today, I'm curious if the bogging at less than WOT is the 52/140 or the main jet. With your WOT temperature being good and not really wanting it to go any higher temps, won't a smaller main raise WOT temps?

What are you running for an Air Corrector? Can you go down a size to reduce main jet size? I went to a 140 or 120 to keep my main jet size something I had in my kit of spares.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sun May 02, 2021 5:50 am quote
Yes I'm with you going down main is increasing temps but i believe my temps were also stable at 138 mj but i went up to 140 to see if it would bog at wot. It doesn't bog at wot, only a little at 5-6k rpm. So I'm experimenting with both the main and idle to figure out where the balance needs to be. Before my 65 mile trip i had experimented on shorter rides with smaller idles. It was all similar but I felt the idle hung just slightly with the smaller idle jet. It would drop quick on idle but hang around 15-1600 then drop back to 1200. I know the current idle is a little rich but it's the suggested idle and I'm willing to accept it slightly rich for safety. Plus i still get good acceleration from stop.

I'm doing the dance on longer trips with changes to the main and idle independently now to figure out which change works best. It's like cm22 said, longer rides are a bit more revealing than even half hour rides in local traffic. I was able to see more specific temp responses to various throttle actions that were being held longer and harder, pushing the jetting to it's limits. One constant i know is the previous target main before the head skim, 132 mj, is too lean. Now it's just a matter of deciding if 135 or 138 is to lean, then bringing the idle into place.

I also still have a small doubt that the mj is not the rich mid range problem but could go up a bit as holding it at wot in high rpms is constant but closer to 325 than 300f than i would prefer. But this is where Jack says it's probably a rich main's unspent fuel causing temps to get hotter due to increased compression. So this is why I'm going to 138 on my return trip today. If it looks better then I'll try 135 on another long trip. I think 138 will be the end result though.

As far as air corrector, Jack has suggested i make a custom air corrector to bring the mj down and get a little more room to play with the mj. So I'm going to try his suggestion this week... Solder up an air corrector and re drill the hole to 1.1mm and use a custom 110 ac. He's saying if i do this then my 138/140 mj will be back down around a 128/130 again. Or to buy a 100 ac, but i can't seem to find any sold in us based stores without having to place an international order through them.

Long story short, I'm real close on getting it locked in perfectly in regards to temps at wot in 4th for days. Just a matter of tweaking it on both ends to get it perfect, all while I'm still trying to keep both ends on the slightly richer end of the spectrum.

Cm22, yeah its funny how this works.. Spend months to a year dialing in the carb and right when you get it perfect, switch to a larger carb! But i figure I'm at the upper limit of what the 24 carb can do well, so going to the next up auto lube carb will hopefully give the engine a better supply with some "breathing room" and a byproduct of that is better temp management and better throttle response throughout.
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1683
Location: Rochester, Minnesota
Sun May 02, 2021 6:04 am quote
swiss1939 wrote:
Yes I'm with you going down main is increasing temps but i believe my temps were also stable at 138 mj but i went up to 140 to see if it would bog at wot. It doesn't bog at wot, only a little at 5-6k rpm. So I'm experimenting with both the main and idle to figure out where the balance needs to be. Before my 65 mile trip i had experimented on shorter rides with smaller idles. It was all similar but I felt the idle hung just slightly with the smaller idle jet. It would drop quick on idle but hang around 15-1600 then drop back to 1200. I know the current idle is a little rich but it's the suggested idle and I'm willing to accept it slightly rich for safety. Plus i still get good acceleration from stop.

I'm doing the dance on longer trips with changes to the main and idle independently now to figure out which change works best. It's like cm22 said, longer rides are a bit more revealing than even half hour rides in local traffic. I was able to see more specific temp responses to various throttle actions that were being held longer and harder, pushing the jetting to it's limits. One constant i know is the previous target main before the head skim, 132 mj, is too lean. Now it's just a matter of deciding if 135 or 138 is to lean, then bringing the idle into place.

I also still have a small doubt that the mj is not the rich mid range problem but could go up a bit as holding it at wot in high rpms is constant but closer to 325 than 300f than i would prefer. But this is where Jack says it's probably a rich main's unspent fuel causing temps to get hotter due to increased compression. So this is why I'm going to 138 on my return trip today. If it looks better then I'll try 135 on another long trip. I think 138 will be the end result though.

As far as air corrector, Jack has suggested i make a custom air corrector to bring the mj down and get a little more room to play with the mj. So I'm going to try his suggestion this week... Solder up an air corrector and re drill the hole to 1.1mm and use a custom 110 ac. He's saying if i do this then my 138/140 mj will be back down around a 128/130 again. Or to buy a 100 ac, but i can't seem to find any sold in us based stores without having to place an international order through them.

Long story short, I'm real close on getting it locked in perfectly in regards to temps at wot in 4th for days. Just a matter of tweaking it on both ends to get it perfect, all while I'm still trying to keep both ends on the slightly richer end of the spectrum.

Cm22, yeah its funny how this works.. Spend months to a year dialing in the carb and right when you get it perfect, switch to a larger carb! But i figure I'm at the upper limit of what the 24 carb can do well, so going to the next up auto lube carb will hopefully give the engine a better supply with some "breathing room" and a byproduct of that is better temp management and better throttle response throughout.
I custom drilled idle jets as I got tired of ordering them. Bought 10, I knew were undersized and drilled the gas size incrementally until I had what I wanted. Soldering one up isn't hard to do.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sun May 02, 2021 6:14 am quote
Yeah I've drilled a custom idle and have plans to do it again as i feel my idle is slightly rich at the current 52/140 (2.69) but slightly lean at both 55/160 and 48/140 which are effectively the same 2.9. similarly bought another super lean idle with the intention to drill out something to fit in the middle. Off the top of my head i think i was planning on drilling the leanest 140 idle jet to 50/140 so i would have one approximately 2.75 mixture.
Molto Verboso
One or two fun scoots....nothing too precious
Joined: 17 Jul 2013
Posts: 1678
Location: UK (South East)
Sun May 02, 2021 10:28 am quote
If you're feeling the need and are happy to buy from the UK:

https://www.kmtproducts.co.uk/?cat=DELLORTO-TYPE-JETS&subcat=D22-Air-Correction-Jet--Dellorto-Type-5827-&page_id=62&menu_id=&category_id=1&sub_category_id=14

Very good and accurate jets in my experience.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sun May 02, 2021 10:41 am quote
swa45 wrote:
If you're feeling the need and are happy to buy from the UK:

https://www.kmtproducts.co.uk/?cat=DELLORTO-TYPE-JETS&subcat=D22-Air-Correction-Jet--Dellorto-Type-5827-&page_id=62&menu_id=&category_id=1&sub_category_id=14

Very good and accurate jets in my experience.
I would if i had more to buy. I'm sure the shipping for one $4 jet across the pond right now is insane!

Update: made the 65 mile trip back today. Started on 138 mj. Temps got a little hotter especially full throttle but were still holding steady at half throttle so i swapped in the 135 and temps were not stable at all. So i went back to the 140 mj and switched to a be1 atomizer. It ran better and temps more stable up to 3/4 throttle but still seemed like it could go over the edge given the wrong throttle and rpms for long enough.

I honestly think I'm rich on idle and lean on main just slightly. Temps are noticeably more stable at 140 than anything below. So before i drill a new smaller ac, I'm going to try 142 and 145 mj and slightly smaller idle and see if i can get the temps to hold stable across throttle and rpms. My thought is a 142 mj will be good, and a 55/160 idle. Mid throttle I'm going to have to experiment with atomizers to find the one that works the best. I think the mid range is being screwed up by the 4.0 slide in the carb. Need to get my hands on a flat bottom slide.

Regarding plugs, i think they are misleading me because the mid range is rich up to 3/4 throttle and the main is slightly lean by a few points at wot. So if i hold 1/2-3/4 throttle temps are stable because the rich idle and lean main even out perfectly at that point, but everything below is rich and tainting the plug color darker.


138 mj 52/140 idle at 3/4 throttle for a few miles


138 mj

Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sun May 02, 2021 11:43 am quote
Holy crap! Just threw 145mj in and went down to 48/140 (2.91) idle in to test my theory that main is lean and idle is rich and went around the block to fill up the tank. This thing took off like a banshee outta hell! It rides like a widowmaker now! Im incredulous that it can handle a 145 mj. Its not perfect, but temps are way cooler and more stable on that short ride. Sub 300F now.. closer to 250F at mid throttle. It needs some tweaking to the idle, atomizer or slide as it revs all the way up to wot super fast and clean, but coming down from wot to mid rpms and holding mid rpms it stutters again. But its quite an improvement! I'm gonna sit on this one for a while and see if I can clean up the mid throttle and check the plug on a really hard run again. It has so much more grunt just from going from 140 to 145 and down 1 idle size.
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1683
Location: Rochester, Minnesota
Sun May 02, 2021 12:47 pm quote
swiss1939 wrote:
Holy crap! Just threw 145mj in and went down to 48/140 (2.91) idle in to test my theory that main is lean and idle is rich and went around the block to fill up the tank. This thing took off like a banshee outta hell! It rides like a widowmaker now! Im incredulous that it can handle a 145 mj. Its not perfect, but temps are way cooler and more stable on that short ride. Sub 300F now.. closer to 250F at mid throttle. It needs some tweaking to the idle, atomizer or slide as it revs all the way up to wot super fast and clean, but coming down from wot to mid rpms and holding mid rpms it stutters again. But its quite an improvement! I'm gonna sit on this one for a while and see if I can clean up the mid throttle and check the plug on a really hard run again. It has so much more grunt just from going from 140 to 145 and down 1 idle size.
Have you measured that Air Corrector ? I wonder if it is drilled wrong?
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Sun May 02, 2021 3:39 pm quote
I have not measured it. I've got some spare larger air correctors I'm gonna solder up and drill one to 110 and think it will drop my main down from 145 to 130.

Curious if anyone knows more about si g carbs vs e carbs? I know the g carb is shorter meant for t5 with larger air filter. I'm curious if they are functionality the same and interchangeable in terms of performance? I kinda want to try a g carb because it is shorter and will be easier to remove screws and fuel line, etc. Possibly the shorter carb also provides more volume inside the carb box for atomized fuel and air.. which maybe helps air flow and acts like a larger carb?

Also wondering if the only jets different on g carbs are the air correctors? Seems like they are shorter air correctors with matching shorter threads? Is it required to use the air correctors meant for T5 carbs or can you use the larger air correctors meant for e carbs as well?


Shorter g carb appealing to me for access and removal reasons.


G carb air correctors shorter than the standard air correctors


Standard.. work on g carbs?

Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Wed May 05, 2021 6:00 am quote
Pushed it to the limit on 142mj. Too lean. 145 is good for uphill in 4th at wot with strong head winds over a bridge. When i did the same thing on 142 it got a little hairy felt like it wanted to lock up and exhaust temps were climbing fast.

So i know my jetting is real close when on real big main jets that are too large for the carb to work properly. So now I'm onto the custom air corrector as Jack suggested. Ordered and received a 1.1mm and 1.0mm bit from mcmaster. The 1.1mm bit measured at 1.08mm on caliper. Soldered up my large 190 ac as I'm never going to use that one otherwise. Drilled a new hole with the 1.08mm bit by hand. I'm now at precisely 108 air corrector.

And to match my previous 120/be1/145 stack which worked out to 0.827.. i needed to be on 108/be1/126.6.. so i went to 128mj (0.843) and hopefully it's dead on or just slightly rich but perfectly usable. So now I will go take for a ride today to see how the temps do with punishment. And can hopefully finally move on to cleaning up the mid range stutter.

Current stack 108/be1/128 and 48/140 idle.





Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Wed May 05, 2021 8:31 am quote
Two words.. HOLY CRAP!

one simple change.. and its as close to perfect as its ever been! This thing is super clean across the whole throttle range. Not a hint of stuttering anymore! Sounds and pulls like a tractor on steroids! Temps are 98% perfect and will get to 100% perfect with minor tweaking.

What a difference going to 108 air corrector has made! Its insane that keeping the same fuel/air ratio but simply reducing the air intake and fuel output has made it go from stuttery and dirty everywhere to perfect!

Over a year of jetting this carb and the end is in sight. Huge weight lifted off my shoulders finally as this jetting not being correct has been a major stress point for me as I'm constantly avoiding riding this thing as much and as long as I would want to out of fear of destroying it yet again due to carb not being set up correctly.

Man, I'm going to put tons of miles on this thing now!

Ossessionato
79 P200E, 62 Allstate, 2008 Stella
Joined: 11 Jan 2006
Posts: 2098
Location: Florence, OR
Wed May 05, 2021 9:41 am quote
I'm glad to hear this Swiss! That's awesome.

Could you give me a rundown on what you're running? It's been a while and I cannot recall. Stroke, bore, carb size, etc. Curiosity has got me going....
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2988
Location: Staten Island, NY
Wed May 05, 2021 10:09 am quote
qascooter wrote:
I'm glad to hear this Swiss! That's awesome.

Could you give me a rundown on what you're running? It's been a while and I cannot recall. Stroke, bore, carb size, etc. Curiosity has got me going....
Sure:

- Malossi 166 MK III kit.

-185/125 timing

-30 degrees blowdown

- 0.8mm squish approximately

-exhaust port widened to something like 68%, reprofiled for more torque.

-1st oversize bore and transfer ports smoothed and widened by Gickspeed

- 60mm long stroke crank (believe I actually measured it to precisely 59.88mm stroke.

- SIP Vape Variable DC Ignition

- Currently set to 17 degrees @ 6000 rpm (going to try to adjust it to 17@8000).

- SIP Road XL exhaust

- SI 24/24 carb with float passage drilled to 2.28mm and an extra float gasket to raise the float another 0.3mm +/-

- 108/be1/128 Main Stack (going to try 132 mj with be3 and see if it runs cooler at wot as I am trying to target 300F max instead of 325F currently).

- 48/140 Idle with 2 full turns out mix screw (might try 2.5 screw out instead.. or might switch to 55/160 (same air fuel ratio) to see if that brings the temps down just that extra teeny bit more).

- BR9ES plug

- 93 Octane gas

- max rpm I believe is currently around 9500-10,000 (cant tell for sure as my tach is acting up again, anytime I get over 7000 rpm, the gauge starts jumping to 10-12k rpms which I know is inaccurate).

- On GPS, can reach 40-50mph in 2nd gear, 65mph in 3rd gear and most i've gotten it to in 4th was 73mph but that was on different jetting. Gonna have to see about top speed in 4th at some point soon.

Just imagine this playing in my head when its running good and fast

definitely in this mass of bodies somewhere (same feeling riding this)


Last edited by swiss1939 on Wed May 05, 2021 2:07 pm; edited 1 time in total
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2241
Location: california
Wed May 05, 2021 12:56 pm quote
Judging by the video- you need to turn your screw out a couple turns. It seems a bit tight.
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