Is this plug OK? DR177 setup.
Post Reply    Forum -> Not-So-Modern
Author Message
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Sun Apr 04, 2021 4:04 am quote
Had annoying low throttle bog in 3rd and 4th gear on px125 with DR177 (bolt on) no port work. 24mm SI with 50-120 pilot, 190, BE4, 116 main, B7HS plug. ignition reduced by 2 degrees.

I have Drilled air filter and SIP road 2.0.

So, plug was indicating rich. So ive adjusted pilot mixture slightly, quarter turn in to lean up a bit and reduced main jet to 115. Im getting the following plug results following several chops
5 mile run at 30mph, ignition off, clutch in inspect. Then another 5mile run at around 45, chop.
A 2 mile run at 60mph ish, chop and 3/4 throttle.
Then a WOT on short stretch roads, 60mph +

The bogging gurgle at low speeds is much improved, tiny bit there but just seeking your advice as to colour of plug. The central porcelain is a sandy brown and the strap itself greyish. The outer part still looks black above the thread. The charts ive looked at say its normal colour but is not the illusive chocolate brown so much spoken of. Ive shone a torch through the cylinder head plug hole and it looks clean inside. Your opinions would be most welcome. Thanks

plug.jpg

Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2907
Location: Staten Island, NY
Sun Apr 04, 2021 5:04 am quote
Plug looks lean to me, white and black strap is hot. And that's a 190ac 119 main? That's really lean. Pnp malossi 177 uses somewhere around 140ac 122 main. Can't see a dr being that drastically different.

Seems like your idle is slightly rich to compensate for the lean main.
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2202
Location: california
Sun Apr 04, 2021 6:58 am quote
Swisss almost certainly has it right.

Ferris - you are well outside the expected range - far too lean - with your jetting.
Careful - you are in seize territory with your current jetting

I would swap to a 120, 140, or even 160 Air corrector - which will both make it richer and bring you to a norm that others use so you can get some references.
Your 116 MJ should be paired closer to a 120 or 140 air corrector - that's how far out you are right now.

The std way to jet it in, is to put such a big main jet in that the motor just wont rev out, or splutters when you try and run wide open throttle.
Then walk your way down to the right jet from there.
This is the safer manner to get yourself in to the right range.
If you start lean - as you are - you may seize your motor before you get to a rich enough setting.

Finally - your plug shows an average of all throttle positions. You are likely way lean at full throttle (main jet) and a bit rich at low throttle (idle)
Concentrate on the main first.

Once you get closer, you can do some WOT runs that will give your plug a color you can reed.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Sun Apr 04, 2021 10:26 am quote
Thank you for your helpful info. The scooter was setup not by myself, its going back to them next weekend. But in the meantime, i have found a 140 air corrector on a 20mm SI carb which I can use with the 24mm SI. I have the following jets to hand 120, 118, 116, 115, 114 and a 113. To keep it running until next weekend, is it ok for me to put the BE4 with the 140AC and try these jets? I presume the 50-120 pilot jet is ok for now? That plug by the way, although the porcelain looks white in photo it is actually light brown.
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2202
Location: california
Sun Apr 04, 2021 10:47 am quote
Hard to know for certain - but at minimum put in the 140 and the 120 mj. If you are lucky - it will be too rich to rev out - though - I suspect not.
Don't run hard WOT until your in a position to start rich and move lean as suggested.
Not sure who set it up - but perhaps better for you to take it on?

Consider this: no vespa came from the factory with as lean a setting or with a 190 AC, not even P200's - so I am not sure why anyone would try and jet an SI with that. The main float bowl hole can not pass enough fuel through it to cover that kind of AC without it being drilled unreasonably large.

Gray colors on your plug are bad. Mean dangerously lean.
Jets are inexpensive - so grabbing a few larger wound't hurt.
That float bowl hole I mentioned will struggle to feed more than about a 118/120 jet.
That means if you put a 130 in - it will still only behave like a 120.
The advantage of the smaller AC in your case will be to give your carb a broader range of tuneability - meaning up to perhaps a high 120's MJ can be fed without drilling out the hole.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Sun Apr 04, 2021 11:48 am quote
Thanks for this info. In curiosity when do you start heading towards changing atomiser ? So assume I put in 118 and itís too rich, say, would it be case of dropping down jet or changing the corrector or the atomiser up , so be4 to be5 ? Or is it best to work with the corrector over the atomiser ?
Ossessionato
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 2202
Location: california
Sun Apr 04, 2021 12:58 pm quote
BE4 should work - BE3 would also be fairly neutral as well.
For time being - lock in your atomizer and AC where you are.
See if you can make it too rich - wont rev out/splutters/ splooge out exhaust around cylinder connection.
Then start to walk it down.
That's the process.
Once you get the main - you can turn your attention to the idle.
Not so hard really.
Good luck.
-CM
Hooked
2005 Stella 2T
Joined: 14 Jun 2020
Posts: 119
Location: MA
Sun Apr 04, 2021 1:01 pm quote
That is some funky jetting.

One thing that stands out to me is the BE4 mixer. That is rather rich and I wonder if that crazy-ass AC190 wasnít a misguided attempt to compensate. For the short term, definitely use the AC140, but donít be surprised if that takes you from too lean to too rich. For the longer term, you might want to go slightly leaner by pairing the AC140 with a BE5 and then adjust the main jet to suit.

That 50/120 idle jet is richer than usual too. Makes you wonder if someone wasnít trying to compensate for an air leak.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Mon Apr 05, 2021 5:54 am quote
Thank you all. I happen to have the ac140 and a be5 still in the old 20mm card and got jets from 120 down to 115 so will have a go tomorrow.. will start with the ac140 and be4 plus 120. What do you estimate as being smallest jet to use? On the subject of the pilot jet what would you recommend once my top end indicates correct plug colour. I have 50 - 120 in it ar moment. But have a 45-140 to hand... my carb is 24mm
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2907
Location: Staten Island, NY
Mon Apr 05, 2021 6:20 am quote
55/160, 52/140? Somewhere around there. 55/160 is stock for p200. pnp dr177 is probably close to that.

Think of it this way. stock p200 55/160 idle. 160 (air) divided by 55 (fuel) = 2.9 (air fuel mix). Current idle on a pnp dr177 50/120 = 2.4 (a/f mix). Thats a bit richer than a p200 stock idle (smaller the number.. more fuel.. higher the number more air). Probably not necessary. Try the 55/160. If it feels lean.. a 52/140 is slightly richer (2.69). If it feels rich, try 40/120 (3.0).

Scooterlounge says a stock p125x with 20/20 carb has a 48/160 idle (3.33). So you know you want to be richer than that.. and probably at or just a bit leaner than stock p200 (2.9).
Hooked
2005 Stella 2T
Joined: 14 Jun 2020
Posts: 119
Location: MA
Mon Apr 05, 2021 8:10 am quote
ferriswolf wrote:
Thank you all. I happen to have the ac140 and a be5 still in the old 20mm card and got jets from 120 down to 115 so will have a go tomorrow.. will start with the ac140 and be4 plus 120. What do you estimate as being smallest jet to use? On the subject of the pilot jet what would you recommend once my top end indicates correct plug colour. I have 50 - 120 in it ar moment. But have a 45-140 to hand... my carb is 24mm
I would make it an early priority to figure out whether you really need that BE4 mixer tube. That is the richest mixer offered. Some kits need it, but I do not recall ever hearing that the DR 177 is one of those. The BE5 plays well with an AC140 air tube and will put you closer to the norm when it comes to sizing the main jet. Since you already have a BE5 at hand, I would start with an AC140/BE5/MJ120 main stack and see what you get. If there is no lean bog at mid-throttle, you donít need the BE4.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Mon Apr 05, 2021 9:25 am quote
Swiss and kawalski thx so much for all your time with this. Really appreciate it. So I will stick with tuning with the road 2 exhaust as have plans to put polinibox on when everything stable. Don't want to complicate things at moment. So I won't bother dealing with pilot jet yet until main is happy. I will try the be5 and ac140. Cheers guys
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Tue Apr 06, 2021 7:09 am quote
So i couldnt find my 120 MJ so ive done two tests until the 120 turns up.

AC140 BE5 and 118 MJ - Did not bog out out or splutter. Scooter revved out through each gear, sounded smooth and not strangled.

AC140 BE4 and 118MJ - Exactly the same as the above accept it smoked a tiny bit on startup, but sounded smooth, possibly smoother than the above.

It was so cold out that i wasnt able to run a significant distance to impact on a new B7HS spark plug. However, both of the above gave me that tone on the scooter that sounded as if it was happy. Previously with the AC190 BE4 and 116, i can only explain the sound at high speed as if it was screaming its nuts off but like it was a dry strangled sound.

So when the 120 MJ turns up, i will try the same again with BE4 and BE5.

Charlieman22 mentioned that the 24mm SI wont be able to take advantage of a jet over 120, so if i put the 120 in and find that i still rev out, what is my next step? From this info a larger jet wont work for this tuning will it? Am i looking to rich up by going to a BE3 mixer, then see if i cant rev out, then reduce jet? or am i looking at air corrector change, eg 140 to 120?

I need to take the scooter on a 10-15 mile run to work and back to get the impact on spark plug colour for roadshide chop, photo and put on here, but part of me is feeling a little nervous about being spat off from a seize. But im hoping that having the BE4 with AC140 and a 120 MJ for testing i will be ok. Must be radically different to what i had before with AC190 and 116 MJ so any reassurances greatful as feel like losing my nerve a bit.

Thanks all.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2907
Location: Staten Island, NY
Tue Apr 06, 2021 7:25 am quote
Be4 to be3 is multiple steps leaner in the mid throttle. Not richer.
Sounds like you are close already with just that change. If i were you I'd stay at 140ac and buy a 120, 122 and 125 main jet. Maybe even 128 if you don't get rich bogging at 125. This way you can confirm you are too rich on main then work down those until the bogging is gone. Most likely you'll end up around 122 or 120.

As far as drilling carb float passage, you don't have a fast flow tap so even if you drilled it, you still have a bottleneck in the flow, just moved from carb to fuel tap. Don't bother until you test those jets first.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Tue Apr 06, 2021 7:50 am quote
swiss1939 wrote:
Be4 to be3 is multiple steps leaner in the mid throttle. Not richer.
Sounds like you are close already with just that change. If i were you I'd stay at 140ac and buy a 120, 122 and 125 main jet. Maybe even 128 if you don't get rich bogging at 125. This way you can confirm you are too rich on main then work down those until the bogging is gone. Most likely you'll end up around 122 or 120.

As far as drilling carb float passage, you don't have a fast flow tap so even if you drilled it, you still have a bottleneck in the flow, just moved from carb to fuel tap. Don't bother until you test those jets first.
I do have a fast flow tap. Its the newer Sip Version. I used to have issues with my old tap when the tank was only half full, it wouldnt feed petrol at high revs. Gravity issues. The fast flow tap sorted all that nonsense out. Just out of confusion, charlieman stated "That float bowl hole I mentioned will struggle to feed more than about a 118/120 jet.
That means if you put a 130 in - it will still only behave like a 120." How might a 125 jet make any difference to me if this is the case? I can go online and order those jets for sure, but trying to learn all this and sometimes my understanding gets conflicted. Thank you Swiss. Yes, scoot sounds a lot happier and it was actually sleeting out whilst i was driving. So its a good test to do my carb stuff now whilst the air is really cold.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2907
Location: Staten Island, NY
Tue Apr 06, 2021 8:13 am quote
My point was if you didn't have fast flow, drilling the carb wouldn't make a difference because you would still have the bottleneck but further up the fuel line.

So drill the float passage to 2mm or 2.2mm and you will be good to use any main jet.128 main jet=1.28mm, so drilling the float hole to 2 means no chance of restricting flow.
Hooked
2005 Stella 2T
Joined: 14 Jun 2020
Posts: 119
Location: MA
Tue Apr 06, 2021 8:31 am quote
Your report sounds very encouraging.

Again, if you're not bogging with the BE5, you do not need the BE4. Try the AC140/BE5 combo with an MJ120 and an MJ122. Most likely, one of those will splutter at WOT confirming that the next main jet down is the one you want to complete your main stack.

Swiss is right, the mixer tube numbers are not in order of richness vs. leaness. See attached. The main mixer tubes from lean to rich are the BE3, BE1 and BE5. The BE4 is very rich. Its purpose in life is to cure mid throttle lean bog, but it forces you go up on the air tube or down on the main jet to get good results at WOT.

vivo_tech_jets_atomisers_01_zps134bc6b0.jpg

Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Tue Apr 06, 2021 9:05 am quote
Ok thanks guys. As soon as those 120 and 122 jets show up i will try with the be5 and get a longer run in too to report on the plug state. Getting ahead of myself, i want to revisit putting the polini box back on. Does anybody know the difference in jetting from a sip road 2.0 to a polinibox? cheers
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1580
Location: Rochester, Minnesota
Tue Apr 06, 2021 2:17 pm quote
Do you have the resources to drill out that passage? If you can get that done it may richen up your mixture also.

Last edited by Christopher_55934 on Wed Apr 07, 2021 10:51 am; edited 1 time in total
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Wed Apr 07, 2021 9:03 am quote
Well im really hoping that i dont need to drill out anything. But im sure its doable if it comes to that. What im trying to get my head around that such a non thrills DR177 bolt on with a box pipe needs such a radical amount of carb adaptation. Why would a DR177 need such high jetting? So taking a standard p200e with a polini box pipe, how many points on main jet would this need over stock? I think the various P200Es varied between a 116 and 118 main jet depending on model, so would this be something like a 125 jet for a p200 with polini box? So yes, i can get adaptations made on carb as friend is engineer if needs be. Thanks guys.
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2907
Location: Staten Island, NY
Wed Apr 07, 2021 9:17 am quote
My guess.. your rpms are higher on the pnp 177 than a stock p200 barrel. A P200 stock has more power with less effort... so the engine doesn't suck as much fuel. Your DR177 is now pushing more rpms to get similar performance as the p200 engine, so the engine needs more fuel to meet those power needs and the higher rpms needs more lubrication to stay cool.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Wed Apr 07, 2021 10:03 am quote
Well hoping the jets turn up tomorrow so i can finally find its optimum spot whilst using the road 2.0 exhaust. If its happy on the 118 jet thats in it now, i might get away with a 122 jet for the polinibox and not have to bore the carb out. I might get away with the 120 but it states on polinibox to go 3 ooints over the road 2.0. I think this is where christopher was going asking whether i have facility to drill it out. Im assuming that fitting a 124 main wont work to full effect on my 24mm carb unless drilled. Lots of run outs and plug chopping ahead. Ive got a different pilot jet on the way too the 52/140, thanks Swiss for explaining pilot jet differences between 125 and 200. Its definitely running a bit rich on the 30mph runs i do, which is pretty much everywhere around here as thats the speed limit. Im not touching the pilot until the top end tuning sorted so no doubt i will be back on here to annoy you for advice. That stupid damn starter motor on my px. Its never worked and is sure to give me a headache getting to that mix screw. Are the starter motors easy to get off?
Ossessionato
VSX, Stella 177, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 2907
Location: Staten Island, NY
Wed Apr 07, 2021 10:18 am quote
Yup.

Three nuts to remove. Plus disconnect the electrical connection on the starter motor.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Wed Apr 07, 2021 10:21 am quote
swiss1939 wrote:
Yup.

Three nuts to remove. Plus disconnect the electrical connection on the starter motor.
Well that crock of shite is coming off soon. Ive always been a kick start man. So just cable tie the electrical connections off somewhere? Its such a hindrance for access to carb mixer.
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 & 96 Elite 80s, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3926
Location: Oceanside, CA
Wed Apr 07, 2021 11:02 am quote
ferriswolf wrote:
swiss1939 wrote:
Yup.

Three nuts to remove. Plus disconnect the electrical connection on the starter motor.
Well that crock of shite is coming off soon. Ive always been a kick start man. So just cable tie the electrical connections off somewhere? Its such a hindrance for access to carb mixer.
If you remove the starter, make sure to blank off the hole in the cases!

If you have a dremel tool, Iíd trim and notch the mixture screw. That way you can lift the carb straight up out of the box AND you can turn it with a flat screwdriver rather than a 7mm socket with extensions fighting the kickstarter etc. etc.
Molto Verboso
2007 Stella 225
Joined: 02 Nov 2019
Posts: 1580
Location: Rochester, Minnesota
Wed Apr 07, 2021 12:40 pm quote
ferriswolf wrote:
swiss1939 wrote:
Yup.

Three nuts to remove. Plus disconnect the electrical connection on the starter motor.
Well that crock of shite is coming off soon. Ive always been a kick start man. So just cable tie the electrical connections off somewhere? Its such a hindrance for access to carb mixer.
Put something insulating such as shrink tubing on the wires. Wouldn't want that wire to be touching metal and have someone press the start button.
Hooked
PX
Joined: 28 May 2020
Posts: 106
Location: Bognor Regis
Fri Apr 09, 2021 2:44 am quote
Update. dr177, 24mm SI, sip road 2.0, drilled filter.

Im now on an AC140 BE5 and 120 main jet. 50/120 pilot Just put in new plug and thrashed to chichester and back on a dual carriageway. So 16 mile round trip. I think im on the money for the plug colour. Chocolate strap on top and centre. Can you guys advise?

Im still a bit gurgley on tiny throttle in low gears but i have a leaner pilot jet on standby the 52/140 (thank swiss for this info). Im hoping this will even it out.

Now hoping i have a good base setup to proceed. I want to move to the polinibox going back on. Im hoping i will get away with the 122 jet and my carb will be happy I do have SIP fast flow tap (latest one). The next jet size from 122 is 125 so that will be five points over where im at now. The issue of the carb being able to handle that jet is also in question. It was mentioned about drilling so i guess all i can do is give it a go and be guided by the plug colour.

IMG_2909.jpg

  DoubleGood Vespa T-Shirts  
Post Reply    Forum -> Not-So-Modern
[ Time: 0.2717s ][ Queries: 52 (0.1311s) ][ Debug on ]