Tue Jul 26, 2022 9:30 pm

Hooked
Parmakit Primavera -74, Polini Primavera -68, Stock 150 Touring -59, VMC 177 Bajaj Chetak 125 -95
Joined: 22 Jun 2022
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Location: Finland
 
Hooked
Parmakit Primavera -74, Polini Primavera -68, Stock 150 Touring -59, VMC 177 Bajaj Chetak 125 -95
Joined: 22 Jun 2022
Posts: 388
Location: Finland
Tue Jul 26, 2022 9:30 pm linkquote
I don't think so. An engine will run even if the plug is just fingertight.
Wed Jul 27, 2022 1:30 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3434
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3434
Location: London UK
Wed Jul 27, 2022 1:30 am linkquote
It might not have seized, just overheated. 300f at 1/2 throttle is way too hot for a low power kit, just bolted on.

Timing or jetting. If you're still running the BE3 it's probably too that. Should be a 5 or a 4.

Unlikely to be any damage done.
Wed Jul 27, 2022 9:44 am

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Wed Jul 27, 2022 9:44 am linkquote
Jack221 wrote:
It might not have seized, just overheated. 300f at 1/2 throttle is way too hot for a low power kit, just bolted on.

Timing or jetting. If you're still running the BE3 it's probably too that. Should be a 5 or a 4.

Unlikely to be any damage done.
Something to work at. I just gave the timing a tweak -- it was pretty close to 19° as the DR 177 seems to want, but now the scoot doesn't want to idle. Smells really rich. So I'm walking away to cool off for a bit. Followed this guide https://www.youtube.com/watch?v=MNEljKGfGpc&t=0s.

This was jetting for that ride. If anything, wouldn't this be rich?
Atomizer: BE4
Main Jet: 115
Air Jet: 140
Idle Jet: 52/140
Air mix screw out 1-1/2 turns
Wed Jul 27, 2022 10:01 am

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Wed Jul 27, 2022 10:01 am linkquote
The best base pilot for 177 kits is 55/160 then iron out with the pilot screw imo
Wed Jul 27, 2022 12:33 pm

Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3434
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3434
Location: London UK
Wed Jul 27, 2022 12:33 pm linkquote
With that jetting. Probably rich at idle. And lean at WOT.

As said put in the 55/160, then increase the main jet until the revs drop when held wide open while on the stand. Splutters badly and won't rev out. Write down this main jet number.
Wed Jul 27, 2022 1:55 pm

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Wed Jul 27, 2022 1:55 pm linkquote
It's been mentioned earlier that 140 be5 and 121 to 125 is where it's likely to be at, especially for dr177! If you're on standard pipe possibly a 118, but go high on jet, wot on third till it no longer rich bogs, stepping jet size down till it's smooth then stop there. Use a 55/160 or 50/140 pilot and weaken or rich up using pilot screw depending on where you're at. This doesn't have to be complicated. 115 jet is way too low imo. Then do your plug chops after idle running, mid range running and WOT max speed fourth. See where you're at then , very likely correct.
Wed Jul 27, 2022 4:05 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Wed Jul 27, 2022 4:05 pm linkquote
ferriswolf wrote:
It's been mentioned earlier that 140 be5 and 121 to 125 is where it's likely to be at, especially for dr177! If you're on standard pipe possibly a 118, but go high on jet, wot on third till it no longer rich bogs, stepping jet size down till it's smooth then stop there. Use a 55/160 or 50/140 pilot and weaken or rich up using pilot screw depending on where you're at. This doesn't have to be complicated. 115 jet is way too low imo. Then do your plug chops after idle running, mid range running and WOT max speed fourth. See where you're at then , very likely correct.
Yah, those were jets suggested when I was trying to get the SI 24/24G and stock exhaust working. I'm back to the original 20/20D but with SIP Road installed and it seems to be a whole different ball game.

https://modernvespa.com/forum/topic153638
This dude settled on 108/BE3/160 in the main stack and 48/160 idle jet. But he was running 3% mix.

https://modernvespa.com/forum/topic166699
Meanwhile, this dude seized right up with 140/BE5/105. Main was too lean.

https://modernvespa.com/forum/topic180743
And then I went down a whole rabbit hole with this guide which led me to where I am today with the SI 20/20D. 140/BE4/115 + 52/140. My carb does have a funny throttle slide (#7), shared with all the Cosa 125 models. There's all kinds of numbers getting thrown around.
Thu Jul 28, 2022 7:26 am

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Thu Jul 28, 2022 7:26 am linkquote
Can you buy a standard 24mm si? We all know on here the jetting for that especially for DR177 and road 2 pipe. You won't blow up your kit and for sake of 80 quid if not cheaper you will be bang on the money with jets we have suggested .
Thu Jul 28, 2022 8:00 am

Veni, Vidi, Posti
'15 GTS300, '86 PX125EFL, '66 VBB, '04 Ninja 250
Joined: 04 Apr 2013
Posts: 6497
Location: San Diego, CA
 
Veni, Vidi, Posti
'15 GTS300, '86 PX125EFL, '66 VBB, '04 Ninja 250
Joined: 04 Apr 2013
Posts: 6497
Location: San Diego, CA
Thu Jul 28, 2022 8:00 am linkquote
that slide will matter - why not run something more ordinary?
Sat Aug 13, 2022 2:23 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Sat Aug 13, 2022 2:23 pm linkquote
P80X update! I've been taking it easy with a 55/160 idle jet, and 140/BE5/122 stack. It's pretty happy and under 300F in first through third gears. Fourth gear WOT is shooting up and over 300F, so I'm still in fiddle town, and I have had a couple of instances of the engine dying under throttle as I pull out of a stop in first gear. I've had to let it sit for a few minutes before it'll start again.

I noticed that things were looking a little "slick" inside the rear fender and on the engine side of the rear brake plate. Yeah, my crankcase breather vent worked itself free. Besides spewing forth gear oil, would this impact performance at all? Just curious.


Late night snack run.



Last edited by meltshow on Sun Aug 14, 2022 6:00 am; edited 1 time in total
Sat Aug 13, 2022 4:01 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Sat Aug 13, 2022 4:01 pm linkquote
Popped off the airbox to install a spare crank breather. This gasket…did I put the wrong one on? I think I put the wrong one on. Is it expected to be this oily?

Update: Yeah, that's the right one. Had the wrong gasket between carb and air box though.


This gasket is pretty soupy.

Sat Aug 13, 2022 6:22 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
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Posts: 47
Location: Fairfield, CA
Sat Aug 13, 2022 6:22 pm linkquote
Okay. So I swapped in a #1 throttle slide from my spare SI 20/20 (off a P200E) to give it a whirl, and it was sad times. The engine barely idled with the idle adjustment screw all the way in. It idled...mostly fine with the original #7 slide, but wasn't really smooth. Kind of wandered a bit, but not as badly as I've seen with 4T motors with an intake leak. I'm also spewing quite a bit of gear oil out the breather, and it's definitely not overfilled.

I never did a benchtop leak test (didn't know that was a thing when I had it out), but a test with a cylinder compression gauge is only returning 80 psi. So low. Should be 110-120 yeah? My mind is in a place where I'm thinking I need to pull the engine out. I have a feeling that clutch-side seal is toast, and it's why I'm seeing gear oil spew, low compression, poor kick-starting (takes 3-10 kicks) and always seem a little lean.

It'll also be an opportunity to really look at my cylinder and piston, after that seize I had the other month. It's just a bummer.
Sat Aug 13, 2022 9:30 pm

Hooked
Parmakit Primavera -74, Polini Primavera -68, Stock 150 Touring -59, VMC 177 Bajaj Chetak 125 -95
Joined: 22 Jun 2022
Posts: 388
Location: Finland
 
Hooked
Parmakit Primavera -74, Polini Primavera -68, Stock 150 Touring -59, VMC 177 Bajaj Chetak 125 -95
Joined: 22 Jun 2022
Posts: 388
Location: Finland
Sat Aug 13, 2022 9:30 pm linkquote
Bad seal would explain your woes quite too well.

You can verify by dropping your oil and giving it a smell. If they smell like gasoline, it's time for an engine rebuild.
Sun Aug 14, 2022 12:40 am

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Addicted
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Sun Aug 14, 2022 12:40 am linkquote
That idle jet seems too lean imo for a DR . On top of your other issues , when sorted I'd richen that up.
Mon Aug 15, 2022 9:01 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
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1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Mon Aug 15, 2022 9:01 pm linkquote
I think what I'm gonna do is pull this P80X engine and replace it with a P200E engine I got last week, so I can at least ride around while sorting out the P80X situation. It'll allow me to remain patient and get it just right.
Tue Aug 16, 2022 7:13 am

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Tue Aug 16, 2022 7:13 am linkquote
meltshow wrote:
I think what I'm gonna do is pull this P80X engine and replace it with a P200E engine I got last week, so I can at least ride around while sorting out the P80X situation. It'll allow me to remain patient and get it just right.
. Just leave the p2 engine in , vastly more comfortable to drive than a DR177 rattler
Fri Aug 19, 2022 10:47 am

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Fri Aug 19, 2022 10:47 am linkquote
Noknown idea of what it would cost to overhaul the P200E engine, we're back to this lovely little lump. I pulled the engine last night, plopped it on the ,workbench and began to tThe firstn.

First sign of strange goings-on was a definite whiff of fuel in the gear oil as it drained. So I know I have a clutch-side seal to replace, at the very least.

Take a gander with me at the worn state of the DR 177 cylinder. Ladies and gentlemen, we have scoring along the exhaust side of the cylinder. Back when I was prepping the kit for installation, I did chamfer the cylinder port edges, and they still seem pretty good. Still, I am open to the possibility that I did all of that wrong, and that's why we've got the damage. However, I did have a pretty spectacular hard seize a couple of months ago in which my life flashed before my eyes, so I'd imagine that's where the initial damage occurred.

I can feel that scoring with a fingernail through a pair of gloves. It's the real deal, so the next step is to hone it out and see how overbored I end up. I will continue digging in and working on getting those seals settled.


P80X engine out and on the bench.


Toasty piston head


Mangled cylinder down by exhaust port


Piston scoring along the bottom side.


Also cylinder head weeping a bit? Or just from me opening the cylinder.

Fri Aug 19, 2022 10:58 am

Ossessionato
1979 P150X, 1983 P200E, 1988 T5, 1995 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 3198
Location: Veria, Greece
 
Ossessionato
1979 P150X, 1983 P200E, 1988 T5, 1995 PX200E, 2011 Yamaha Fazer 600 S2
Joined: 02 Aug 2015
Posts: 3198
Location: Veria, Greece
Fri Aug 19, 2022 10:58 am linkquote
Probably sucking oil from the gearbox. Clutch seal or gasket near the primary. FMP on YouTube has a video on how to join the cases and avoid the "oil sucking problem"…
Fri Aug 19, 2022 1:07 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
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Posts: 47
Location: Fairfield, CA
Fri Aug 19, 2022 1:07 pm linkquote
SaFiS wrote:
Probably sucking oil from the gearbox. Clutch seal or gasket near the primary. FMP on YouTube has a video on how to join the cases and avoid the "oil sucking problem"…
Super helpful! Here's the video for anyone looking for it in the future.

https://www.youtube.com/watch?v=Yjxk4StYH7w
Fri Aug 19, 2022 10:10 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
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Posts: 47
Location: Fairfield, CA
Fri Aug 19, 2022 10:10 pm linkquote
Did you know you can install a clutch-side seal backwards?


Yes.


I have a feeling all of my gaskets being soaked with oil didn't help either.

Wed Sep 07, 2022 1:53 pm

Hooked
'81 Special, '81 P150X, '87 PK50 Nuova '13 LML Star 200
Joined: 30 Nov 2018
Posts: 210
Location: Ukraine. Kyiv.
 
Hooked
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Joined: 30 Nov 2018
Posts: 210
Location: Ukraine. Kyiv.
Wed Sep 07, 2022 1:53 pm linkquote
Sorry if this is no longer relevant for you.

Jets what I have on my P150X with p'n'p DR177 with Malossi cylinder head, Mazz racing crank, drilled SI 24/24 E and SIP Road 2 exhaust and drilled air filter.
AC 160
Mixer BE3
Main 125
Idle 55/160
Mix 2.5 out

I ride on my P more than 10000 km for long and short distances and everything is perfect.
Thu Sep 22, 2022 8:24 pm

Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
 
Member
1981 P80X
Joined: 18 Feb 2016
Posts: 47
Location: Fairfield, CA
Thu Sep 22, 2022 8:24 pm linkquote
ferriswolf wrote:
I run a dr177 with road 2.0 , modded filter 24mm si, matched carb inlet box, sip 2 fast flow tap, and use ac140 Be5 121 main and 50/120 pilot. I run on 7 grade heat plug B7HS and change to 8 grade for long runs. That's bang on and arrived at by the lads on this forum. As you got standard pipe I'd knock off 3 to 4 on main I've specified so 118 ish. So this is what you're looking at and pretty typical with others I know who have same setup.
Okay okay. FINALLY got my hands on a 24/24E, and I've replicated your stack. I've basically the same setup, only I've got the SIP road 3.0 and the 50/120 pilot/idle jet was too rich. A slightly leaner 52/140 seems to have done the trick. Still need to give it some time at 1/2 to 3/4 throttle in 3rd gear to see how the other jets work as far as temperatures go.

But holy cow a proper 24/24 woke it right up.
roland87 wrote:
Sorry if this is no longer relevant for you.
...
I ride on my P more than 10000 km for long and short distances and everything is perfect.
Дякую! Someone else will find this thread and have the perfect setup for a 20/20 + DR 177 thanks to you.
Fri Sep 23, 2022 12:28 am

Enthusiast
too many
Joined: 16 May 2012
Posts: 75
Location: Norway
 
Enthusiast
too many
Joined: 16 May 2012
Posts: 75
Location: Norway
Fri Sep 23, 2022 12:28 am linkquote
meltshow wrote:
Noknown idea of what it would cost to overhaul the P200E engine, we're back to this lovely little lump. I pulled the engine last night, plopped it on the ,workbench and began to tThe firstn.

First sign of strange goings-on was a definite whiff of fuel in the gear oil as it drained. So I know I have a clutch-side seal to replace, at the very least.

Take a gander with me at the worn state of the DR 177 cylinder. Ladies and gentlemen, we have scoring along the exhaust side of the cylinder. Back when I was prepping the kit for installation, I did chamfer the cylinder port edges, and they still seem pretty good. Still, I am open to the possibility that I did all of that wrong, and that's why we've got the damage. However, I did have a pretty spectacular hard seize a couple of months ago in which my life flashed before my eyes, so I'd imagine that's where the initial damage occurred.

I can feel that scoring with a fingernail through a pair of gloves. It's the real deal, so the next step is to hone it out and see how overbored I end up. I will continue digging in and working on getting those seals settled.
Hi,

According to the pics of the cylinder and cylinder head, you have had a leak there as well.
-that's where the preasure testing of a 2 stroke engine comes in to play....

That leak in addition to the faulty clutch seal has most likely fooled you.

Unless the engine is 100% air tight, it is nearly impossible to have the engine behave as it should.

When you rebuild it, preassure test it prior to putting it into the frame.


Regarding the scores around the exhaust port, it is not because of you grading the other ports. -it is because of the overheating/leaning out...
Grading the ports on a cast iron cylinder is always good.

Rgrds
Ø
Fri Sep 23, 2022 12:55 am

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: 21 Oct 2005
Posts: 11799
Location: The state of insanity, SoCal
 
Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: 21 Oct 2005
Posts: 11799
Location: The state of insanity, SoCal
Fri Sep 23, 2022 12:55 am linkquote
man, that looks rough I'd say you're probably into next over territory and at the very least a new set of rings and plenty of work to get that squared away.

frankly I'm surprised it ran that long with the clutch seal in backward. hopefully it didn't mess up your crank!

as noted your head was leaking too. lap it down, add a schmear of sealant on reassembly and follow the torque directions with an added re-torque after heat-cycling.

it'll live again. just take your time, check your work and keep everything clean. you got this.
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