Thu May 19, 2022 4:00 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 4:00 am linkquote
Good afternoon.

I have a Vespa PX 150 fitted with a Pinasco 60mm crank, Pinasco Vespone 190cc kit and 20/20 carb. Jets are 140/BE5/112 with 52-140 idle. I am just running the engine in. I have a Polini Road exhaust fitted.

When I rev the engine, the revs take longer to settle back to idle than normal. I have been told this is an idle jet/mixture screw setting. The mixture screw is 3.5 turns out.

I changed idle jet to 50-120 to richen it out a bit. However, this has made the issue worse. The revs tend to hang for a good 5 - 10 seconds before settling. Sometimes longer. All carb gaskets are new so I don't think it's an air leak.

I am confused how a richer idle jet made the issue worse.

Any ideas?

Thanks.
Thu May 19, 2022 4:55 am

Hooked
PK50XL, PK100S, ET3
Joined: 26 Aug 2020
Posts: 267
Location: UK
 
Hooked
PK50XL, PK100S, ET3
Joined: 26 Aug 2020
Posts: 267
Location: UK
Thu May 19, 2022 4:55 am linkquote
Air leak?
Thu May 19, 2022 5:03 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 5:03 am linkquote
Seals are all good. Everything seems fine. Although I have not pressure tested it as I have no means on doing so. How would making it richer increase the revs? Surely this would counteract the air leak and balance it out?
Thu May 19, 2022 5:25 am

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 Elite 80,90 V5N 50, 01 ET2, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
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Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 Elite 80,90 V5N 50, 01 ET2, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4410
Location: Oceanside, CA
Thu May 19, 2022 5:25 am linkquote
Next time you try, rev up and before the revs totally settle back to idle, pull the choke. The choke is an enricher. If the revs immediately come down, the motor wants more fuel. If it bogs and dies, it's getting too much fuel and your idle jet is probably good. Make sense?
Thu May 19, 2022 5:30 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 5:30 am linkquote
Hi.

At idle when I apply the choke, the engine stalls after a few seconds which leads me to believe its not running lean. Thank you for the advice.
Thu May 19, 2022 5:31 am

Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
 
Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
Thu May 19, 2022 5:31 am linkquote
Did you rule out a binding throttle cable? Does it do it with the throttle cable disconnected? I would start there and then move on to the carb itself if throttle cable and linkage check out.

Hec
Thu May 19, 2022 5:34 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 5:34 am linkquote
Hi.

I have checked the throttle cable and it appears fine. I will try without the cable connected though just to rule it out. Thank you for your advice.
Thu May 19, 2022 6:05 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 6:05 am linkquote
MJRally wrote:
Next time you try, rev up and before the revs totally settle back to idle, pull the choke. The choke is an enricher. If the revs immediately come down, the motor wants more fuel. If it bogs and dies, it's getting too much fuel and your idle jet is probably good. Make sense?
The engines slows right down and stalls.
Thu May 19, 2022 10:49 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 10:49 am linkquote
Also, when I increase the revs, then back off to zero throttle, the engine pops a lot on the overrun. Is this normal for a two stroke, or is this the sign of lean running? If I run with slight choke, the low revs are boggy but as the revs come down the engine does not make the popping noise.
Thu May 19, 2022 11:33 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 11:33 am linkquote
I have just screwed in the mixture screw all the way and the engine kept running. I then screwed it almost fully out and the engine kept on running with very little difference in revs between. WTFF?
Thu May 19, 2022 12:14 pm

Moderibbit
1980 P200E - "Old Rusty", 1976 ET3 Primavera
Joined: 12 Jun 2008
Posts: 8867
Location: Atlanta, GA
 
Moderibbit
1980 P200E - "Old Rusty", 1976 ET3 Primavera
Joined: 12 Jun 2008
Posts: 8867
Location: Atlanta, GA
Thu May 19, 2022 12:14 pm linkquote
did you do the test yet with the throttle cable disconnected?

Also, just throwing stuff at the wall here, but you're testing the mixture screw on a good hot engine and you're waiting a while after each bit of turn before determining if it did anything, right? Because it's a a slow effect
Thu May 19, 2022 12:17 pm

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Thu May 19, 2022 12:17 pm linkquote
Yes I did the check with the cable disconnected. I am waiting for the change. The engine was nice and warm after a good run. Normally takes a few seconds for the mixture screw to take effect but nothing. Very odd.
Thu May 19, 2022 3:40 pm

Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
 
Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
Thu May 19, 2022 3:40 pm linkquote
I think you have a clogged idle circuit. I'd pull the carb and completely disassemble it and soak all metal parts in a boiling pot of 25% simple green and 75% water. Boil it for 30 mins and then rinse the carb thoroughly. Blow out all passages and orifices with compressed air and reassemble.

Good luck
Fri May 20, 2022 5:33 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Fri May 20, 2022 5:33 am linkquote
I cleaned out the card as best I could with carb cleaner and compressed air. No difference. I have gear oil leaking from the carb area? Weird. Also, when I remove the idle jet when running, the engine dies which is good.
Fri May 20, 2022 5:46 am

Moderibbit
1980 P200E - "Old Rusty", 1976 ET3 Primavera
Joined: 12 Jun 2008
Posts: 8867
Location: Atlanta, GA
 
Moderibbit
1980 P200E - "Old Rusty", 1976 ET3 Primavera
Joined: 12 Jun 2008
Posts: 8867
Location: Atlanta, GA
Fri May 20, 2022 5:46 am linkquote
are you sure it is gear oil from the carb area? My guess is it's the typical skanky 2t oil-fuel stuff dribbling out the back (typically around the adjustment screws)? Pics?
Fri May 20, 2022 7:02 am

Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
 
Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
Fri May 20, 2022 7:02 am linkquote
Do you notice puffs of vapor blowing out the top of the carb when the engine speed is winding down after revving? Try this, hold a clean sheet of white paper over the top of the carb with the air cleaner removed. Give it a rev and see if there is any evidence of wetness on the paper. If so the rotary valve clearance is too big. This condition would allow unburned fuel/oil mix to escape through the carb. The fuel will then evaporate in the carb box and leave the two stroke oil behind. Maybe this explains the oil you are seeing? I am new to the Vespa Scene so I may be out to lunch on this. Just thinking out loud.

Hec

Last edited by Hec In Omaha on Fri May 20, 2022 1:11 pm; edited 1 time in total
Fri May 20, 2022 8:05 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Fri May 20, 2022 8:05 am linkquote
With the air filter off, fuel does blow out of the carb but I was told this is normal to some extent. If this is an issue, how do you reduce the gap and bring within tolerance? Not too sure about the oil. It seems to gather near the mixture screw and dribble down.
Fri May 20, 2022 8:11 am

Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 Elite 80,90 V5N 50, 01 ET2, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
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Location: Oceanside, CA
 
Ossessionato
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 86 Elite 80,90 V5N 50, 01 ET2, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 4410
Location: Oceanside, CA
Fri May 20, 2022 8:11 am linkquote
Do you have a YouTube account? Film it and post the YouTube link on here. Otherwise we're gonna keep guessing.
Fri May 20, 2022 8:14 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Fri May 20, 2022 8:14 am linkquote
I replaced the idle jet with a 50/120 and turn out the mixture screw 3.5 turns. It seems to run a lot better now. Still not perfect but better. I am sending the bike to a Vespa specialist to get it checked out. I don't want to just mask the issue by making it richer. I will update you when I find out what the issues are. Thank you once again for all your help.
Fri May 20, 2022 8:16 am

Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
 
Enthusiast
1980 P125X US Spec
Joined: 13 Jan 2022
Posts: 59
Location: Beaver Lake, Nebraska USA
Fri May 20, 2022 8:16 am linkquote
Here is a good video of Rotary Valve Repair.

Fri May 20, 2022 8:56 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
Fri May 20, 2022 8:56 am linkquote
roody76 wrote:
I replaced the idle jet with a 50/120 and turn out the mixture screw 3.5 turns. It seems to run a lot better now. Still not perfect but better. I am sending the bike to a Vespa specialist to get it checked out. I don't want to just mask the issue by making it richer. I will update you when I find out what the issues are. Thank you once again for all your help.
Save your money. 50/120 is functionally leaner at idle than a 52/140. Put in a 55/160 and then see what happens. All will be near perfect I'm sure.
If anything is actually wrong with it it will be very obvious.
Fri May 20, 2022 11:14 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Fri May 20, 2022 11:14 am linkquote
I was told that the new idle jet is richer if you divide the top number by the bottom. The lower the number, the richer it is. This is getting very confusing. Is that jet stack incorrect or pretty safe for hammering it? Why is is the mixture screw does not really do much? Fully closed engine runs. Fully open engine runs.
Fri May 20, 2022 2:15 pm

Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
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Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
Fri May 20, 2022 2:15 pm linkquote
The pilot jet dividing thing is true but not even half the story. Not surprised you're having issues.
That vespone kit is probably the RX version, which is the best of the range and has a lot of potential if set up well.
To make it go fast and not damage it, the jetting is going to need to be much richer. The 20/20 is small for it but sure you know that already. The current jetting will wear it out before it's run in.
The stock filter can't cope and has to go, run with either a vortex or nothing. AC120/BE4 is not for discussion. 55/160 pilot and main jet at 130 to start with. Hopefully you have the squish at 1mm. Timing set precisely. And a SIP 2.0 tap.
Polini exhaust is restrictive for this kit but it will help it wheelie well.
Sat May 21, 2022 1:03 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 1:03 am linkquote
I bought the bike with the same kitted fitted but it seized on me. It had been built by reedspeed and put on the dyno with the jetting as: 140/BE5/105 with 52/140 idle. It has a upgraded chamber cover and hole in carb for main jet drilled to 2.5mm. It seized on me at WOT after a good 5 or 10 mins. Massive soft seize on the intake side of piston. It was well and truly melted. I have upgraded the main jet to 112 and the plug colour is a medium brown. It feels rich when pulling away as it splutters a bit put then picks up nice. I cant see how reedpseed would set it up incorrect and a main of 130 seems huge. I have fitted a sip 2 tap. Running autolube with 1% extra in tank. Squish is quite high at 1.4mm. Cant get it any lower unless I remove the base gasket. Port height is good for all ports. Timing on stator is retarded as far as it will go to the IT setting. Compression is 170 PSI cold and 155 PSI after a run and warmed up. Its a 2016 PX150E.
Sat May 21, 2022 5:06 am

Hooked
2005 Stellalossi 177 Fe
Joined: 14 Jun 2020
Posts: 281
Location: MA
 
Hooked
2005 Stellalossi 177 Fe
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Posts: 281
Location: MA
Sat May 21, 2022 5:06 am linkquote
roody76 wrote:
It had been built by reedspeed and put on the dyno with the jetting as: 140/BE5/105 with 52/140 idle.
Something must be getting lost in translation. Nobody would put a 105 main jet on a "190" kit.
Sat May 21, 2022 5:22 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 5:22 am linkquote
Well that's how it came to me. I put around 600 miles on it before it seized up. If it was that lean, it would have seized a lot sooner than that. I am very confused on the jetting setup. Considering it was put on a dyno, kicking out 17HP with that jetting, it must have been ok.
Sat May 21, 2022 5:25 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
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Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
Sat May 21, 2022 5:25 am linkquote
A Dyno is a tool. They only seize and melt when seriously lean. Not just a bit lean, like 20% lean.
Not saying 130 is the jet, just that with the AC120/BE4 it will be where to start from.

The 2016 model has a rev limiter on the CDI. I take it this has been changed? 1.4 squish big but ok for now. Rest sounds good. Carb drilled especially. Timing needs to be set precisely with your own timing marks.

Will never go properly with the filter in the carb box. Needs to go in the bin.
Get it rejetted it will be fine.
Sat May 21, 2022 5:33 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 5:33 am linkquote
So I have been told that the dyno was complete with a normal air filter on the bike. It now has an air filter with the holes above the jets. So the guy has told me to upjet it to at least 120 and go from there. I find out new things about this bike every day. Yes the ignition has been changed to Zeus unit. I have ordered some new jets so they should be here soon. No wonder it's been a bit off.
Sat May 21, 2022 6:01 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
Sat May 21, 2022 6:01 am linkquote
If you keep any original style air filter it will end in tears. This kit is way beyond stock filter setups.
Sat May 21, 2022 6:20 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 6:20 am linkquote
Is it ok to run with the filter completely removed or what filter would you recommend fitting? Thanks.
Sat May 21, 2022 7:35 am

Ossessionato
2007 Stella 225
Joined: 02 Nov 2019
Posts: 2923
Location: Rochester, Minnesota
 
Ossessionato
2007 Stella 225
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Location: Rochester, Minnesota
Sat May 21, 2022 7:35 am linkquote
roody76 wrote:
Is it ok to run with the filter completely removed or what filter would you recommend fitting? Thanks.
As long as you put top on and snorkel to frame no filter is fine. Keeps big chunks out of system. I installed this bell mouth which helps correct airflow. I was skeptical, however when I had to go up several jet sizes I was convinced, something like 10 sizes.

https://www.shapeways.com/product/ZFBJ7HCAE/20mm-largeframe-vespa?optionId=451888&li=marketplace


After you get this working, pay attention to when and how often you find yourself at wide open throttle. You should be able to run a 24mm carburetor no problem, will bolt on. Intake area is 25% bigger allows more air flow to utilize that kit you have better.
Sat May 21, 2022 7:50 am

Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9A1T, V9B1T
Joined: 20 Jul 2018
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Location: Staten Island, NY
 
Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9A1T, V9B1T
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Posts: 3904
Location: Staten Island, NY
Sat May 21, 2022 7:50 am linkquote
Christopher_55934 wrote:
As long as you put top on and snorkel to frame no filter is fine. Keeps big chunks out of system. I installed this bell mouth which helps correct airflow. I was skeptical, however when I had to go up several jet sizes I was convinced, something like 10 sizes.

https://www.shapeways.com/product/ZFBJ7HCAE/20mm-largeframe-vespa?optionId=451888&li=marketplace


After you get this working, pay attention to when and how often you find yourself at wide open throttle. You should be able to run a 24mm carburetor no problem, will bolt on. Intake area is 25% bigger allows more air flow to utilize that kit you have better.
Side note.. have you noticed any difference between running no filter and with this bell mouth? My understanding is there is no real difference. I run with no filter on my 177 tuned Stella.
Sat May 21, 2022 7:50 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 7:50 am linkquote
I have just drilled out a main jet to 1.3mm which I believe equates to a 130 jet? It has made a big difference. The bike will only rev to 6500 rpm and is very smokey. It also ticks over a lot better but the bike still runs with the mixture screw right in. The revs go up but it still runs. Where is it getting the fuel from if the mixture valve is closed. On the main jet side of things, 130 is too big so I will work down from that. Maybe a 120 or 122.
Sat May 21, 2022 7:52 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 7:52 am linkquote
swiss1939 wrote:
Side note.. have you noticed any difference between running no filter and with this bell mouth? My understanding is there is no real difference. I run with no filter on my 177 tuned Stella.
I am going to invest in a 24/24 carb. I will have to then start again with the jetting. I have no real idea where to start. All jets will need carefully selecting. I may be back on here asking for help. Lol.
Sat May 21, 2022 7:56 am

Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9A1T, V9B1T
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Location: Staten Island, NY
 
Ossessionato
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Location: Staten Island, NY
Sat May 21, 2022 7:56 am linkquote
roody76 wrote:
I have just drilled out a main jet to 1.3mm which I believe equates to a 130 jet? It has made a big difference. The bike will only rev to 6500 rpm and is very smokey. It also ticks over a lot better but the bike still runs with the mixture screw right in. The revs go up but it still runs. Where is it getting the fuel from if the mixture valve is closed. On the main jet side of things, 130 is too big so I will work down from that. Maybe a 120 or 122.
If your main jet is sooo big, it will bleed into the idle at idle and prevent it from stalling if the air mix screw is all the way in. But you need to find your correct main jet before you start worrying about fixing the idle that won't die with af screw all the way in. Just set idle to a safe idle jet size with the af screw set correctly for your carb.. 1.5 turns out on newer carbs and 2.5 turns out on old carbs.

Both circuits are connected so you need a generic baseline idle that you leave as constant until you get the main closer. Once you get the main closer you can go back and fine tune the idle.
Sat May 21, 2022 8:07 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 8:07 am linkquote
It still runs with the screw closed with an 112 main so I don't know what is going on. Maybe an air leak somewhere. I thought it was 2.5 turns out for newer carbs with the finer thread on the 7mm screw?
Sat May 21, 2022 8:20 am

Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9A1T, V9B1T
Joined: 20 Jul 2018
Posts: 3904
Location: Staten Island, NY
 
Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9A1T, V9B1T
Joined: 20 Jul 2018
Posts: 3904
Location: Staten Island, NY
Sat May 21, 2022 8:20 am linkquote
roody76 wrote:
It still runs with the screw closed with an 112 main so I don't know what is going on. Maybe an air leak somewhere. I thought it was 2.5 turns out for newer carbs with the finer thread on the 7mm screw?
Can never keep it straight in my mind.
Sat May 21, 2022 8:23 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 8:23 am linkquote
It's getting picked up next week for a guy to sort it out. I have reached the limit to what I can do. The issues just don't make sense anymore. Pissing me off. Lol.
Sat May 21, 2022 9:02 am

Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
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Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX172 Quattrini and some motorbikes
Joined: 14 Jun 2017
Posts: 3339
Location: London UK
Sat May 21, 2022 9:02 am linkquote
roody76 wrote:
I have just drilled out a main jet to 1.3mm which I believe equates to a 130 jet? It has made a big difference. The bike will only rev to 6500 rpm and is very smokey. It also ticks over a lot better but the bike still runs with the mixture screw right in. The revs go up but it still runs. Where is it getting the fuel from if the mixture valve is closed. On the main jet side of things, 130 is too big so I will work down from that. Maybe a 120 or 122.
What size air corrector with that drilled jet? Filter off?
Idle won't work until you fit a 55/160

Keep at it plenty of us here
Sat May 21, 2022 9:29 am

Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
 
Hooked
2016 PX 150 (Pinasco Vespone RX 190(On the mend))
Joined: 19 May 2022
Posts: 234
Location: UK - North East
Sat May 21, 2022 9:29 am linkquote
It's a 140 air corrector and BE5 tube. Filter off with just the cover on.
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