Hey, new to the forum but been referencing here for a long time.
I'm having an issue post big bore that I've never experienced: No matter what jetting I run the scooter always seems to run lean. I can even jet to the point of it hardly being able to run and it still gets hot at anything but idle.
Currently running the NCY 82cc big bore kit with a 24mm Polini carb, the jet sizes are 55 and 135 respectively. The scooter also has a bigger intake and high flow exhaust on it. The fuel is currently 40:1, but I've also tried 32:1. My spark plug is an NGK B9HS. Currently checking head temps with a thermostat that goes on the spark plug
If I'm missing any more important details let me know, thanks!
82cc AF16 Odd Lean Condition
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- Wheelman-111
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- Joined: Wed Oct 22, 2008 5:09 pm
- Location: Deepinnaharta, Texas
Re: 82cc AF16 Odd Lean Condition
Greetings:
Your symptoms are very suspicious for an air leak. If you can get to idle, spray something flammable (Carb cleaner?) around the intake manifold, base gasket, head gasket and don't forget the crank end seals. If the idle changes speed you have your leak.
Your symptoms are very suspicious for an air leak. If you can get to idle, spray something flammable (Carb cleaner?) around the intake manifold, base gasket, head gasket and don't forget the crank end seals. If the idle changes speed you have your leak.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: 82cc AF16 Odd Lean Condition
I'll give that a try tomorrow, thanks for the advice!Wheelman-111 wrote: ↑Sat Apr 30, 2022 4:44 pm Greetings:
Your symptoms are very suspicious for an air leak. If you can get to idle, spray something flammable (Carb cleaner?) around the intake manifold, base gasket, head gasket and don't forget the crank end seals. If the idle changes speed you have your leak.
Re: 82cc AF16 Odd Lean Condition
Update: It was the crankshaft seal behind the variator. Thanks again for the help!Saturn wrote: ↑Sun May 01, 2022 4:27 pmI'll give that a try tomorrow, thanks for the advice!Wheelman-111 wrote: ↑Sat Apr 30, 2022 4:44 pm Greetings:
Your symptoms are very suspicious for an air leak. If you can get to idle, spray something flammable (Carb cleaner?) around the intake manifold, base gasket, head gasket and don't forget the crank end seals. If the idle changes speed you have your leak.
- Wheelman-111
- Moderator
- Posts: 11322
- Joined: Wed Oct 22, 2008 5:09 pm
- Location: Deepinnaharta, Texas
Re: 82cc AF16 Odd Lean Condition
Greetings:
Glad you found it. Not too hard to replace?
Glad you found it. Not too hard to replace?
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH