Ok I have a weird issue. Honda spree that will start but won't accelerate. Did a compression test and only got about 30 PSI. I bought a new piston, rings, head gasket, and cylinder as well as a used head for cheap just in case. Installed all of them (so basically brand new top end). Still about 35 PSI. What gives ?!?!
Tested the compression tester on another motorcycle in my garage and got 100 psi, so I know it's at least working.
Low compression
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Wheelman-111
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Re: Low compression
Greetings:
Air entering the crankcase from ANYWHERE will mess with compression... A clean Clean CLEAN cylinder/case joint and base gasket is a must.
Crank end seals let go occasionally after 25 years so need to check there as well. Air allowed to escape back into the intake through a faulty or broken reed valve will do the same. I'm betting you know this, but you have to hold the throttle wide open when you run a compression test.
Air entering the crankcase from ANYWHERE will mess with compression... A clean Clean CLEAN cylinder/case joint and base gasket is a must.
Crank end seals let go occasionally after 25 years so need to check there as well. Air allowed to escape back into the intake through a faulty or broken reed valve will do the same. I'm betting you know this, but you have to hold the throttle wide open when you run a compression test.
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