I was wondering what compression should be at when the engine is cold and when it is warmed up. Everyone says 120psi, but how much below that is acceptable?
I have an Elite LX engine and it is only registering at 60psi. I'm not sure how tight I have to get the hose to get a good reading? I'm going to check the reeds next, if they are ok I guess it is time for a ring job.
Compression Check
Moderator: Moderator
- bradthreee
- Board Supporter
- Posts: 2142
- Joined: Tue Sep 12, 2006 4:20 pm
- Location: MARS...
- Wheelman-111
- Moderator
- Posts: 11325
- Joined: Wed Oct 22, 2008 5:09 pm
- Location: Deepinnaharta, Texas
Tester Tightness Tip
Greetings:
The compression tester fitting has to be completely airtight in the plug hole. Any reading is useless without that.
The compression tester fitting has to be completely airtight in the plug hole. Any reading is useless without that.
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
Thanks Wheelman, of WHAC. How do you get the fitting airtight? It is hard enough for me just to get the sparkplug out in that tight space (my hands have possibly grown since I was 15). I purchased the cheap compression tester from Harbor Freight. I disconnect the gauge and basically just twist it in as tight as I can using the tube. Any suggestions?
- wikked_spree57
- Elite
- Posts: 980
- Joined: Thu Aug 16, 2007 6:50 am
- Location: Bridgeport, MI
- Contact:
teeoce, tightening it like you did should be good. Maybe you could rent a tester from Autozone or other auto store (Possible better quality). Are you using electric start and wide open throttle when testing? If not, try that.
2001 Honda Elite
1995 Yamaha Jog
1994 Yamaha Axis
I can't believe
that cop put me
in the backseat
when I clearly
called shotgun.
1995 Yamaha Jog
1994 Yamaha Axis
I can't believe
that cop put me
in the backseat
when I clearly
called shotgun.
- burnt_toast
- Veteran OG
- Posts: 3592
- Joined: Sat Jul 31, 2004 8:00 pm
- Location: Atlanta, GA