120 PSI compression OK?
120 PSI compression OK?
I bought a 93' CR 500 back in Feb and it has ran well for me the 2 or 3 times I took it out to Dumont. The guy I bought it off of said he and his dad rebuilt the top end recently before I purchased it. I don't know what bore it's on I haven't looked but I think stock. I put on a PC pipe, Boyesen Rad valve and the rest of the motor is stock.
Anyway I checked my compression and it's at 120. I looked through the exhaust port and I noticed some scoring. Should I just ride until the compression get's lower or should I rebuild now? If I do rebuild I think I am sending the cylinder to GSS for porting.
Grey
Anyway I checked my compression and it's at 120. I looked through the exhaust port and I noticed some scoring. Should I just ride until the compression get's lower or should I rebuild now? If I do rebuild I think I am sending the cylinder to GSS for porting.
Grey
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i would ride it atleast until winter, maybe even next summer also. mine is 100psi and runs fine but im also at 6,500'...i heard you lose 5psi for every 1,000' above sea level, (my compression gauge might be fucked too though). i would be more concearned with how loose the piston is, especially if you have the stock piston still in there.
- iggys-amsoil
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- Location: Just North of March Airfield CA
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ya them scratches will cause a major explosion ! sleeve will crack and piston will grenade into 5000 pieces, then the crank will spit them out the head and they will lodge in your nutz, causing you to crash into a tree
. brit puts his bike through more abuse than all of us put together and its still running fine. some tiny scratches aint going to bring down the mighty CR500 


Im lucky to get triple digits EVER with mine. I dont weigh enough to kick it fast enough. 120 is plenty, but fragging a piston is a possible total loss minus the trans...If the bike is vibing abnormally id at least tear down and inspect the top end...
Faster then Speedy Gonzalez, slower then the Road Runner!!! MEEP MEEP
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
2002 CR80
1999 Cr500
2003 CR250R
2005 CRF250R
2006 YZ450F
2005 CBR1000RR
1997 Banshee
- NightBiker07
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rebuild ASAP. ignoring it can make deeper gouges, creating more problems. not to mention, you dont know how old the top end actually is.
2000 CR250, pipe, filter, Vforce
1980 XL80s
1969 Broncco TX-6
Natural selection favors Smart people, so nature selects morons to be slow and dumb for tigers and stuff too eat. But in our modern world there just aren't enough tigers.
1980 XL80s
1969 Broncco TX-6
Natural selection favors Smart people, so nature selects morons to be slow and dumb for tigers and stuff too eat. But in our modern world there just aren't enough tigers.