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120 PSI compression OK?
Posted: July 19th, 2009, 4:50 pm
by greylynn
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
Posted: July 19th, 2009, 6:34 pm
by 100hp honda
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.
Posted: July 19th, 2009, 7:32 pm
by lewisclan
ride it
Posted: July 19th, 2009, 9:10 pm
by iggys-amsoil
The rebuilt top end was to sell it, since you see score marks plan on a new top end NOW.
Posted: July 19th, 2009, 10:22 pm
by 100hp honda
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
Posted: July 19th, 2009, 11:47 pm
by greylynn
It's gonna get run a few more times before I rebuild it then. I'm gonna just order all the parts from service Honda when I rebuild it. Thanks for the input guys.
Grey
Posted: July 21st, 2009, 8:05 pm
by M.F.D.B.
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...
Posted: August 9th, 2009, 9:53 pm
by NightBiker07
rebuild ASAP. ignoring it can make deeper gouges, creating more problems. not to mention, you dont know how old the top end actually is.
Posted: August 9th, 2009, 10:36 pm
by AlisoBob
Like Jay says.....
Run it
Posted: August 10th, 2009, 8:17 am
by M.F.D.B.
AlisoBob wrote:Like Jay says.....
Run it
x2