ninjette.org - View Single Post - Sanity check before potentially replacing rings on a race bike

DannoXYZ · March 16th, 2020, 08:37 PM

Compression is perfectly fine. Bleed-valve is way up by gauge, entire volume of hose is considered part of combustion-chamber. Reading of 145psi is perfectly fine.

My race 250 bike has 5 hard seasons on it now. Two by previous owner and 3 by me. It got 145psi when I picked it up. Did 40-48 days at track each year. About 10-14 of those are races, which are actually easier on bike due to less time on track. Rest are full trackdays, 2.5-3hrs at WOT. After last season, I did tune-up for this year and tested compression. Exact same 145psi.

You'll find after re-ringing engine, readings will be pretty much close to same. Perhaps even lower before it's broken in.

March 16th, 2020, 08:37 PM	#39
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Compression is perfectly fine. Bleed-valve is way up by gauge, entire volume of hose is considered part of combustion-chamber. Reading of 145psi is perfectly fine. My race 250 bike has 5 hard seasons on it now. Two by previous owner and 3 by me. It got 145psi when I picked it up. Did 40-48 days at track each year. About 10-14 of those are races, which are actually easier on bike due to less time on track. Rest are full trackdays, 2.5-3hrs at WOT. After last season, I did tune-up for this year and tested compression. Exact same 145psi. You'll find after re-ringing engine, readings will be pretty much close to same. Perhaps even lower before it's broken in.