New here

DBJim

DBJim

I just installed a C-W Cylinder -kit, it started puffing smoke on the third heat cycle. I replaced valve seals and timing chain at the same time along with all gaskets. I have never used cycleworks products. During the installation i made sure oil rings were 1/3 spacing and the letter on compression faced up ring gap was to spec. Then used a ring compressor so it went smooth. It ran well first 2 heat cycles and on the third one puffed smpke on the throtle blip. I rode then went home. curiosity the following morning had me start it to see it it was a fluke. NOPE!

I proceeded to pull the top end. because I thought a broken cir clip. not the case. rings looked just like I installed them. unless the oil compression rings have a direction I'm at a loss as to how I made a 4 stroke into a 2 stroke.
 
DBJim

DBJim

Correct. Rode it yesterday after reassembly. It started no smoke. Rode it and the same as the third heat cycle. Puffing on quick throttle blip. I’ve rebuilt a lot of bikes. This is a first. I’ve used vertex piston’s before. Scratching my head on this one.
 
charlesthomas

charlesthomas

Most likely the oil control ring is upside down or not seating properly. That causes oil to pass into the combustion chamber, especially on throttle blips. Also check the cylinder was properly honed, if it’s too smooth, the rings won’t seal.
Reinstall with correct oil ring orientation (mark facing up) and lightly hone the cylinder before refitting.
 
Top