- Fri Mar 30, 2018 6:48 am
#8233
Hi everyone, My 350cc clipper is blowing smoke. After starting the bike it does not smoke straight away it starts after about 40 seconds then as I increase the revs so the smoke increases it then continues to smoke, the amount depends on the revs. The exhaust pipe has blackened oil at the pipe entry, after running for five minutes I can see slight drops of "blackened' oil dripping where the pipe enters the head. The plug is also oiled up as is the exhaust port.
I have done the following: (with parts from H) replaced the valve stems and valves, (fitted by an engine reconditioner), these were very worn. The exhaust rockers were worn so that at higher revs, oil was being sprayed onto the exhaust valve so these have also been replaced. The compresion is good and the piston ring gaps, when inserted in bore, were well in tolerance, I did observe that the Top ring was a 'chrome' type, the 2nd ring and scraper were 'normal' and the 'top' mark on the 2nd ring was correct. I have just ordered a new set of rings from Hitchcocks just in case. I also removed the 'Breather' pipe and could sense air being expelled so I assume the engine is breathing. Prior to starting I drained the sump in case the smoking was due to 'wet sumping'.
Any comments would be appreciated. Thanks.
I have done the following: (with parts from H) replaced the valve stems and valves, (fitted by an engine reconditioner), these were very worn. The exhaust rockers were worn so that at higher revs, oil was being sprayed onto the exhaust valve so these have also been replaced. The compresion is good and the piston ring gaps, when inserted in bore, were well in tolerance, I did observe that the Top ring was a 'chrome' type, the 2nd ring and scraper were 'normal' and the 'top' mark on the 2nd ring was correct. I have just ordered a new set of rings from Hitchcocks just in case. I also removed the 'Breather' pipe and could sense air being expelled so I assume the engine is breathing. Prior to starting I drained the sump in case the smoking was due to 'wet sumping'.
Any comments would be appreciated. Thanks.