Is it piston rings or valve stem seals? ;/
Is it piston rings or valve stem seals? ;/
(OP)
Heeyo, i`m not quite sure what that would be. I have yzf r125 with 15k miles on.
So - it starts to smoke at certain rpm. Like 7-8k and above. As ive done the video i held the revs at 3k, nothing. 6k - nothing. Above 8k - smoked like bob marley.
As far as i know this could be valve seals? If it would definately be piston rings, it would smoke all the time? Even just a bit?
To be honest, it ate 1L of oil in 100miles. But i was riding it agressively. When i`ve noticed the smoke and lack of oil, i have topped it up, and done about 20miles since then, and the oil is still in ( i was riding it on low rpms all the time.)
Any help will be appreciated.
Heres a video that explains everything :
https://www.youtube.com/watch?v=wHkKm26Qmzo&fe...
So - it starts to smoke at certain rpm. Like 7-8k and above. As ive done the video i held the revs at 3k, nothing. 6k - nothing. Above 8k - smoked like bob marley.
As far as i know this could be valve seals? If it would definately be piston rings, it would smoke all the time? Even just a bit?
To be honest, it ate 1L of oil in 100miles. But i was riding it agressively. When i`ve noticed the smoke and lack of oil, i have topped it up, and done about 20miles since then, and the oil is still in ( i was riding it on low rpms all the time.)
Any help will be appreciated.
Heres a video that explains everything :
https://www.youtube.com/watch?v=wHkKm26Qmzo&fe...





RE: Is it piston rings or valve stem seals? ;/
Any chance there is an issue with the oil dipstick/oil level indicator?
Engines with wet sumps when over filled sometimes are very rpm sensitive, becoming very smokey when some magic rpm is reached.
RE: Is it piston rings or valve stem seals? ;/
Make sure the correct procedure was followed when checking the engine oil level. It's supposed to be done with the bike held vertically (read the owner's book - it should explain this). Checking it with the bike on the side stand will overfill it very substantially and then see above post for what happens. If the engine is overfilled, there's your problem. Drain the excess and then exit this diagnosis procedure. You might need a new air filter and a new spark plug to clear up the oil contamination.
Open the air filter housing and check for oil built up in there, especially around the area where the crankcase vent connects to it. If you have gotten to this point in this diagnosis procedure, this is not because of excess oil in the crankcase and it means there is excessive crankcase blowby. That means it needs piston rings.
Regardless of whether it's rings or valve seals, the engine has to come apart at this point. Fortunately, it's a simple engine. One cylinder, 4 valves. The condition of the engine when inspected during disassembly could very well reveal the actual problem.
RE: Is it piston rings or valve stem seals? ;/
P.S. replying to a first reply :
I have had the bike for 2weeks, bought it second hand. It has 15k miles on clock. And i dont think there is any issue with the dipstick at all. I can see and smell oil burining just going by the blue smoke. As i said - it does not overheat and does not smoke at rpm up to 8k. After 8k it starts to smoke badly. Ive heard that this particular isssue might be associated with valve stem seals?
RE: Is it piston rings or valve stem seals? ;/
RE: Is it piston rings or valve stem seals? ;/
RE: Is it piston rings or valve stem seals? ;/
RE: Is it piston rings or valve stem seals? ;/
If on the other hand the bike smokes when under high load and higher revs, the piston rings more likely are at fault. At high revs and high load piston rings may get into a vibrating mode which will lead to more oil entering the combustion chamber. the piston rings may also have worn considerably, especially when the bike has been driven in a dusty environment and maintenance of the airfilter system has been somewhat neglected.
RE: Is it piston rings or valve stem seals? ;/
RE: Is it piston rings or valve stem seals? ;/
RE: Is it piston rings or valve stem seals? ;/
RE: Is it piston rings or valve stem seals? ;/