Stuck/damaged piston rings or Valve seals. 6th gen.

I have to keep riding it as it is my only form of transportation so I will keep it gentle and top the oil up regularly. As for contamination there is none of that, I have been checking that and the oil is milk free and the coolant is still blue.

Every time I start it I have to remind myself that it is partially broken because it sounds fine and everyone that I ride with said listening to it you would never know. If I stay below 6k, which is pretty easy with all the low down torque, riding is fine and oil burning is minimal. I have checked the oil for metal bits and found none.

The replacement engine should be delivered by end of this month/start of next and the tear down and swap should take a weekend.

I expect the walls of piston #4 to be scarred or have some comically improperly installed rings and in either case the cylinder will need reboring. I was thinking I would order a brand new set of .25 OS CBR929 pistons/rings/pins from honda which would give me 837cc~. Don't ask why, it just strikes my fancy. Will make a thread when the teardown and buildup begins. Once that is done I will put it right back into the bike but I have no idea what to do with the temporary used engine... Probably just do a complete rebuild as well and have it as a backup.

 

Can't believe I did this... I go to put some more cleaner in the cylinder one last time before I call it quits only to watch it all drain out the drain port... I completely forgot about that last time so no cleaner ever got into the cylinder I bet. Gonna go all weekend with more cleaner and let it really soak in then I will ride it for a little while and change the oil. I don't expect miracles but ya never know.

 

I wish you lot of luck there boss. It is sad to see a low mileage bike having engine trouble :sad:

 

Well after two days of soaking in Marvel Mystery Oil I can say there is less smoke under hard throttle but it is still there. I will try this once more over my next two day break and this time lift the front of the bike so I get full coverage, though the fact that I turned the engine over with compression should have forced the MMO around the whole cylinder. I am happy there is less smoke but still there is an issue.

I know the MMO got into the cylinder cause the bike smoked like a chimney for a good 15 minutes until it all burned out so at least I got that right this time!!!

update: went for a good ride, bike seems to run better but is still burning oil so I have to assume it's the placebo affect.

 

i know this is an old thread sounds similar to my symptoms 16000 miles 6th gen could you tell us all the outcome (new engine and/or the damage to the original. Many thanks Stubbsy

 

I had similar symptoms on my Ducati Monster. Although, head gasket was much more obvious due to the fact oil was leaking from the lower side of it outside and inside the cylinder. It just needed a new head gasket, and that's not that hard to do. I'm actually doing that on a kawasaki Concours atm.

 

Yeah prob i have is theres no sign of any oil leaks whatsever. Oil level dips but i have intermitent smoking, just thinking the last owner overfilled the oil and im thinking the breather pipe maybe blocked? / dont know for sure but read theres a drain plug on the breather pipe,defo blue smoke as coolant level all good.No smoke on start up / just every now again .

 

Do a compression test like was mentioned a long while back in this thread. Measuring crank case pressure isn't an easy thing to do. If you get shit compression, do a leak down test. That will tell you roughly where your oil in the cylinder is coming from.

 

Will do im taking it to a very competent guy who i know who will hopefully get the prop diagnosed and ill go from there.