KH250 A5 Oil Leak / smoke issue
Posted: Mon Mar 18, 2024 3:53 pm
Hi folks, I've been a member for a few years but am not a regular contributor - apologies. I need the groups' expert wisdom and experience on a possible problem I have with my triple:-
symptoms - some evidence of an oil leak on right hand side of bike, under cases and along the expansion chambers. Its not coating the tyre but there is enough to be concerned. Initially I assumed that it was 2-stroke oil leaking somewhere from the old pipes, but eventually concluded that the clutch casing was leaking, and duly found little gearbox oil retained when I checked everything over and reseated the casing. There is a good amount of smoke on throttle on the right hand (offside) cylinder until the bike has run for a while and warmed up properly. As im havent run 2 strokes in my earlier years I cant decide if the on throttle puffs behind me are normal or gearbox oil being drawn in. Otherwise the bike runs very well and ticks over nicely - its a damn fine ride! Its still on the standard bore / pistons at circa 16k miles.
Initial diagnosis thoughts:- the crank end seal is either shot or not seated properly, drawing gearbox oil in on the compression stroke and blowing out of the cases on the firing stroke.
Questions
- does the diagnosis sound correct?
- any other diagnosis suggestions?
- what is the risk of running it like this (albeit keeping the gearbox oil topped up!)
- how easy is it to change the seals without taking the engine out / splitting cases? and if so any special tools needed other that pullers and picks?
- any gotchas to watch for?
thanks in advance
Mark
symptoms - some evidence of an oil leak on right hand side of bike, under cases and along the expansion chambers. Its not coating the tyre but there is enough to be concerned. Initially I assumed that it was 2-stroke oil leaking somewhere from the old pipes, but eventually concluded that the clutch casing was leaking, and duly found little gearbox oil retained when I checked everything over and reseated the casing. There is a good amount of smoke on throttle on the right hand (offside) cylinder until the bike has run for a while and warmed up properly. As im havent run 2 strokes in my earlier years I cant decide if the on throttle puffs behind me are normal or gearbox oil being drawn in. Otherwise the bike runs very well and ticks over nicely - its a damn fine ride! Its still on the standard bore / pistons at circa 16k miles.
Initial diagnosis thoughts:- the crank end seal is either shot or not seated properly, drawing gearbox oil in on the compression stroke and blowing out of the cases on the firing stroke.
Questions
- does the diagnosis sound correct?
- any other diagnosis suggestions?
- what is the risk of running it like this (albeit keeping the gearbox oil topped up!)
- how easy is it to change the seals without taking the engine out / splitting cases? and if so any special tools needed other that pullers and picks?
- any gotchas to watch for?
thanks in advance
Mark