Why you say i am running lean. Thought the piston wash was from running rich as in undetonated fuel washing the piston head.
Ski runs fine on trailer but not in water.
- Thread starter shank
- Start date
Why you say i am running lean. Thought the piston wash was from running rich as in undetonated fuel washing the piston head.
Anyway here is the problem. rings gone mostly and scoring on rear piston. see pics. also top of piston worn on edges looks like from combustion.
I am not sure if its from piston seizing or from detonation. I was thinking because my flywheel and stator where so dirty maybe the timing got thronn off and it detonated early. not sure what else would cause detonation. If seizure not sure how at moment. Motor did get flooded with water due to a major hull leak causing it to fill up. i got motor running again a couple hours later. seemed fine at the time. the water leak is fixed now.
I am already at max bore 1.0 over pistons. I am thinking maybe just hone cyl and new rings and piston. ant do much about the scoring on the cylinders as i cant bore for bigger pistons.
I am not sure if its from piston seizing or from detonation. I was thinking because my flywheel and stator where so dirty maybe the timing got thronn off and it detonated early. not sure what else would cause detonation. If seizure not sure how at moment. Motor did get flooded with water due to a major hull leak causing it to fill up. i got motor running again a couple hours later. seemed fine at the time. the water leak is fixed now.
I am already at max bore 1.0 over pistons. I am thinking maybe just hone cyl and new rings and piston. ant do much about the scoring on the cylinders as i cant bore for bigger pistons.
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john zigler
Vendor Account
- Location
- wisconsin
More fuel (Rich) will "wash" more carbon off the piston tops.
Running lean will create heat, which can and will lead to detonation.
Sorry, but there is no way you are still in spec and be able to just hone that cyl.
Are u saying because of more carbon on rear cylinder it was imdicates running lean and caused detonation via heat.
Wierd as both carbs rebuilt not that long ago. After water got in motor i cleaned both carbs out. Both carbs had same screw settings for hi and lo.
I will have to check cyl specs as i cant bore. Dont think they make sxr cyl any more to get new one.
Quinc
Buy a Superjet
- Location
- California
You can bore those out to 84mm.
john zigler
Vendor Account
- Location
- wisconsin
Lean condition can be from many things, bad/dirty/out of spec carbs, air leak, etc. may very well be you have bad crank seals.
john zigler
Vendor Account
- Location
- wisconsin
This is a Kaw SXR 800. Even though Wiseco does list big pin Kaw "750" pistons up to 84mm, I would definitely not recommend running them with out big bore sleeves. Kawi's run hot as is, and the stock sleeves will be very thin. Not to mention standard Wiseco Piston issues....
Shank, look for agood used, standard bore cyl. They are out there.....
Quinc
Buy a Superjet
- Location
- California
My bad I thought we where talking about an SJ.
Havnt seen pistons over plus 1.0mm. I will look harder
Ill research it
yeh i posted in the wrong forum.
john zigler
Vendor Account
- Location
- wisconsin
Big Pin Kaw 750 cases will interchange.
john zigler
Vendor Account
- Location
- wisconsin
Reed my post above. You can NOT just run 84mm pistons..... You really need to find a good used cly, or have yours resleeved (Which is costly)
- Location
- Long Beach, CA
take the fish out of the intake
