The turbo ran great for ninety percent of the day. Then it started blowing oil out the blowby tube and the seal at the sprocket. Any other possibilities other than rings. It still runs fine but lost alot of power. Any one know of a good aftermarket forged 9/1 piston. Stock bore??Any one have any other ideas what else it might be. I am opening it up on monday?

justin

 

sounds like you broke a piston ring. this is not uncommon when trying to use a stock piston. you might need to increase your ring end gap if using a stock piston.

with my JE piston, I've had to increase my ring end gap also due to "unexplained" marks showing up on cylinder wall. I'm setting it at around 0.022" now.

also, you might have been too lean.

there is an 8:1 JE forged dish piston available lighter than stock but stronger. it's not a production item so 4 need to be ordered at a time. i ran out of the 4 I had. if there is enough interest we can order 4 more. 8:1 allows more boost to be run without detonation issues.

 

If anything I was a little rich. How much are the JE pistons. Where did ya get them??I would take at least one of them.

justin

 

it has been a while since i ordered the last set. assuming the prices haven't changed much, the total price divided by 4 is around $200, so not very expensive. i order them direct from JE.

 

I run my ring gaps @ .024" but I'm going to set my next ones up at .028" -big heat build up is definately an issue on the long hills and might have been a contributing factor to losing my motor. When we set up the TVI turbo bike we gapped the rings around .034".

 

I didn't change the boostat all (7lbs). I was getting low on gas going up a shorter hill the day before. I thought it was lean so I richened it up. It did the same thing. It was only doing it on hills cause' the slope of the hill forced the gas to the back of the tank. It did not overheat at all that day and I only ran it two or three times up a 10 second hill. When I got to st anthony it overheated on the first hill and blew a little oil. I richened it even though it was not acting lean. It had good power and ran well for several hours. It was blowing alittle oil the whole time. Then it got worse. I should have listened to a couple of others who said the piston was going to be a weak spot. Any other recommendations on the piston type?? Is scooby's piston the one to go with. By the way, I need to get htis together by friday if possible and I am swithing over to alcohol. Does anyone have a stock compression aftermarket piston in the garage.

Scooby,

kelly at KMS may be interested in a piston or two. I think he should probably start recommending people change the piston when going to the turbo.

 

It's a bad idea to let tank get low on a fuel injected bike. The pump may get starved of fuel.

I put a 5 gallon tank on and top off when it's half empty.

 

How many of the pistons would you want?? What is the part number or size piston exactly from JE? I have the larger tank already.

 

Has nayone tried the gapless 2nd ring from RW. Is there anyway to buy a single piston from JE?? I read alot about JE pistons being bought by ds guys one at a time. Are these different from the JE piston you (scooby) are talking about.

 

You need to check with scooby on the piston he's talking about.