2000 gti blown top end

[csmelone]

So i pulled the top end on a 2000 gti with the 717 motor and single carb. pto side was 135 and mag side was 80. The motor turned over fine before hand. The piston on the mag side definitely looks like it dry seized. The grey tempo lines were also still on it and I believe the motor was an sbt rebuild. I am about to order a new top end with new jugs but I don't want to toss it on and have the top end blow again. Is it safe to say the grey tempo lines caused this or is there another issue I need to fix? I'm just curious why only one cylinder ran dry and if its carb related, even on a single carb motor. I could understand if it was a dual carb. Otherwise, the ski is very clean and looks to be very well taken care of.

 

[mikidymac]

Could be just lesser quality of SBT. With a single carb as you said one cylinder can’t run leaner unless the oil line is broken or there’s an air leak. If you do a top end only I would very fuel system and carb just to be safe a for sure leak down test on the engine.

 

[csmelone]

Could be just lesser quality of SBT. With a single carb as you said one cylinder can’t run leaner unless the oil line is broken or there’s an air leak. If you do a top end only I would very fuel system and carb just to be safe a for sure leak down test on the engine.

Im sorry I didn't catch that last bit. I will definitely be replacing fuel lines and rebuilding the carb. Gonna need to pick up a leak down tester

 

[mikidymac]

IF one cylinder was running lean on a single carb engine then there was either an air leak like a crank seal or something lettina air in so there would be less fuel. The other possibility was that cylinder was not getting oil from a broken oil injection line as the little 3/32" lines are known to get old and break.

 

[csmelone]

IF one cylinder was running lean on a single carb engine then there was either an air leak like a crank seal or something lettina air in so there would be less fuel. The other possibility was that cylinder was not getting oil from a broken oil injection line as the little 3/32" lines are known to get old and break.

fingers crossed its an oil line. thank you

 

[csmelone]

the oil line looks fine. Can't find any cracks. Can they get clogged at all?