maybe the ports are blocked???

I have done around 1000klms on a streetrace kit on my Aerox. Just though I would pull the cylinder off to check it all out... was running fine, just wanted to check it all out anyway.. rings etc...

So I pulled the cylinder off and am not sure what to make of the findings.

The piston is obviously still on the crank, so on the side of piston (facing up) it is all scored terribly, most on the skirt part of the piston... and so is the barrel.

The other side of the piston is in perfect condition. So one is good, the other side is very average.

Also when I took the head off. half of the combustion chamber is coked up/black.. the other half is a nice shiney chrome.

so if you were to picture the barrel and piston together.. the scored part of the piston is the same side as the nice shiney chrome side of the head...

The perfect side of the piston is the same side as the coked up/black side of the head...

Also, I don't know if its related, but oil is leaking out the plug hole and there is a dried trail of oil down the front of the head...

What should I make of all this???

 

Do you run premix or auto lube?

 

I am not running the factory oil bottle.. I premix 50:1

 

That's odd, I would've thought the problem was caused by too much oil but if anything 50:1 isn't quite enough for your setup

 

really???? What ratiio should I be running..???. I read some people run 40:1... but I wasnt that game.. so i went to 50.

 

I'd say 45:1, I run 50:1 on a 50cc (see the spec in my signature), and since the streetrace is quite high spec for a sport kit 45:1 would be safe

 

33:1 is way too much oil man, stock oil pump is 50:1

 

So why would only one side be worn... and why only half the chamber be coked up???

 

105 jet in a 19mm dellorto.... I use a br9es I think

 

haha!! My Husky is a 4 stroke... and I dont mess around with that motor!!! Dont need too!!! LOL!!

 

They have hot start ;D

Would detonation cause the problems with the cylinder?

 

I decided while it was apart to port the exhaust port on the streetrace.

It now struggles to get up my hill. going up my hill it sits on 7,000rpm... on the flat when it hits 8,000rpm it takes quick as normal. its pretty dead up until 8,000rpm now. I dropped the rollers in weight but no difference so eliminated that.

Before the porting I was running a 50 pilot jet with mixture screw turned OUT 4 times. The more I turn it IN the slighty better it gets (deosn't break down as much at 6-7,000rpm) but still not going up the hill. Just bogs down. my carb is a 19mm dellorto. Is turning it in riching it up??? or leaning it out?? And because I ported it, is it wanting more fuel??? HELP!!!

 

On most carbs turning in the mixture screw richens the mix,

 

ok so it must want a bigger pilot.... bigger than 50??? thats big!!!

 

105 size main jet