The importance of a correctly sized main jet

[ollyc98]

I had a bored out engine and aftermarket exhaust but the person the fitted them didn't re-jet the carb as I found out yesterday.

I was cruising along full throttle in 4th at about 9000rpm when I had a sudden loss of power, my boots were covered in oil and water. I rolled to the side of the road, checked everything out, the engine wasn't seized but there was no compression. I thought it was the headgasket but after pushing it 2.5 miles home and stripping it down I found I had melted the piston, spark plug and metal headgasket. At least it didn't seize cos that would've chucked me off and at 70mph that would not have been fun.

 

[Manny]

lucky you then. be carefull 2 wheelers are dangerous.

 

[pjg1979]

You wre very lucky. Is it an easy job to fix olly?

 

[ollyc98]

Yeah, I can do it in about 20mins, just need to take the head and barrel off, remove the circlip, pull the pin, swap the piston over, oil the barrel, rings on the piston, drop barrel on, bolt together, new gaskets all round and job done. 8 bolts in total.

Sadly I don't have the £55 for the parts so have no choice but to sell it.