Hi all I've recently had a rebore, new piston and rings,small end bearing head gaskit etc all done by professional .The problem I have now is that my engine sounds a bit rough, it was run in correctly and goes really well now(800 miles since rebore).The sound is mainly when comming off the throttle, meaning when slowing down its like gadung gudung gudung rattle rattle type sound rather than being a smooth slowing down type thing. The sound isn't there when the engine is cold, soon as I'm up to normal temp there it is!! Tit seems to come from the left hand crank case side looking forward on the bike.Ive had the crank cover off and doesn't seem much play in the flywheel at all. I've heard before that after a rebore it stuffs up the small end bearing , no idea if this is true! Part of me thinks it sounds like the piston clattering up and down as I slow, I'm just not sure, could it be the power valve ? Piston or rings?big end ?? Any ideas would be good Thanks
I would have the top off an have a look. Best and only way of checking for sure. Sounds to me like a ring might have gone. IMF you read in the Haynes manual they have a fault diagnosis section at the start and I think a metallic rattle when coming off the throttle oils mean a ring having broken. For the cost of he gaskets it's worth checking IMO.
Well that's a greener. Personally I would never pay anyone to do work on my bike. When you reborn the cylinder you're suppose to soften the burrs down on the ports. Else the rings catch and snap on the ports. If that happens you'll end up with rings I the bottom end and hello full engine rebuild!
Fml mate if that's the case I'd be round there in a shot!
Do u know what size it was bored to as it could be hitting the power valve closing ,before you take the top off have a look up the exhaust port,and chuck a pic up so can see up th port into the cylinder
