hi guys i have a yamaha dt 100 just restored i bored the engine change gaskets and seals it strats imediately but there is a ticking noise tick tick tick tick tick taught its the small end bearing change it but still that noise is there any ideas cos im without them now this bike drives me crazy

Hey there , 

so from what I’ve read (as I have the same sound in my RT3) , it could be a few things.

It could be a bit of piston slap , which is caused by the piston now being undersized after you’ve had the cylinder bored. It won’t hurt anything from what I’ve read, but it is pretty annoying! Have you measured your clearance after the bore? 

Another thing it could be is the wrist pin bearing that goes inside the piston, that could be kaput and in need of a replacement. 

Another thing , it could be the
bearing inside the crank that’s needing a replacement. 




 

the bore was measured on the piston so the clearance is good the pin that goes in piston is new came with the piston kit and the small connecting rod bearing is new also the main thing im thinking is the big connecting rod bearing i mean the crank bearing but i have to open the whole engine and not worthit

Check that your exhaust is hooked up solid with a new gasket. I’ve had weird engine noises turn out to be nothing more than exhaust that needed attention.

Your bike looks so nice. Saw the pics on your other post. Could the noise be a head gasket not clearing the bore so getting tapped by the piston. Highly unlikely i know. Is it a regular noise in time with the revs if you go up & down from idle. We love videos, or good audio in this case. Hope it was bored to about the correct clearance which will be only about 0.045mm clearance or close to 1.8 thou. Does sound like piston clearance from your description if there's nothing else obvious.