Crankshaft side to side play

[kaneto]

I just noticed (I havent tried before) that when I pull on the small gear on the clutch side the crankshaft moves about 3 or 4 mm (0.1-0.15 inch). Is that normal? It's a 66cc 2-stroke on it's third tank of gas. There isn't any noticeable play up and down, just along the axis of the crank.

 

[Greg58]

It may Have been that way all along, some movement is not a problem. I would keep an eye on it just to make sure it doesn't increase. I have one engine that has too much play to my liking, I rebuilt the lower end and reused the crankshaft, installed new bearings and seals. After a couple of rides I noticed the side to side travel, I'm going to add brass or copper shims to each side to eliminate most of it. Mine is a lot worse than yours.

 

[crassius]

yes, I sometimes find a shim or two in there from the factory, but still a bit of play - never seen it cause a problem - I'd guess that when running, the bevel gear gives it some force to one side which holds it steady