Engine Balancing ?

[Derrick Adams]

I wondered if the enternal rotating assembly is/should be balanced?
I was out riding the Z and it'll just about shake the fillings out of your head. Then I was riding Kryten's R and it was smooth as silk. Seem's like I read about another Z that vibrated like that too. I'm sure that's what contributed to the pipe breaking at the head.

Just wondered if the crank can be balanced or if there is other things I should check for failure.

[skippy]

what bore is yr cylinder on? how are the crank bearings?

[Derrick Adams]

Beats me. I just took delivery of it last Thursday. The guy I got it from had no idea either. It seems to run exceptionally well, and starts with 1 kick. I won't be tearing into it until it breaks or wears out, but when I do, I think I'd like to work out some of the vibration if I can.

[TimSr]

The R has a counter balancer and will have noticeably less vibration than the Z no matter what you do, so you cant use it as a comparison. If your Z, in fact, vibrates more than it naturally does or should, it can be caused by worn crank bearings, crank ashft not perfectly straight, worn lower rod bearings or a bent or out of whack flywheel, but you really need to compare it to a properly running Z to know if thats the case.

[Derrick Adams]

Well, now that makes more sense. I didn't know the R had a counter balancer.
I just couldn't get over how smooth it was.

[samster143]

I think balancing is more for multi cylinder engines to keep an even load on the crank. like balanced pistons and con rods I am not really sure if a single cyl would need any balancing. I may be wrong however.

[Curtis-Tecate3]

Balancing a single cylinder isnt really a balance per se. It it more of changing the harmonics of the motor and moving the "Happy" spot to a different location in the RPM range. There are more things like getting the crank halves perfectly lined up etc. but you get the idea. I had a crank done at Falicon (arguably the best in the country) a long time ago. I sent them my 200X crank to correct a different shops lightening screw up. What I got back was a beautiful piece of work. My full circle crank came back with a triangular shape with mallory metal welded in to balance it. Too bad I screwed it up installing the flywheel and it died 2 years later taking out the lighting coil at the same time.

Check their website.
I dont think they do singles anymore but you never know.
BTW, They are the best, not the cheapest....

http://www.faliconcranks.com

Curtis.