Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties balancing flywheels

balancing flywheels

Moderators: Curt!, Pa

Post Thu Dec 16, 1999 3:23 am

Posts: 582
Location: meridian, id. usa
Well Matty dont mean to be cute, but how often do you want your fillings replaced at the dentist

Post Thu Dec 16, 1999 3:31 am
don User avatar

Posts: 571
Location: Spokane WA USA
It should be noted that original wheel sets were factory balanced for midrange oversize pistons {+.035}

Post Thu Dec 16, 1999 3:43 am

Posts: 540
Location: Kansas City, Mo USofA
If you've done much to the stocker (lighter pistons...etc.) you probably ought to do it, I ran a 40 UL that was .060 and never balenced it. I never ran enough R's to matter? I always worried that I should have but the consencious opinion in them days was you wern't gonna get it much better (we used lathe centers)

Post Thu Dec 16, 1999 3:46 am

Posts: 540
Location: Kansas City, Mo USofA
Just in case you (like myself) is trying to figgure out just what in the hell I just said. . . I wouldn't worry too much about it if you stayed under +.030 and didn't go to a lighter piston.

Post Thu Dec 16, 1999 4:18 am

Posts: 3011
Location: Central Illinois, USA
I have been studying (and performing it as a service)balancing for some time, and I am convinced that if you are only dealing with a common overhaul, then it amounts to a fart in a hailstorm. Balancing on a V-twin is more of a performance tuning technique than anything to do with feelable vibrations. Accurate trueing of the crank is what is paramount. If you play with creative motorbuilding, then you probably have a handle on the phenomenon anyway. For normal service, the factory formula serves us well...Cotten

Post Sun Dec 19, 1999 3:47 am

Posts: 37
Location: tucson az usa
i think flywheel balanceing is done for a specific rpm range , low cuise might be 2500 rpm , or higher at 3500 rpm, then there flat out race 5000 rpm . set the balance where the motor will work the hardest.according to your style of riding, of couse one size fit all mentallity will work OK . but for reliveing the strain the the engine and drive train , reduce all vibrations,

Post Mon Dec 20, 1999 6:00 am

Posts: 54
Location: cumberland WI USA
I'm about to do a balance job on a HD 45 and i've heard that with the short stroke of the 45 that you should use a smaller factor of the resecption weight any where from 50% to 60% I invite all to give me there oppion will be boring out to .070 over and will run a 33 tooth motor sprocked and wouln like to be able to cruse 65 or so Thank You FLATRAT

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