06-09-2017, 05:10 AM
I bought an axle from BMI Karts for my Rupp. After I got it all together and fired it up I could see the engine move up and down following the axle. Took it all back apart, screwed the nuts on each end and set those in V-blocks clamped to a steel work bench. Then I set up a magnetic base dial indicator to check run-out along the length of it. Not the best way to do it, but it's what I had available to me. I found the axle had .048" run-out at it's worst point. After several attempts in the press I got down to .010" at it's worst, only problem is that's right where the bearing runs. Oh well, it's better than it was. As was suggested by another poster, I put that end opposite the sprocket and live with it. I'm sure those Chinese tires run out a lot worse than that. The engine is still now and I don't notice it driving, that's close enough for me.