| Author | Message | ||
     Sarodude |
Not really Buell oriented question here... I'm helping my cousin try to do something that maybe he shouldn't be attempting. He's trying to rebuild a crank from a Rotax 700 (?) cc 2 stroke twin from some Sea Doo. Any practical, real world suggestions on how to true this thing when it's all together? I mean, we've got a lathe and can easily mount the crank between centers on the lathe. My concern is more with regard to the actual truing operation of wailing on the thing with a mallet of some sort - and maybe some other stuff we don't know or haven't been concerned enough with. I've even heard of using a press to TRUE it (not just assemble it) instead of hitting it with a hammer - but I'd also heard of Santa Claus as a kid and that didn't work out so good. HELP! -Saro | ||
| Signguyxb12  |
i'am a Rotax man myself I personally would never try truing a crank without the proper tools. From what i'am told you need to heat the crank, bend it and regrind it, and then re-temper it?? No expert just repeating ehat was told to me I had a bent crank and the crank was pressed together.. swapped out the bad half... | ||
| Hoser  |
Saro : Mount the crank between centers and indicate high / low spots ,mark with a felt pen , remove the crank from the truing stand to "tweak" it , DO NOT ! wail on the crank when it is in the truing stand ( lathe in your case ). Look in the Buell factory service manual and review the techniques used to bring a crankshaft into a trued condition , to correct a " pinch" use wedges ( chisels ) , to correct a "shift" a soft hammer or a press can be used. Keep going back to the truing stand to check your progress , making fresh marks with a felt pen after indicating high / low spots .You will know you are making progress when the marks start getting close to each other when checking with an indicator and re-marking . To make efficient use of your time , be methodical , thinking about every move you make before you make it , it takes practice . I see no reason why you guys can't pull this off . | ||
| Wyckedflesh  |
I know of someone rolling the crank along a sheet of glass to find the high and low spots. I don't have the link anymore but its on the Sportster.org in their tech section where the guy built the 1425cc sporty. | ||
| Rick_a  |
I've trued a couple multi-piece cranks. Not too tough once you get a feel for how much force to put behind your blows to get the desired movement. Piece of cake with a truing stand. | ||
| Sarodude |
SignGuy- What I'm talking about doing is getting the pieces aligned after you put 'em together - not bending metal. A 2 stroke 700cc Rotax twin on a bike.... That's a nice idea.... Everyone- Thanks for the input. It's pretty much what we've known but I was just wondering if there was any strange secret that might creep out. I'll keep everyone posted on how things turn out. -Saro | ||
| Signguyxb12 |
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