[banshee217]

Last time at the track, bike ran well. I red-lit first round so loaded it on the trailer and drove it home. It sat for two weeks. Went to get it out yesterday, kicked my guts out trying to get it started. Found I was getting no spark and eventually tore it down far enough to find my crank split in two at the main pin. Never showed signs before or while trying to kick it of being locked up.
Anyone ever hear of anything this before? This is about a 10 year old Port Magic 7 mill crank. Never had an issue before. Also, anyone have a ballpark of what it would cost to have it pressed, reparied, trued and welded to get back on the track? I haven't had a chance to call Rudy yet to ask him, but I think he farmed his cranks out to Louie at Twister anyway. I could be wrong.
The center pin looks like it just sheared. Not a clean brake, but not quite a twist either. More of a fragmented break.

 

[koolguyson]

QUOTE (banshee217 @ Sep 8 2008, 12:48 PM) index.php?act=findpost&pid=10272Last time at the track, bike ran well. I red-lit first round so loaded it on the trailer and drove it home. It sat for two weeks. Went to get it out yesterday, kicked my guts out trying to get it started. Found I was getting no spark and eventually tore it down far enough to find my crank split in two at the main pin. Never showed signs before or while trying to kick it of being locked up.
Anyone ever hear of anything this before? This is about a 10 year old Port Magic 7 mill crank. Never had an issue before. Also, anyone have a ballpark of what it would cost to have it pressed, reparied, trued and welded to get back on the track? I haven't had a chance to call Rudy yet to ask him, but I think he farmed his cranks out to Louie at Twister anyway. I could be wrong.
The center pin looks like it just sheared. Not a clean brake, but not quite a twist either. More of a fragmented break.

You can go to the crankworks website and they give a pretty decent breakdown of the costs for specific labor done. Being that the crank is 10 years old, I would strongly recommend a rebuild kit as well.

 

[dajogejr]

I agree with Kool.
10 years on a crank is a LONG time...and if it's lasted this long, you're doing something right! Freshen it up...ride it another 10 years...LOL.

 

[koolguyson]

QUOTE (dajogejr @ Sep 9 2008, 04:11 AM) index.php?act=findpost&pid=10347I agree with Kool.
10 years on a crank is a LONG time...and if it's lasted this long, you're doing something right! Freshen it up...ride it another 10 years...LOL.

I was going to mention to him to shift it out of first gear but I thought that was mean. Haha. Yeah, 10 years is an incredibly long time on a crankshaft. You are ususally recommended to at least have it checked out every year or so if you are rarcing around on it.

 

[banshee217]

Shift out of first?? That would explain why it was always wound out and over revving.

Every time I tore it down, which was fairly often to inspect the tranny and shift forks, I'd measure the crank and it always looked good. Big end side play, rod flex, crank side play all checked out good. I guess it was just fatigued and finally let go.

So far pricing looks to be about 450+ to rebuild at crankworks or go with a new one for over a grand. So much for swapping out my stock cylinders for a DM.