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558M Stroker Build up

MTImodquad2010-08-09 22:26:08 +0000 #1
Well I finally got it finished. I started with an '06 500M and built it to a 558 stroker. It's not a big horse power motor that will launch off the line like a Tcat or anything. I built it to be a good reliable trail mudder. It has a ton of torque. It's kind of a tribute to the orginal Cat mudder. These 500M's are still the best mudding bike IMO. I can sit on the glove box with it in high range and it will stand straight up. That is with a 6" lift and 29.5's.

I got a hold of a 550 topend. The sleeve had to be turned down slightly to fit it into the 500 cases. It was a very small amount so it was easier to take the material away from the sleeve rather than have the cases bored. I had the crank stroked 2mm by T u r n e r C y c l e s. The stock bore and stroke of a 500 is 87.5mm X 82mm, which equals 493cc. With the stroked crank and 550 topend I know have 92mm X 84mm giving me 558cc. That is the base of my build.

I had the head port and polished by Lanny's flow service in Arkansas. He did a great job! The piston was machined to maintain close to stock compression (10.8:1). I put a 650H1 cam with a 5* offset magneto key to advance the timing. I am running E-85 Ethanol in it.

I replaced all the springs in the clutch and shift linkage while I had it apart. I never adjusted the clutch, I just bolted it all together. The thing has never shift so good, not even off the showroom floor lol.

This was a really fun bike to build. I wanted to build a machine that would trun any tire in any mud. The maunals are hard to turn into race bikes with the big lifts on them. I think this motor would be really competitive in the bogger class.

Next I am taking my spare 500M motor and putting a 650H1 topend on it that you have heard so much talk about. Then this 558 will be my back up motor lol.

Here's a couple action shots of the first weekend out on it. I wasn't cutting it any slack at all.


Yesterday2010-08-09 22:28:01 +0000 #2
I had the head port and polished by Lanny's flow service in Arkansas.

where's this guy at in arkansas?



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