503 hp??

[off road rider]

looking for a little bit more poop out of a 503. Anyone here actually build one?,
(First hand knowledge).. without changing motors?.. Theres got to be alot that can be done with the little fanner

 

[x2468]

hey i just posted in ur TT thread. when did you get a hawk? that's cool. do you still have the 2moto?

 

[off road rider]

hey i just posted in ur TT thread. when did you get a hawk? that's cool. do you still have the 2moto?

Still have the 2moto, a guys got to have more than one snowtoy, although they are sim. type of machines they each have strong points in different riding conditions or areas.

 

[TLKDPROD]

I'd say clutching, then head shave.

looking for a little bit more poop out of a 503. Anyone here actually build one?, (First hand knowledge).. without changing motors?.. Theres got to be alot that can be done with the little fanner

I think the biggest performance gains you can get out of a 503 is with a good clutching setup. Ozzydog has been hammering on this problem all winter long apparently, I tried to find the thread back but so far no luck. P-85 primary with A-Cat secondary is the way to go apparently. Exact setup of each one still unknown from "the public" !

If you soup the engine up too much, you may get overheating problems.
But shaving the head a few thow won't hurt her too much I think ! If I remember well, I think the squish on the 503 I got was around .075" (check just to make sure). I've been told by my tuner back east that going down to .065" would still be plenty safe. Isn't there something on the domes/head of a 503 that makes it harder to shave ? Like a part of the dome fits the inside of the cylinders ? Anyway, there has to be a simple way to do it like decking you cylinders down... and if you ride high up Baker often, it would sure be good to have a bit higher compression ratio to "compensate" for the altitude.

That's what I'd do first after jetting it right !

 

[off road rider]

Thanks for the info TLK. I dont know anything about the head conf. on the little Rotax. I figure basic hop up skills from the dirtbikes and muscle cars will liven it up a bit, Then the NOS will help with the bigger hills.
Shes jetted spot on thanks to info from TonyHawk.. a few tweeks to the stock clutching where working fairly good, but this summer will see something hopefully better..Ignition info would be great..