please help a new guy

[exrider84]

hello folks, I just picked up a 86 model that need crank and cylinder replaced, yain question is, I'm a woods rider, fast paced, what would be the best direction to go as far as building the motor, any and all help is much appreciated and thank you.

[deadly]

Basically you do GNCC style riding then huh?
You don't need anything elaborate. Many racers that still use the R have a 300 or 310 kit. This way you don't need to bore the cases. Anything above 75mm needs the cases to be bored (technically 75mm is too close for my comfort but will work) and either of these two aforementioned kits won't need any modification other than rejetting and I (maybe?) longer cylinder bolts. On race gas (110) you can hit 54HP fairly easy and the stock radiator works just fine. But that's something you need to decide if you want to run race gas or not.

When you buy it ensure you tell the builder what kind of riding you do so they can port it appropriately. (in no particular order) C-Leigh on this forum does work as well as LED Performance Engines is also a great one. Don't forget about the pipe. You'll want something that excels in low and mid range. The LRD Team B is an excellent pipe IMHO. There's plenty to choose from but some pipes are just "pipey" and really suck on the bottom but explode on the midrange. Smooth usable power delivery is where it's at

[exrider84]

thanks for the quick reply, I'd like to stay with pump gas, is there any brand piston that is better than the others? I'll have more info as to what kind of pipe and carb are on the bike tomorrow evening when I got more time to go over the bike

[acecarlos]

One or two good options are to Pro Port & Flow your cylinder, you don't need a 310 kit to make 52 HP, a well set-up, Ported & Flowed OEM cylinder will hit those numbers, plus a good pipe like a Paul Turner or TRX5 (I would not use the LRD pipe), good set of reeds, 36MM Keihin carb, and your good to go.

Best pistons on the market as far as quality go are the Wossner's specially in sizes from 66MM-68MM, followed by Wiseco's...both excellent choices.

Carlos.

[exrider84]

upon futher inspection I have found that the center cases have been busted, how bad? I don't know. I have not split the motor open yet. is there a chance that I could still use them? I know I can't get no anwser without a decent pic if it, just shootin in the dark here

[acecarlos]

99% of the cases we see that are damaged can be repaired, some take a lot of work, while others requiere simple fixes. If the repair is extensive, finding a good used right or left center case is the best option. Pictures would help...

Carlos.