Detuning XR218 for durability ? Old School Al ?

After five years of racing my my BBR framed Powroll 220 kitted XR, I've decided that I'm getting tired of rebuilding the transmission every second year, so I'm going to put her out to pasture for the wife and kids to ride. Don't get me wrong I love this little bike and it won me some races in the vet classes against bikes with three times the horsepower, but it has its limitations. What I want to know is the availability of a lower compression piston (66.5mm I think) so it will be easier to start and more reliable. I've had the starting issues and had to replace the starter gears and it also is doesn't like to fire up when it's really hot. I'm thinking that lowering the compression would help these issues the most. If anyone knows if this product is available let me know.


What does it have now??? The 12:1 piston or the stock compression piston? You can go back to stock piston compression Wiseco piston, two base gaskets, stock cam, sell your stroker crank and get a stock crank. Basically, just put the motor back to stock. I got tired of rebuilding my race 200 motor too. I just sold mine and got a a xr100 again.

BBR uses a 5 speed ATC 200 motor rather than the 6 speed XR 200 to help with reliabilty

Not sure what you have in it now, but I assume a high comp piston of 12:1 or so and a top end cam...........?

First I'd put in a piston of about 10:1-10.5-1. Powroll has one or maybe a Wiseco, not sure what ratio the Wiseco is.

Next get the Powroll torque cam and to run with the stroked crank that you already have. They compliment each other and deliver lots of nice smooth power on the bottom and mid range. Be sure and run the auto decompressor! Starts and idles just as well as stock. Powroll did their homework on this combo, you don't have to rev like a stocker. Much easier to ride and also easier on the engine. Not a top end mx engine , but for the wife and kids with basic riding skills would be great. Put it together correctly, take care of it and it will be VERY reliable! :thumbsup:

Old School Al

If you go to a smaller carb, that will create more drag on the intake side, thus limiting the quick revving that strains the tranny.

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