I am new to Micro racing, but not new to racing. I was wondering what the difference is between, say a CR-250 motor or a Four Tracks 250R motor? I would assume the gearcase (tranny) gearing and the carb jetting to be different. Is anything else? Would the jug or head interchange? Intake and exaust porting the same? How about bore & stroke? The ATV is a good bit heavier...would the bottom - end be stouter? I`ve only seen Suzy`s and CR`s...is thier any Kaw`s or Yami`s? Thanks for the imput!

a cr 250 seems to be the way to go. dby, esr, skeetz, are a few good engine builders. im in favor of dby because their shop in in my area. As for the 250r i believe they are case inducted so you you probably wont find much that swaps over.

Where are you located? Is the 270 that much better than the 250? I believe the X1 car at Middleford was beating 270`s with a stock 250. I know the total combo is what really wins. I am concerned with the weakness that is created when the lower end is stroked. I hear that it doesn`t last long. But I recon i`ll still need to go bored and stroked to be a contender. I will be very interested in a reliable engine builder though! That was why I was wondering about the ATV motor - buildability and durability. Thanks for your advice!

im in knox pa dby is in ford city about an hour south of me. duribilty will always suffer when it comes to performance. whether its a 400 small block or a brigs and stratton. I personally do a top end rebuild every 6 races. costs around $140. which i feel is reasonable considering how we crank these motors.

Yes, That sounds like a good insurance policy to me as well. I used to do a top end on my 100cc yami`s back in the day, about every 3-4 weeks running Cam II. Alky is another story. `Bout how long does your bottom ends last? How often should I get the berrings and rod bolts replaced? I would love to have comparisons of all the hp`s and torque ratings of the various motors. Can-Am, Husky, Bombardier as well as the big 4. Thanks for your wisdom on this!

every winter for the bottem end. i only have 1 motor so im carefull. a season for me is 16 races. i believe it 25 races on the bottem end but mine wont ever see that many.