just a few questions.

[xela456]

#1 has anyone ever done an oversized piston in an 86 br
#2 where would i find one
#3 did you notice any difference?

The reason i ask is i recently got a parts machine for my 86 250es and it came with an extra motor. the PO removed the output shaft from the tranny dropping the gears into the case so i figured since i basically have 2 extra motors for my rider and this one has to be split to fix anyway. Why not make this thing one bad motor scooter.
any thoughts?

[Flyingw]

The BR and SX motors really weren't designed to be high performance machines. They do make over-size pistons but those are to accommodate cylinder wall wear. The CDI has rev limiters and very tame ignition curves so even if you did hop the motor up, the CDI would null out those improvements. The BR is best served left in its original configuration for durability and longevity.

[kebby28]

Thats good to know. I have been thinking someone did something to mine. I have incredible low end power compared to a couple of my friends 250es's. But we all top out at the same speed.

[xela456]

thats good to know flyingw. and a race machine is not what i seek. i'd like to have the same kind of low end power you speak of kebby. mostly because i plan on putting the same executioners you have on my bike. i could care less about speed i just want the power!

[Flyingw]

The BR bottom end torque comes from three features, lower gearing in the tranny, larger ring gear in the diff, and the 25" tires that came stock. The SX has a higher geared tranny, one tooth less on the ring gear, and 22" tires. Perhaps going to a 350X carb and 22" tires would give you what you need. My SX has a BR motor in it and I can surely tell the difference in the bottom end.

[oscarmayer]

the do make performance cams and stuff for the 250's./ i have a rear 2mm hi comp piston that I am saving for when i get me a sx one day. they did do performance pistons back in the day too. but as stated these were never used for racing. just better umph.