biggest piston in stock 86 cylinder?

[Elduner]

Whats the biggest slug I can stick in the stock cylinder?

My wifes bike needs a rebuild and I want to make sure she has some power for when she races all the other gals in the group.

I have a spare 86 jug that I have ported but just want to make sure I go as big as I can on the stock jug with out having to resleeve... I will resleeve when needed... But even then I have another stock spare.

le me know

[zedicus00]

.140 over though finding that piston may be hard, i hear jetski pistons work but havent found out what they are from yet. .120 over is a lil more comon, have the jug cryoed, its fairly comon for these big over bores to crack the sleeve. keep the engine as cool running as possible.

[Elduner]

.120 what does that bring the CC's too?

I was going to have the jug cryoed. But want to buy the piston so they can do everything including the over bore and hone.

My wifes 250r is so reliable that I dont want to take any chances.

[lbz#7]

69.5 273cc

[deathman53]

I would bore it 1 over what it is now and port/polish it. a good port/polish job will do alot more than a big bore will ever do. On my 250r I had a 120 over piston and it started to crack the sleeve and there was 2 cracks in the jug that could be seen. Do you want to resleeve for every rebuild????? Thats what will happen if you get a 120 or 140 over piston.

[Tom TRX250R]

I agree with deathman53, boring out your cylinder to max bore on stock cylinder will not bring near the power a good port/polish will bring. Basically you are simply wasting future bores. I would go a .10th over and do a good MX port/polish (C-Leigh Racing is a good guy to get an excellent port job from) Unless you are going big bore, I would focus primarily on port/polish, carb, intake, and good pipe/silencer combo. This will provide much better results then simply wasting several future bores and boring it out. This not only will run better but will be much more reliable.

[86 Quad R]

i 3rd that of which tom and deathman said....................... there is no need to waste future bores on stock cylinders. a good porting (mx/play) along with well matched exhaust and intake components will/can make a lil screamer. lotta power to be had outta a stock cylinder.

[Elduner]

The spare cylinder that I have needs to be bored out anyways.... Im a duner and my bikes only see sand...

I do wanna get a port and polish job on that cylinder. But since I need a new piston might as well drop in a 69.00mm in there.

I currently have
38 mm Air Stryker carb
VForce reeds.
ESR (Mid/top Pipe)
No airbox with a K&N

So who can do a nice port & Polish job for mid to top end.... I just Dune ... No woods or MX riding for me...

The Wifes 250r
http://i2.photobucket.com/albums/y2/elduner/dumont055.jpg


My 450r
http://i2.photobucket.com/albums/y2/elduner/450r/IMG_0079.jpg

http://i2.photobucket.com/albums/y2/elduner/450r/IMG_0059.jpg


My 450r running a built lt500r
http://i2.photobucket.com/albums/y2/elduner/450r/dumont20pics20lots20of20pics20012.jpg

[fireburns99]

are those pics from glamis?? The area doesn't look familiar.

[zedicus00]

have c-leigh racing do it, tell him you dune it and need it to rip hard, he will do it up right.

[Elduner]

Thats Dumont not Glamis.

Dumont is off the 15, 30 miles west of Baker.


Does anyone know how to get a hold of c-leigh? I emailed him and have not heard from him.

Also what is a ball park figure on what he charges?

[zedicus00]

ive got his number laying around somewhere. ill pm you when i find it. hes been awfully hard to get a hold of latly.... considering the whether im sure hes been busy as hell though... riding season and all you know...

[spent21]

K & T performance in Utah are excellent people to deal with. i sent a brand-new, virgin bore 250 cylinder to him, and i have WAXED ct 310 kits left and right. i haven't even had the bike out since the 450r came out, so i don't know how it fares against them.

i had kim give me a mx port/polish, deck the head, and match my intake. it was about 5 years ago, but i want to say it was around $325 for his work.

he asked me several questions (my intended use for the bike, pipes, fuel, etc.) and gave me a lot of advise. he decked the head enough that i can run the atc head gasket and stay on pump gas. change to the thinner cr or the trx gasket and bump up the compression enough for race fuel. i've never actually run the thinner gaskets since i have never needed the extra power.

esr pipe (trx-6 i believe), 38 airstryker, atc head gasket, and a UNI filter absolutely rips.

they do mainly sand drag bikes, but i have never had a complaint with my bike. i research any major purchace, and i heard nothing but great things about these guys. when i first called him he spent an hour on the phone with me before i ever told him i was sending my jug to him. i can't say enough about them. top notch.