what is the biggest you can bore the 300ex? [Archive]

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bigbadbrad

10-15-2002, 04:54 PM

what is the biggest you can safely bore the 300ex without having to resleve it? will it keep it's relibility? how much does it cost ? what mods do you recomened with this mod? who sells the pistons i can get for this. which one is better true 300, 305 or 310? i ride the trails mostly and i plan on racing a couple of motocrosses a year.

thanks

bigbadbrad

10-15-2002, 04:55 PM

bumpity bump bump bump

10-15-2002, 05:26 PM

i think you can get a .40 over bore for it so that is around 40 more cc so it is like a 322cc or as fst calls it a 330ex.

Chef

10-15-2002, 05:30 PM

Originally posted by raptakilla14
i think you can get a .40 over bore for it so that is around 40 more cc so it is like a 322cc or as fst calls it a 330ex.

a .040 bore is NOT 40 more cc's. A .080 on a 400ex is only 19 more cc's. You must resleeve to get a 330. I think you can probably make a 300 or 305 on just boring....

DEAL

10-15-2002, 05:32 PM

I believe you can go to a 314cc maximum on a stock 300ex sleeve.

bigbadbrad

10-15-2002, 05:40 PM

bump
then i will prob get 305 in case i blow it
does any one have a 310 or 305 kit and how much of a difference will it make

96300ex

10-15-2002, 06:00 PM

.80 over, it's like 302 or 305 or something. you'd be better off getting a 330 kit. actually for the money, head work would give you the best results. porting and larger valves is where the power is at on a stock motor. you bore over without it but your results will be pretty lame at best

Buzzsaw

10-15-2002, 07:14 PM

I've got a 316 is i think it's .80 with 11:1 and flow work

96300ex

10-15-2002, 07:33 PM

How's it run? My bros needs a rebuild, so you know we just gotta hot rod it while it's appart;) , how much you pay for the flow work and where? like i said that's where the power's at... sit down with desktop dyno for a little bit and it's not hard to tell that head came off a 250:rolleyes:

Buzzsaw

10-15-2002, 08:07 PM

like a raped ape, like 300 for the flow work

Live2Ride300

10-15-2002, 08:11 PM

hey buzz, u got ne anoteher pics of ur 300? About how much did ur whole motor job run ya, if u dont mind me asking? What are u running out back for suspension, sorry this isnt in the suspension forum, i just figured id catch ya here.

96300ex

10-15-2002, 08:16 PM

hmmm, guess i better not try porting it myself... dang too much $$$

Buzzsaw

10-15-2002, 08:25 PM

Well it was 1150.00 that's Yosh full system, flow work, cam, piston
harder rockers, valve job, valve srping, new k&n filter outer wear, labor and alot more bad momery. I'm get LSR +2 swingarm, carrier, anti-fade, shock.

96300ex

10-15-2002, 08:36 PM

Sweet, i think i just picked up a set of 400ex a-arms and shocks. might have to fab some brakets if she don't sit level. Know of anyone who has tried home porting a quad head? I can do a car but that dude looks a lot different...

Buzzsaw

10-15-2002, 08:51 PM

Need to get new pic tomorrow when i put the new black beadlock w/red ring on.