Max 300ex Engine Mods

[rooster300ex]

I was wondering how much horsepower could u get out of a high i mean highly modified 300ex engine, how much can u beef them up. what do u have to do. i know curtis sparks has a 396 stroker kit, i'm just wondering if thats as big as u can go.

[ride_red666]

not as much as a stock 400ex. it would be alot cheaper to sell ur quad and buy a 400ex since you can get a used one for really cheap right now and then mod it it.

[Cody_300ex]

Originally posted by ride_red666
not as much as a stock 400ex. it would be alot cheaper to sell ur quad and buy a 400ex since you can get a used one for really cheap right now and then mod it it.

You can make almost double what a stock 400ex makes, but the money used to do it could probably buy you one. But you can get a 300ex up to around 40 HP but its gunna require a top name engine builder like TC, GT thunder, sparks, ect. Just ask bradly about his 350.

[rooster300ex]

Originally posted by ride_red666
not as much as a stock 400ex. it would be alot cheaper to sell ur quad and buy a 400ex since you can get a used one for really cheap right now and then mod it it.


if u bought a 400ex i would have to start over with frame mods and **** like that. if i had the money i would have one bad *** 300ex. do u think by the time i got it around 40hp i could outrun a 85atc250r.

[Cody_300ex]

It would be a close race, and to tell you the truth i really do not think its worth your time and money, you may put 3 grand in that motor and have a hard time getting 1 grand ot of it even with dyno sheets to prove it. If that dosnt bother you then I say go for it.

[BLACKeR]

do u think by the time i got it around 40hp i could outrun a 85atc250r.

no, the ATC is going to weigh 100lbs less than your EX. if he has any mods at all, pipe filter etc it wont be close.

[TRXRacer1]

Originally posted by BLACKeR
no, the ATC is going to weigh 100lbs less than your EX. if he has any mods at all, pipe filter etc it wont be close. It's 75lbs and if you managed to get 40hp out of the rear of a 300ex (good luck) then yes you could run with a STOCK atc250r.

[bwamos]

Bone stock.. yea... probably. But, it will still rev a lot faster since the 300ex is now a big bore stroker. I'd bet the atc250r would still pull away in a drag race.

My 330ex runs in the 34hp range (give or take a couple depending on the dyno), I will beat a stock 400ex, run side by side with a pipe/filtered one. But, add a cam.. and I'm back to square 1.. lol. I've got around $1800 into the motor (including the sparks pipe, K&N filter, and Carb). It still gets smoked by your average 250r (pipe/filter/reeds/carb/etc) in the dunes. They aren't a high performance machine, but they are fun.