313,330,350 kits?

[300exrider1]

Can someone or some people please tell me some about 300ex big bore kits? What kind of gains will I get is it worth the money? What does it cost. Where can I get this? Thanks... Also I am new here and I am not 100% sure if this is where this post goes?:huh :confused2

[300exrider1]

?

[300ex-boy]

The bore kits work great if they are done professionally. Send it in to ProFab, or GT Thunder. They do good work. The power gains are great. Spend the extra money and get it done. You wont be dissapointed! It'll cost you anywhere from 1000 to 2000$.

[02_300ex]

$1000-$2000? the kit is $315

[ThyJuGGaLo]

Originally posted by 02_300ex
$1000-$2000? the kit is $315

hes talking about spending the extra money to make it run as good and reliable as possible, and with that it comes out to $1000-$2000

[ride300exrider]

$1000-$2000? the kit is $315
meaning if the place u get a kit from profab, gt thunder....... any motor place, puts it all in and does all the shop work also replacing any motor parts that are needed.

[bradley300]

that also includes port work, and you can get a gthunder 350 for less than 1500.00;)

[Gatorman199]

Why not just sell the 300 and take the $2000 and get a 400ex?

[bradley300]

my reason was A, i dont like 400ex's, B 400ex's are not allowed in my gncc class and C, a 300ex is what was givien, so i'll just work w/ what i got

[bradley300]

D, my 300 will smoke a 400ex:devil: :D

[Gatorman199]

good point about the gncc but other than that id persoanlly just rather have a whole new quad run faster than your will and still have it run the way it was engineered to.

[big bad beny]

Bradly300 what all is done to your motor me and the boss are thinking in puting in a 345 or 350 in my 300EX and what is the differnts in the 2 and how much would it be with out labor.What kind of head and cyleder work do you have done?
Did you do eny thing to the trany to make it hold up and dose the crack did eny work?








P.S. Ride Red and Ride hard

[bradley300]

my motor was built totally by gthunder, it has a true 350cc big bore, 11:1 compression, HD rod, clutch and valve springs, full race port and valve job with a white brothers mid-top cam.

my motor is just as fast as the FST 345ex in the sport class gncc's and he has what i would consider too high compression (he runs 13:1) he has more low end, but i stat right w/ him mid to top.


i didnt do anything to my tranny nor had i heard anything about it until mickey dunlap mentioned the "3rd gear mod" but, he semed to think that since i didnt send my motor to him, that i must not have enuff power to worry about it :rolleyes:

the differnces between my motor and FST"Ss riders are this

he has more compresiion, the cam is probably different and mickey has different porting specs than lazarus. i think FST is still running the stock carb also and i have a 400ex carb

[JIMFROMTEXCO]

ive got a 330 and if you like running stock 400s i recomend it! im running a 11:1 compression and its fine im getting an oil cooler and my kit is a tc racing
the stock piston will fit inside the 330 piston i have lol

[big bad beny]

ya my motor builder from WHITE HORSE RACING has never done a 350 so thats y i was asking. DiD you put a sleve in your jug?


P.S. Ride Red and Ride Hard

[300exrider1]

Can you give my some web sites and what all I could take? Right now I have dg pipe K&N and that is about it... i want to take a kfx I dont want to loose relialibility and I want it to be worth the money! ;) I will spend as much as I need to get the best though! No limit but i dont want to spend a fortune or get a waste!
Thanks

[02_300ex]

does anyone reccomen getting it from curtis sparks?

[bradley300]

beny, gthunder did all the labor on mine.

from what i have heard, curtis sparks builds great 300ex motors, but good luck getting it back this year:(

[mersingt]

www.powroll.com
i was lookin at there 350 stroker motor kit but then i went broke
people say that 330s will beat stock 400exs

[oste]

Why not get a 380cc big bore stroker kit with hi-comp piston. I've seen this size beat 400ex's at oval ice races.

[300exrider1]

Iv seen that powrol one but I havent ever seen these gt thunder's and I could take a 400ex with a 330 kit?

[bradley300]

with a 330 you should be able to take a stock 400ex, a 350 kit is dead even w/ a stock z400

[300exPat]

do they even have 380's?? Where?? How much?

[oste]

The one I saw was a TC motor, running race gas. I prefer my local engine builder though, cause if I got a problem I'm not long distance SOL.

If you are serious about racing (and winning) I'd recommend the race gas mod (not just hi-comp piston, head mod too). Any High performance shop should be able to get you one of these. It depends on how much you want to spend. For a 380 kit you're looking at $1500.00 or more, but it will include porting and all that type of hands on workmanship expertise.

QUOTE]Originally posted by bradley300
with a 330 you should be able to take a stock 400ex, a 350 kit is dead even w/ a stock z400 [/QUOTE]

[02_300ex]

i herd from somewhere that the 11:1 ratio u cant use the electric start is this true and if it is how do u start

[Dunlap]

I have run my 380's on pump gas with the stock starter at 12:1.

[02_300ex]

thanx

[250rider]

i cant beleive i am hearing of a 380. technology these days is crazy!!!

[TRX300X]

If you're going to do a big bore on the EX or X engine, it's best that you split the cases and do the 3rd gear mod. After I got done with my X engine I lost 3rd gear in a matter of minutes. It's no fun to have to pull your engine all apart after you've just spent so much time building it up. I've got the 80mm piston kit in my X with a bunch of other stuff and it just plain screams. It's very torquey and has lots of mid range. The power is very predictable and it's smooth.

I've got 80mm big bore kit 11:1 compression, Stiffer valve springs w/ titanium retainers, .336 lift and duration billet cam, head milled .006, ported head, oversize valves, choke baffle removed out of carb, 350X intake boot, UNI air filter, Powroll 3" supertrapp with oversize header, no air box lid, KG clutch with springs, 300EX oil pump and the 3rd gear mod (The last two I did because Mickey Dunlap helped me solve my oil pump and third gear failure problems)

Also if you do the 3rd gear mod on a 250X I HIGHLY RECCOMEND that you get the new gears I think it's the 3rd and 4th gears on the countershaft if I remember right. The 250X ones only have 3 dogs on them and with a built engine you'll round them right off. Buy the 300EX ones they slip right on and the extra dog on the gear makes all the world of difference.

[ghak99]

Originally posted by 300exPat
do they even have 380's?? Where?? How much?

380...lol, It takes a 410 " actually a 406 or 407cc motor" 250x or 300ex to run and win at our local flat track. They have finally made a few move up the next class, but the slower riders with the 410's are still running the class.

70mm stroker crank and 86mm piston is what you need!;)

[Dunlap]

The 380/390's I build out run the 428's I use to build. The reason is because of the longer rod to stroke ratio lets the motor breath better and the lighter piston revs quicker. And the best thing is that it's cheeper than a stroker kit on the 300ex's anyway.

[ghak99]

Originally posted by Mickey Dunlap
The 380/390's I build out run the 428's I use to build. The reason is because of the longer rod to stroke ratio lets the motor breath better and the lighter piston revs quicker. And the best thing is that it's cheeper than a stroker kit on the 300ex's anyway.

I understand and probably agree with your reasoning, I don't know where they get their 410's built at, but they fly!

[JDiablo]

anyone ever hear anything about the hetrick 310 kits?

[honda250xrider]

mickey what kind of power are you getting from your 380-390 kits? what kind of torque numbers if you have any dyno runs?

[Cody_300ex]

Originally posted by 300exrida
anyone ever hear anything about the hetrick 310 kits?

POS, Gt thunder!:macho

[JDiablo]

^^^ YOU STFU~!!!!!:p