330 big bore questions.

[Atlanta]

Ok,let me start off by saying I love the 300 I have built,but until I tear it back apart,coat the frame and change my wheels/tires and plastic out I think it looks old and worn.

got to love it when I have about 3K invested,lol.


I do want more power though and thought a 330 big bore kit,400ex oil cooler and a hot cams stage 2 would do the trick.

I do have a couple questions.


How reliable are the 330 kits on eBay,with je or weisco pitons?

Will the 300ex carb be enough air flow or will I need to run the 400 carb?

Who makes a solid clutch for the 300 that would hold the extra power I will be putting down?

Last and the most important to me.

Will the bottom end be able to handle this setup with normal maintenance?

I am not someone who is going to bang out the rpm's @ redline all day but want the added torque.

I was also thinking of a lighter flywheel but again I am not wanting to piss on the engine life just for a 1/4 hp.

Would simply a cam,carb and sprocket do this or will the 330 kit be night and day over the stock bore?


I can build this motor myself,it's not a question of how to,but rather will this be a waste,asking someone who knows or may have traveled my path and has some incite on a maybe a better idea.

Thanks in advance.

[smr]

personnelly I am not a big fan of the 330 kits. If you really want more power and keep reliabilty then bore it out .80 over and install the stage two cam hot cam.

Yes, install the 400ex carb.

run a uni air filter...stay away from K&N, they are no good for the dust we have in the southeast.

Get you a good pipe...Everybody that knows me from the races knows I am not a big fan of aftermarket pipes but the 300ex is an exeption to the rule. Don't just git a loud pipe, get a good one.

Unless you are gonna race I wouldn't worry about he clutch until yours wears out.

This is all I had done to Holdens last 300ex and he could actually pull a 400ex in the short distance and the motor finish many xc races without giving out. He won a couple OMA races and finished in the top 5 several times at the GNCC's with this motor. It was still running strong when we sold it last year.

[Atlanta]

Is the White Brother e Series a good pipe?
I have it on my quad now.

The 400 carb,is not a problem.


.80 over is a bit much on the stock cylinder,would a sleeve be the better investment for this bore?


Thanks for the input.
I am going to order the cam,carb today.

So I am up in the air,330 big bore or 80 over I guess.

I want to know what compression piston you ran @ .80 over?

What kind of reliability would or should I have with this for goof off riding.
I ride local tracks but not a racer,I also ride cleared land and some sand.

Hope this helps,and thanks again.

[smr]

.80 is the most you can go on a stock sleave. We never had any problem. Don't remember what the compression was but is wasn't a high compression piston.

White Bros e series is a good pipe.

[honda300EXtreme]

the 300 has more power to be gained with head work and an agressive cam.

to the best of my knowledge hot cams does not make a stage two cam shaft for the 300ex only stage one.
look into web cams or curtis sparks or Four stroke tech.
these cams will however require hardweld rockers and heavy duty valve springs.

now the real gains will come from the head a mild port and polish and over sized valves will do wonders for that motor.

you will want to use a 400ex carb it makes a heck of a difference.

i would go .60 over just to clean things up with a 11:1 piston and you would have a good running engine

[honda250xrider]

I personally would not go .80 over. I would stick to .40 or .60; .60 being the biggest i would go on the stock sleeve.

There is tons of head work that you could be doing instead of the big bore. Get yourself a port job, valves, cam, hi compression piston first.

I would get all of the head work done and over with, that way if you ever do decide to get a big bore you will actually be able to reap all of the benefits of having it.

The big bore will yield results but not nearly as much as it would with having the proper head work.

When I still had the 250, i went with a +3 intake, +1.5 exhaust valves,custom fst cam, full race port. I had this for several years with a 298cc stroker motor. It would pull like a raped ape. I used the same exact head for the 406cc stroker/big bore that I built a few years later.