300EX-- how does this combo sound?

[quadfamily]

I'm preparing to build my 300EX motor and I thought I would run this setup by you guys. I will be using a 330 kit with 11:1 compression and ported head. Maybe larger valves. I've also got a White Borthers all around cam and Kibblewhite valve springs with Titanium retainers. It will be breathing through a 400EX carb with choke removed and a 350X air intake tube. Keep in mind I've already got the cam, carb, valve springs, and air intake tube. I've also got an oil cooler on it. I'm not going to be entering any competetions with my quad, it's just for fun. Basically I am curious what some of you guys who have built 300's have to say about this setup. Is the cam going to be big enough? Do larger valves make a big difference or not noticeable? I want to run pump gas so please refrain form telling me to run 12.5:1 compression. Thanks alot!

[xx3003xrdrxx]

youll be beating 400 ex's :devil: thats all i gotta say

[hardkoratvmxr]

you should get a sparks cam instead of whitebrothers, my opinion though

and maybe a pipe and high rev box to use all your power effeciently

[kbass24emtp]

You will need to get a pipe and a high rev box. Sparks has both. If you don't get the box you will be hitting the rev limiter alot, and a pipe is a must with the mods you want. I had Ritter Cycles build mine. I do not know what cam he used, but it had great power.

[bwamos]

I'd reccomend on the Valves to get:
Oversized Exhaust and leave the intake stock.

Stock size intake valves will keep your velocity high for more torque. WHile the Larger exhaust valves will allow gasses to exit faster robbing less horsepower. (best of both worlds)

Get a Sparks Cam (I have the MX grind I liked the feel of it better than the all around the 300 has a flat enough curve anyway, wanted a little spike), Sparks X-4 exhaust, and have him mod your CDI Box for higher revs. (still gives you gernade saftey, stock is terribly low rpm)

As a side note, you will want to add an oil cooler (just grab a tranny cooler from the autoparts store same thing and you'll pay $50 less for it, lol).

As for Jetting (pretty much your setup) I'm running 142 Main, Stock Needle clip in 3rd from bottom, and Air Screw 3.25 turns out.
I'm running at a 13.5:1 ratio across the whole range. I like it a lil rich at idle. Helps keeps it from having that little lul at the bottom when you gun it before the acelerator pump fuel makes it to the cylinder.

[hondardr4life]

I can't believe you're running a 142 with a 330. I have a 148 in mine. I like my motor set up a lot, all my mods are in my sig if you want to read them. You will eventually get bored of it though. It didn't take me long, I am in the market for a 250R.

[bwamos]

Originally posted by hondardr4life
I can't believe you're running a 142 with a 330.

Runs a dark golden brown on the plug. Proof that every machine is different even with the same mods.. lol.

I run between a 140 and a 145 depending on where I'm riding. Leaner in the dunes and richer in the heavy woods. More trees = more oxygen density. ;)

[hondardr4life]

Sounds like you really know your stuff. That does show that everything runs different.

[Out_Sider]

i like web cams myself

[dork]

bigger engine with a smaller carb will sometimes pull more fuel out of the jet because of the stronger intake pulse. small carbs flow more fuel, big carbs flow more air.

i think you may want to get oversize intakes though. it improves the volumetric efficiency with the larger bore. especially since the 300 has small valves to begin with. they will improve the power across the board, especially in the mid and top.

definitely regear when you're done, 14/36 works good.