which carb should i get?

[kyleschonert]

a stock 400 carb, or a Duncan 38mm Keihin PE carb? this is for my 300 with the mods in my sig.

[grumpy]

38mm?That is a huge carb!!!
I have a 32mm on mine,port/polish,oversize intake and exhaust,exhaust valves moved 10 degrees.
A smaller carb will usually give you better bottom end
A larger carb for the top end.
I wouldn't go any bigger than 34mm
Also take into a account the room you have under your fuel tank.Call Carb Parts if you want a new one they did mine for me,everything you need adapter,jets,cable,etc.I think mine was 279.00 for a 32mm mikuni flatslide
JUST MY 2 CENTS

[Cody_300ex]

Ive heard 34 and 38mm lectron carbs where hard to beat on a modded 300ex.

[kyleschonert]

so are you guys saying i should get this carb? but its not a lectron, those are a little pricey for us. and this one is only 150. lmk asap please. thanks for the replies guys.

[WildWestRacing]

Stay away from the kehien pe 38mm. This carb has an extremely stiff spring and is designed for a twist throttle. It also has a very long throw to it. We bought one from Duncan and the spring was way too stiff. You will have to modify your thumb throttle housing for the slide to open up all the way.

If you can overcome these problems you'll love the performance of the pe 38. It has a great mid to top end punch to it. We could not deal with the overly stiff spring. I'm taling, this is the stiffest spring on any carb I have ever felt bar none. This is do the carb being designed for a twist throttle.

We switch to a 400ex carb and it works great with our built 300ex. It doesnt have the mid to top punch that the 38 does but it is more responsive on the bottom.

From what I heard the Lectrons work great on the 300's. We are going to try one her in the near future.

Bill

[kyleschonert]

im so confused on what to do. lol. How hard would it be to modify the throttle? Could i just switch to a 400EX throttle or something? Id really like this carb, b/c i dont want to buy a new one, and dont really know if i want a 400 one. Im so confused though.

[WildWestRacing]

A 400ex and a 300ex use the same thumb throttle. All you have to do is grind dowm the little aluminum stop inside the throttle housing. Just be careful and dont remove too much material because you will grind all the way through the housing.

The 400ex carb will be a big improvement over the stock 300 carb with no modifications. It's a tight fit for the air box boot. The 400 carb has a light spring just like the 300 carb.

The PE carb wouldnt be so bad if you could find a weaker spring for it. I couldnt find one anywhere. I tried cutting the spring but it didnt make much difference. It still felt as if the spring should be used as a brake pedal return spring.:eek: No joke!


Bill