Hi, I would like to know if I would see a great difference by putting a 350X carb on my 300ex. The guy that sold me my quad had one and already putted it on it and said that it was really good but the only problem was that he was always hitting the rev limiter. Is it dangerous for the engine because I heard the valves ticks more when he puts it on? THANKS

 

Hey, haven'T anybody tried this?

 

A carb wont make your valves tick and I dont really see how one could be dangerous. Is it bigger than a stocker? if its alot bigger you may lose some power from not enough velocity (unless you mod the motor a bit). If its a touch bigger you may gain top end at the expense of bottom end, and If its too small you will gain torque and lose hp.

 

I know the 300ex carb is 32MM and the 350X 31mm. what would it do?. Big difference?

 

Anybody? This isn't really complicated to answer !

 

Unless you port the head and get a bigger cam and exhaust you will see no difference at all.

 

Downsizing 1 mm you probably wont notice a thing unless they are of different design. Example, if one were flatside and one were butterfly or one had a big choke in the way (400ex) and one didnt.

 

The guy who've seen the quad with that carb ( I didn't) said that It was quite impressive but the quad hitted the rev limiter too fast

 

I have a 350x. what wouldd happen if i put a 38 mm on

 

You'd be a lot better off with a 400EX carb. The 400Ex carb (@ 35.5mm) is larger than both the 300EX (32mm) and 350X (34mm). It also has an accelerator pump like the stock 300 carb -- the 350x carb does not have an accelerator pump.

The 400 carb is readily available and cheap. All 3 carbs are of similar design with the exception of the missing accel pump on the 350X carb. In fact, I've heard a friend claim that his 350X felt like it ran better with the smaller 300EX carb - my guess is because of the accel pump.

We've done the 400Ex carb swap on a 250x and it ran well. Although, the 250X had a cam, piston, and exhaust. Can't say how much it will help or hurt on a stock 300ex.