350X carb

[350xryder]

Are two stroke and four stroke carbs interchanable, I want to put a 38mm on my 350X and want some ideas on where to start.

[ATCRYDER]

Yes, you can use 2's on 4's and vise versa.....but technically theyre differant. You wont notice a differance...although its pretty poinltess using an R carb (which i assume you wanna use) when aftermarket 400EX carbs are readily available.

[350xryder]

I am going to start looking for a carb and just wanted to know what my options were. Would a aftermarket 400ex carb be best, or could I buy a used carb and still gain power.

[Da_Catt]

now most 4strokes come with a carb that has a accelerator pump. That is one difference between 4 and 2 stroke carbs. a stock 400ex carb is a good up grade, but not a big as you want. it is only 35.5mm which is a little bigger than stock but it has a accelerator pump.

[bbechtel16]

What does the accelerator pump do and how does it work?

[JohnR.]

Generally on a four stroke you'll want to use a Keihin PE type carb, the '85 250r came with a 34mm PE. After doing the mods I had to upgrade the carb because it was a bear to start with the little carb. I had the stock carb from my '85 R and I was going to rejet and run that (it think that would have worked OK) carb but when I called Duncan Racing they talked me into getting a new 38mm PE with a twist throttle and a jet kit. I have to say I don't regret it a bit, the machine starts better than most stock 350X's, will run with a stock 250r in a drag race, and will idle all day long without a hiccup. It took some time to get the jetting down 100% but now it is really a joy to use that trike. You can spend a small fortune on some crazy trailprotrailprotrailprotrailprotrailpro Edelbrock carb but for my money get a PE and you'll be happy you did. As for an accelerator pump, when you hit the gas it shoots a small load of fuel in the carb throat (similar to a water pistol squirt) to be sure there is no lean spot. The PE has no suck pump but mine is right there when I hit the gas.

John