What size carb for 310 big bore?

[speedfreek]

I have an ESR 310 cylinder with mid to top end porting and i'm looking for more power. I currently have a 38mm mikuni flat slide on it but was wondering if it would be worth the money to get a 39mm or even a 40mm carb.

What are yall running? What do yall suggest?

The bike is used mainly for drag racing.

[methyman]

You can get your tm38 bored to 41mm and save some money. I prefer the Keihin PWK39. The pwk40.5 is not worth the price difference unless you running methanol.

[speedfreek]

Originally posted by methyman
You can get your tm38 bored to 41mm and save some money. I prefer the Keihin PWK39. The pwk40.5 is not worth the price difference unless you running methanol. Wow, a 41mm? I never thought about going this big. Are you familiar with running one this big on a 310?

I'm running VP110 octane race gas.

[methyman]

I run a 40.5 mm Keihin on my stock stroke stock cylinder that is ported. We run 39mm Keihin on stock TRX250R motor with a pipe and no porting and that thing rips!!!

[speedfreek]

I just remembered I have a 38mm spare carb!!

Where can I get it bored at?

[methyman]

Sent you a pm

[speedfreek]

Thanks Matthew. I will give them a call.

Try BDT Motorsports 909-802-6516 or Duncan Racing 866-379-7223...BDT Tapered Bored my 38 Keihin to 40.5MM race carb as well as pre-jetted for my old 310 ProX and it ran much beter. I also had one by Duncan in early 90's...

[albertp86]

I have an esr 310. I had a 38 and switched to an esr 40.5 and it is the best thing I could have done. I promise that you would never regret that bigger carb. If you do regret it, I will buy that 40.5 from you because I need another carb for my buddy's 330

[talon67]

I have an FTZ built 40.5 flat slide that was setup for a ported 310 stroker flat tracker. I took the engine back to stock and will make you a deal on the 40.5 if interested. Send me a PM if you'd like. HTH dave