Hispeed Carb?

[kiske]

Has anyone had any experience with hispeed's carb line?

My drag racing friend says they are good, and comparable to PWK carbs, for which they seem to be replicas of.

Anyone know if they are any good? I was thinking of buying a PWK, but at less than half the cost, these are quite tempting. A 32mm Hispeed carb is about 2.5k whereas a new PWK is between 5-7k.

Thoughts?

I can't post a photo/link, so you will have to use your google-<deleted>!

[KRS1]

What kind of bike is it going in ?

[kiske]

NSR150 - I was toying with boring out the SP carb, but it's a pretty shitty carb to begin with. I just told my friend to order one in. So I will give my 2c in a few days, I guess.

[karlos]

Just my opinion, i would buy the genuine article if it were my choice.

Edited February 19, 2012 by karlos

[KRS1]

I bored an SP carb and put it on a CBR 150 before. The fake carbs are hard to tune, but the real ones are easy. The fake ones have loose slides and the bypass holes are roughly drilled. The real ones have the serial number laser etched, looks like a bunch of dots, the fake ones are stamped.

I bored mine to 32mm inlet and down to 29.5mm at the venturi, and smoothed out the intake end, no need to oval bore these, the idle screw can lift/drop the slide just fine. You can't get a full 32mm from them, the slide wont lock in place. Not much difference at all from the original size of 28mm and i tried about 15 main/slow/needle/air screw combos.

An adjustable needle works wonders for these carbs, but you can shim the needle with a small washer and its the same as going down one clip position.

What was it you didn't like about the NSR carb? Don't forget to compensate for the 2t autolube when ya stick that badass 32mm in and bend the reed limiters up a little.

[kiske]

did you use the stock inlet bored on the 32mm?

Interesting to know that there's no real difference between the 28/32 - I would presume there would be a signifant boost at high rpm?

I tested a 28mm PWK carb and it felt more responsive. Althought that might have been a placebo effect, hah.

[KRS1]

My carb wasn't a true 32mm, it was only 29.5mm....you go by the hole size at the slide. It tapered down from 32mm at the mouth to 29.5mm at the slide hole. I had a 34mm on an NSR in the past and it made a big big difference. If you have idle problems with the 32mm remove the resonator chamber on the intake tract and plug it to bring up the velocity.

The PWK's are more responsive at low-mid end, but i've found that from mid-top end they're about the same as round slide carbs. There's less restrictive surface area on a flat slide than a round slide, but once the air velocity builds the differences become negligible.

[kiske]

Thank you for all the info KRS1, I'll let you know how the hispeed carb runs.

Never knew I'd be getting tuning advice from a hip hop legend, eh.

[VocalNeal]

NSR150 - I was toying with boring out the SP carb, but it's a pretty shitty carb to begin with. I just told my friend to order one in. So I will give my 2c in a few days, I guess.

There used to be a "racing" carburettor kit from Honda for the 150. IF you can find one.