Anybody have a 38mm A/S on a small bore?

[wilkin250r]

I've had it with this stinking carb, I think I'm going to put my 38mm A/S on instead.

Anybody running a 38mm on a stock bore, or maybe 265? What jetting are you running? I need a ballpark area to start with, and then I'll fine tune from there.

Do you have any problems with throttle response?

[pismoracer]

thats alot of carb for stock bore?(unless you have ported it)

i would run a 36mm or a 34,

[zedicus00]

ive got a 39mm pwk on a stock bore cylender. i wanna say between 47 50 and like a 175 main needle in the midle. dont qute me though its been a while since i messed with the jetting

[nacs400ex]

Originally posted by wilkin250r
I've had it with this stinking carb, I think I'm going to put my 38mm A/S on instead.

Anybody running a 38mm on a stock bore, or maybe 265? What jetting are you running? I need a ballpark area to start with, and then I'll fine tune from there.

Do you have any problems with throttle response?

Im wondering the same thing. Ballpark range for my 265.

[wilkin250r]

Originally posted by pismoracer
thats alot of carb for stock bore?(unless you have ported it)

i would run a 36mm or a 34,

I agree, but I don't HAVE a 36mm carb. Actually, I do, but it's working like crap, no matter how much I rebuild it, or what I set my jetting at.

However, I DO have a 38mm, so I'm going to use that instead.

Motion-Pro sells a cable to use with the stock thumb and the Air Stryker carbs, right? Anybody know the part number?

[brokenbones]

on my ep 265 i run 50 pilot,deg needle on the 3rd clip and a 152 main and it rips i am sea level


my 2 cents

[250R-Dee]

Basically you will get LOTS more air into the engine so you will have to rejet the motor according. My Krank-it racing slug is a 310 but it is only 257cc at the moment. It has a Nationals MX port job that is supposed to produced lots of mid to top power.

With my 39mm AS (at sea level right on the water) so I am gonna start with:
clip at the center
50 pilot jet - (have 52 and 55 jets)
172 main jet - (I have 168 through 200 jets)

I will be running a 40:1 mixture HP2/95 octane fuel without an air box lid.

[pharit]

runs good on my 86 i run an open air box too and mines only 80 over

[8dave3]

I have the A/S on mine.Its .50 over with Rad valve and Sparks pipe.Main is 165 now when its warm I can go to a 160.The A/S design allows for a bigger carb without giving up bottom end.

[baker250r]

I got my stock carb bored out to a 37mm. They just took it in to a lathe and ran a bit thru it. it rips for me.

[Flynbryan19]

On your smaller carb is the walls of the carb where the slide moves grooved/worn out? This will make you pull your hair out with jetting.

[wilkin250r]

Originally posted by Flynbryan19
On your smaller carb is the walls of the carb where the slide moves grooved/worn out? This will make you pull your hair out with jetting.

Actually, I think the choke/idle is bad. On the 4-strokes, the choke is a butterfly valve, and the idle is a throttle-stop screw. On the 2-strokes Keihin, the idle and choke is a separate air passage that bypasses the slide.

As such, when the slide is wide open, the choke has no effect at all, because all air just goes through the slide. But at idle, with closed throttle, all the air goes through the choke passage.

And this is the problem I'm having. My jetting is spot-on at WOT and high RPMs. However, at idle, my quad WON'T idle, and constantly fouls plugs, no matter what my pilot jet is, or what my air screw is set at.

I think the choke is stuck wide open, and I can't seem to fix it. With the choke on, it doesn't matter WHAT I set my jetting at, it will constantly foul plugs.

[hrc85250r]

dude, just call sudco or ESR or somewhere that sells these and get specs for it...they will help you set it up for elevation and everything....just tell them what you have for a motor and whatnot and they will tell you what you need....