Having trouble setting up 350x carb on my 250sx

[86trizinger]

Ok here is what I have:

1985 250sx
-1mm over bore
-Bassani Exhaust
-UNI filter
-no aire box lid
-1985 350x carb - just rebuilt with new kit

I am having trouble dialing in the carb. It wants to stumble and die right off of idle. Full throttle seems to be some what decent overall.. I can raise the idle and a just the carb a little and I can get it to drive finally.

I can't adjust the carb needle right now though since one of the screws that hold it down was stripped out. The plug looks like it may be a little lean on both idle and full throttle chops. Any help or info would be great. I would like to get this thing going soon.

[86trizinger]

Anyone have suggestions.

[86trizinger]

Any one with any input at all ?

[Dirtcrasher]

I used the SX pilot and the 350X main, turned the air screw out a bit and it ran great.
UNI
Lid Off
Cobra

Oops, forget - Midrange WEBCAM and 2MM over piston.

It's in the basement, I never ride it so I forgot........

[CI250SX]

With the idle screw being stripped it's gonna run lean reguardless, nothing there to seal the threads. What was wrong with your original carb? And why did you change it out?

[MrPretty]

With the idle screw being stripped it's gonna run lean reguardless, nothing there to seal the threads. What was wrong with your original carb? And why did you change it out?


A 350x carb is a popular mod for the 250sx. He probably just wanted a bit more power

[Dirtcrasher]

With the idle screw being stripped it's gonna run lean reguardless, nothing there to seal the threads. What was wrong with your original carb? And why did you change it out?

Idle screw? Does he ever mention "idle screw"??

An idle screw affects lean or rich conditions? :crazy:

He never says the "air screw" is stripped.

I think he means 1 of the 4 bolts holding the bowl on are stripped and he can't change jets.

[86trizinger]

totally screwed up what I was writing. The screw that holds the needle in place is stripped. I can't remove the needle to adjust the clip position. I think it is on the middle position.

The original carb has a cracked housing so I couldn't use that. The jets I got were the same exact numbers as the stock 250sx carb had. Not sure if I should just order a new carb kit and try again or what.

[Dirtcrasher]

You don't want stock 250SX jets, you have mods and your letting more air in now.

Remember, the needle affects from 1/4 to almost WOT so the right jets still have to be close. If a jet is a 138, thats all the fuel thats gonna go thru it.

Borrow/get a really good phillips (Snap-On/MAC), hold that slide solid and get that screw out. The more you mess with it with crappy ends on your phillips, the worse it gets. And don't reuse it!!

[86trizinger]

I have MAC screw drivers already.. Was a VW and Mercedes Tech for 10 years. It is already completely round. I called the machine shop I use and they said its under $10 to get it out if I can't.

I am not sure why but the 350x carb kit I ordered had the same size jets as the same as my 250sx kit. I am not sure if they sent me the wrong kit or not now. I will order another 350x carb kit and see if that helps..

[Dirtcrasher]

You can always use a regular drill bit and then deal with it, there usually not super tight and only about 3MM.

But better would be a LH drill bit and it may back right out.

Sorry if my "screwdriver" statement came out the wrong way, glad to hear you have good tools :beer Lots of guys don't know how important that is!!

[CI250SX]

Idle screw? Does he ever mention "idle screw"??

An idle screw affects lean or rich conditions? :crazy:

He never says the "air screw" is stripped.

I think he means 1 of the 4 bolts holding the bowl on are stripped and he can't change jets.

You're right he didn't. He just said that a SCREW was stripped but didn't say which one. I simply stated that if that one was stripped it would cause a lean condition not a rich condition, which I never did mention :crazy:. He also never mentioned anything about the 4 bowl screws being stripped either. Guess it's tough being the new guy here HUH?

[Dirtcrasher]

No, it's not tough being the new guy here. But when you give advice a week after you join, people might believe what you post.

I've never seen a stripped idle screw. Broken or seized air screw, yes......
If it was stripped yet still in the carb, I have a hard time being convinced it would run lean anyhow.
His original post said he couldn't get it out because it was "rounded", not stripped.

It's just in the wording of things; Everyone corrects one another here to try and help the person get to the root of the problem and fix their trike. If we get rude we get banned :lol:

[86trizinger]

Either way.. Thanks everyone one for their input.. But due to some things coming up I may have to sell all of my trikes.