Need Idle help on an SX

[Tri-ZNate]

I have ajusted the idle screw to both extremes, played with the air mixture screw and the stupid thing still wont idle. It doesnt even try to idle. Does my carb need cleaning?

[Maine_Triker]

I have ajusted the idle screw to both extremes, played with the air mixture screw and the stupid thing still wont idle. It doesnt even try to idle. Does my carb need cleaning?

Probably, or maybe fuel isn't getting to the carb (petcock problem perhaps).

[Tri-ZNate]

I dont think its that since it will stay running as long as I give it throttle, BUT the moment I let off it dies.

[Pigga]

clean the air filter its probley just choking

[Tri-ZNate]

I went through, and through that filter with an air hose so it looks brand new now. And I'm running no air box lid and the mixture is still making my plugs turn black.

[mad_max]

Clean the carb throughly! Disassemble it, soak it in Chemtool or other cleaner and blow it out with compressed air.

[Tri-ZNate]

I might get around to it tonight. I cant do it today since I'm gonna be starting a new job so I'll let you know what turns up when I clean 'er

[asc180]

Check your choke cable and lever assembly make sure the choke isn't on a small amount. i had that problem before.

[Dirtcrasher]

Remove every single jet and get it spotless inside and out. It will also never run right if the oring on the airscrew is bad or it got turned in to hard and the tip of it is not perfect anymore. I have even seen the tips pitted. You may not notice until you hold it next to a new air screw. If your running no air box lid then you need to re jet, from the air screw to the needle jet and the main jet.

[Tri-ZNate]

If your running no air box lid then you need to re jet, from the air screw to the needle jet and the main jet.


Where can I get some bigger jets for it? I was thinking about getting a 350x carb and slapping her on there since it will fit.

[MO350X]

Chances are, it's the original and in dire need of cleaning up.
The kits are CHEAP and the carbs are SIMPLE.
Don't let it scare you.

Wait until you rebuild the carb. to do a re-jet!

If you try and jet a carb that is in need of a rebuild, you'll only be chasing your tail and get pissed off at the trike.

JETTING NOTE: If after the rebuild the trike runs okay on top WITHOUT the jet change but still won't idle, the needle position controls idle and off idle SO you may only need to fatten the bottom end by dropping the needle position one click.

[Tri-ZNate]

Chances are, it's the original and in dire need of cleaning up.

If you try and jet a carb that is in need of a rebuild, you'll only be chasing your tail and get pissed off at the trike.



I've tore into the carb 7 or 8 times so I know it doesnt need a rebuild, and to insure it doesnt need cleaning again I put an inline filter between the gas tank and carb.

[MO350X]

I've tore into the carb 7 or 8 times so I know it doesnt need a rebuild, and to insure it doesnt need cleaning again I put an inline filter between the gas tank and carb.

Let me rephrase that:

Did you put a rebuild KIT in it?

Just taking it apart and cleaning will not do the trick if there's a bad needle, gasket, o-ring, pilot screw, damaged needle, etc., etc..
And if you did put a kit in it, how long ago?
Kits are dirt cheap and they work wonders every time I've used them.

I just hate to see people chase their tail trying to make a bike or trike run right. I know how frustrating it can be.

Just food for thought.

[Dirtcrasher]

Where can I get some bigger jets for it? I was thinking about getting a 350x carb and slapping her on there since it will fit.

If your running no A/b lid and an exhaust then a X carb will be a nice upgrade, otherwise just clean up the SX carb and jet it for the extra air coming in.

I've owned 6 250SX's and the airscrew is almost always the weak link. Last time I bought a kit it didn't evn have the dam float needle which is what most of these older carbs need. But it does have the air screw and oring which in itself is cheaper than from the dealer. Nothing usually wears out in carbs except for rubber parts.



Here is a copy of a post I made about a year ago......




Your carburetor is FINE!! Carb cleaning 101..

In case you wanted to know....

Ive had like 3 people leave me there toys lately for bad gas problems or they think they need a new carburetor - I'm no expert, feel free to add to this but I just wanted to share my experiences. Just keep your fuel clean, run an inline filter and don't leave gas in there over the winter and you will avoid most problems. Clean your trike and the carbs outside before you start removing it.I use a well lighted table away from everyone and everything - a white rag to lay everything out in order is helpful along with a manual.

Rebuild kits are generally just orings, jets sometimes, gaskets and a new air/fuel screw. These screws if overtightened do get bent at there tip and bad gas eats the brass - either one will stop them from working correctly. There are no other magic parts in a rebuild kit.

Make sure you completely remove EVERY single jet (they are all just threaded in - no cheap screwdrivers on the brass!!), needle valve, air screw etc and clean them each by themselves in gas and then carb cleaner. Then you leave the carb body immersed in gas before you go at it with the carb cleaner. If your mother yells at you for cleaning with gas, forget the gas part. Put the plastic extension on there and completely soak and squirt through every single passage etc - the carb should be naked of all moving parts and pieces. Carb cleaner in your eye really really really hurts so I'm just warning you. Compressed air is very helpful but a good can or 2 or carb cleaner blasted through also works and evaporates quickly. I use a qtip in the larges passages but even 1 strand of cotton left in any air or fuel passage will screw it up. The constant spraying of cleaner eats the most gunk. No wires or drill bits as they scratch the jets holes and this can upset the air/fuel balance - these holes are thousandths of an inch in diameter. You don't want to see one spot of anything in any inside portion of that carburetor.

When removing air or fuel screws first slowly and lightly thread them all the way until they bottom out - counting the number of turns and the original "o - clock" position they were at. Then you can back them out and clean up in there and just reinstall them and back them out to there original setting. Look in your manual just to compare that setting - 1.5 turns out actually found at 5 turns out could be part of your problem. If it does not respond correctly try the stock setting but remember that even the air box lid removed or a dirty air filter affects this setting.

Behind some screws you may find a washer, oring, spring, spacer etc etc, but just pay attention and look in there before you toss it in the bowl of gas and you see a washer fall out - at which time you panic wondering where it belongs in the carb. Jets don't get a "turns out" setting - they just thread in and tighten against the carb body or another piece of a jet or spacer etc. Jets are just hunks of brass with a bunch of holes in them - not anything like plutonium or an atom bomb.

For the most part I have never seen a worn out carb, I have seen stripped or damaged carbs but most all carbs can be saved and have no problems other than dirt, missing or damaged orings and or improper setting. Anyone buying carbs on EBAY to remedy there "broken carb" probably just needs a little TLC.

Good luck

[Tri-ZNate]

Let me rephrase that:

Did you put a rebuild KIT in it?




The previous owner did like a year ago.

[yater]

Your pilot jet has crap in it or varnish stuck in there