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View Full Version : 250sx choke plunger problem - cable issue?



TheRealFatShady
12-22-2010, 11:03 PM
Can't seem to get my SX to be safely rideable. I believe it's running lean/air leak causing way too high of an idle. Wheelies when put in gear.

Choke plunger/cable seems to not be working right. Tried replacing it with another spare set (both cables are free to move when not in carb body)

Is it possible I'm not putting it in right? The plunger threads in straight, so it's not like it appears to be in crooked or part way.

I'd put my 350x carb on it as that won't be back together for awhile, but of course, that DOESN'T have a choke on it. (Pieces are MIA)

Might spring for a 250x carb I have or one from a TRX300, soon I'll have that full engine in it, but that carb was said to have had a problem as well.....:(

Thanks

ailll1
12-22-2010, 11:19 PM
When the plunger is out, does it move freely with the cable?
For you idle, I guess you tried to unscrew the idle screw to slow it down.
Did you try to change the adjustment on the top of the carb where it comes into it? Might be this adjustment that keeps the cable from going out far enough and holding the throttle slide open a little. Doesnt take much on idle to make it rev high...
I dont get why your said that your 350x carb doesnt have a choke on it...?

TheRealFatShady
12-22-2010, 11:23 PM
Yea, when I got my X, the choke components were missing. Just my luck.

And I recall adjusting the cable (throttle) to have the slide open a small amount as it was higher before. Could it be the gasket at the top, which covers the slide? Or maybe the intake oring on the head?

Both plungers had looked to move freely with the cables, also. Just not when put in.

ailll1
12-22-2010, 11:35 PM
What I normally do when I adjust the throttle cable on top of the carb is that I screw in the curved part until theres small loose in the cable inside the carb between where its connected and the top of the carb. That way, I make sure that the idle screw will have some effect.

Did you check if there was something blocking the plunger to get deep in the carb? Maybe its just clogged but its also possible that someone broke the plunger needle in there. They are known for having seized plunger...

I dont think your problem comes from an air leak but if you wanna make sure, just spray carb cleaner or starting fluid everywhere you think it might leak (When its running of course). If engine rpms change, you know you got a leak.

MrPretty
12-23-2010, 12:35 AM
My plunger was stuck on mine but I was able to get it out with a pair of pliers and clean it up, now it works fine. I also had a problem with mine idling too high, especially in neutral. When changing gears it would jerk really bad, especially from neutral to first. The front would lift a little bit, but not enough to call it a wheelie. It turned out that one of the bolts that holds the boot from the carb onto the head was striped and it was sucking air through there. After fixing the bolt hole with some helicoil it fixed my problem.