Choke Making Idle Over-Rev

[Eagle]

Hi, this is my first post so sorry for any mistakes...

I have a 2009 Gas Gas Ec125R and have recently rebuilt the topend and when putting the choke back in the carbie, I noticed the thread was stripped... Now, even when its pushed hard in the carb, the idle is extremely high and I have to cut the motor straight away so it doesn't seize from over revving whilst cold... Can anyone help?? Its just getting worse... I went for a ride before it got this bad (Idle was still very high) and once it was warm/ ridden, the idle was back to normal and it wasn't running like it was choked up...
Please help??

[Zman]

See if you have an air leak in the base gasket or between the carb and engine. maybe something came loose or a gasket surface was not fully clean.

Maybe you can seal the choke plunger threads with a little epoxy or the yellow Teflon tape for oil. or just replace the choke plunger.

[Neil E.]

I believe the spring on the choke plunger holds the passageway blocked off. With the threads stripped the passageway is open which is equal to having the choke on. However if the plunger assembly is coming out from the carb, then there would be a big air leak causing the lean over-rev.

Looks like you need to replace the plunger assembly.

[Eagle]

Originally Posted by Neil E.

I believe the spring on the choke plunger holds the passageway blocked off. With the threads stripped the passageway is open which is equal to having the choke on. However if the plunger assembly is coming out from the carb, then there would be a big air leak causing the lean over-rev.

Looks like you need to replace the plunger assembly.

So away from my bike at the moment, but as I can remember, thread tape wouldn't fix it and it could lift right out so yeah, big leak... I will try epoxy it like Zman said when I get back home in 5 days and go from there.

I have also noticed, that the bike is Extremely difficult to start from cold... Would this be contributing to this or not?
30 hours ago it was pratically a new motor, and It has had 1.5 hours on fresh topend rebuild (after break in). Before the rebuild and a also during break in period and first ride, the bike was normal to start from cold (2-3 Kicks), but now I can barely kick start it... It has fresh fluids and I have tried moving up in heat range etc but it just doesn't want to start... After about 50+ kicks it may finally fire but this is ridiculous compared to pre-rebiuld. After it is warm it will start easy btw.
Thanks

[Neil E.]

If it needed the choke to start before your issues, I'd say that the failed choke is the problem.

[Eagle]

Originally Posted by Neil E.

If it needed the choke to start before your issues, I'd say that the failed choke is the problem.

So we sealed the choke and that didn't fix it.. We then noticed that the airbox had been knocked and it had made the clamp between the airbox and carb loose, so we moved it back into place and tightened the clamp. That seemed to fix it, but after warmup, I went for a ride to clear out the bike, and it started happening again... Does this mean dirty jets? Any help would be great.also, there is minimal play/slack in the throttle now...

[Neil E.]

Make sure the cable end is properly seated in the slide pocket. You have to pull the slide out to verify this. Also note that the plastic retainer has to index properly in the slide groove. This will be evident when you take it out to check.

Also make sure the cable jacket ferrule is seated in the top adjuster going into the carb. Also check that the cable ferrule seats fully in the throttle housing (twist grip).

[Eagle]

Originally Posted by Neil E.

Make sure the cable end is properly seated in the slide pocket. You have to pull the slide out to verify this. Also note that the plastic retainer has to index properly in the slide groove. This will be evident when you take it out to check.

Also make sure the cable jacket ferrule is seated in the top adjuster going into the carb. Also check that the cable ferrule seats fully in the throttle housing (twist grip).

Okay, I will have a look at this after work tomorow, the aduster is screwed all the way in on the throttle body so maybe the prev owner had some trouble as well?
After starting it today, I noticed that it would run, the idle slightly higher than normal, then, after about 5 seconds start to die... If you try and blip the throttle to keep it going it will go almost straight to high revs. To me that sounds like a sticking slide? When I have it out I will have to see for any wear..
Cheers

[Neil E.]

You may need a new throttle cable. Broken strands can drag and cause slow movement of the cable.

[Eagle]

Originally Posted by Neil E.

You may need a new throttle cable. Broken strands can drag and cause slow movement of the cable.

Okay, I'm away from the bike for a while now, but I will take slide out asap, and if there's nothing obvious there, I will clean carb, then probably suss out a new throttle cable. Cheers for the help by the way man!