Hanging idle

B

BSM2

New member
Ec300 2013
N3cj #3
Main 178
42 pilot
Airscrew 0.5 turns
24degrees at sea level.

Bike riding great but is hanging above idle after riding wide open throttle. (Didn't do it before, only the weather is changed)
At half throttle or less it is perfect.

Suggestion: needle one clip richer?
However, next week i'm going to the mountains 500meter to 1500meters with 25degrees.
And i'm not sure what to do.

What do you experts things?
 
I would check for air leaks. You are really rich on your pilot circuit already. The needle wouldn't cause a hanging idle especially since you are pretty rich there too. Do you still have the handlebar mounted choke? Check to make sure it is seated properly at the carb. Make sure the carb is seated in the boots properly


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Throw a size or two richer main in there and see how it reacts.
Go a clip richer. See how it reacts.

But I also agree that the setting you have at the moment isn't what I would consider to be lean. You could have an air leak somewhere so its definitely worth while checking. Remember, a small air leak is going to pull more air at higher rpm leaning things out more noticeably at these throttle openings.

15hrs is a little irrelevant. I can go and loosen off the air boot on the back of the carb and that would just about do it in 3 seconds, regardless of how many hours are on the bike/engine.
 
Going to a higher altitude might improve things ( less air). Mine has been similar but I stopped at AS 1.25. Same jets, similar needle. What about a partially blocked PJ? Mines fixed by our momentary warmer weather. Good luck!
 
Pffff... Still not solved the problem.

Checked and cleaned the carb , intake and vforcd valves.
Replaced gaskets. Checked float height and gastank for vacu?m and stil hanging idle!!!! It drops to normale idle after 5 seconds. Regardles the needle position...

I'm i missing something?
 
I too have similar symptoms, but it's because I am rich in the pilot circuit. Try a leaner pilot; I bet that will fix your problem. Some people get a bit confused with rich/lean condition. The warmer weather is enough of a change to make it noticeably richer.
 
Bikes tend to lean out when worked hard. Go to a 180 main. Drop your pilot back to a 40 and open the air screw to about 1.5 turns and see how it acts then


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Problem not solved with 40/180 pilots. Regardles airscrew position.

Noticible difference: the idle screw is way more sensitive. Also i had to turn the idle screw more out. My feeling tells me that the pilot is correct now.

Idle is hanging when i ride 1/2 throttle our more.
Up to 1/2 there is no hanging idle.
What is noticed when slowing down on the gears, when dropping the high rpm, the pipe gives a 'tang tang' and a push forward. Just one ore two times.

Shall i raise the needle one clip?
 
Worth a try.

Otherwise, heres something a little left field. With a large squish clearance (inefficient) it's possible that excess unburnt fuel can take a while to burn off from the combustion chamber. I struggled with similar issues on my 2010 model which had 2.6mm squish. Machined the head and it was like a new bike.
 
I just dont get it.
Idle is strong, but whatever i try, the rpms are not droping to idle after riding 1/2 or more. Even when it is only for 100meters...

Also tried different needle positions today
 
okay, now writing from my laptop and not from my cell phone :)
After a lot of testing herewith a summary of results etc:

Problem: Hanging idle,
Starting from more then 1/4 throttle. Doesn't matter if it is offroad or road. idle will hang and drop after 5 to 10 seconds.

Carb Setting:
Played with idlepilot 45/42/40, mainjets 178/180 and different needle positions from N3CJ.
Everytime there was a significant changed running bike.
However whatever i'm trying, the hanging idle is stil there...

Sow there most be a leak or someting?
-sprayed starterpilot at running bike at carb etc, no reaction
-Cleaned carb and v-force reeds. There were closing perfect.
-New gaskets.
- Checked the float height. That one is horizontal with the carb housing.
- Changed sparkplug (old one light brown color)
- checked oilseal at flywheel side
- Checked choke cable
- checked vacuum at gastank
- 1.6mm quish, not ideal but cannot believe that is the problem.

So...What i'm i missing?
 
Can u video it for us? Just guessing here but What about the slide sticking on the way down? Might be gummed up or something. Try wacking the throttle a bit after a WOT run.

Maybe try lowering the idle screw so it just barely idles, or doesnt even idle, and try that.

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Didn't mentioned but have checked the play on the throttle cable and also after a wot. No results.

Idle is already as low as possible to force the bike the bike dropping the hanging idle a.s.a.p.

Tomorrow we will loading up for riding in the mountains.so have to ride with this problem.
Will video tape is, but can show you next week
 
My 2012 ec300 race will idle smooth all day with a 38 pilot with no fluxuations. I'm running a 40 pilot and my bike is doing the same thing as yours. Though it's not practical, I run the 40 comfortably knowing that I'm not lean and it's running a bit cooler. Maybe give a 38 a try. But please don't if your spark plug is already showing lean. That would indicate that u would have a different issue than what I've described. Did u mention your plug colours? Did u mention what elevation you're at aswell?
 
The GasGas engines seem to go against the established logic. For many years I have been studying and practicing on this and am very grateful to this forum. When I bought my EC 250, I spent some years struggling against instability idle and significant changes with changes not so large temperature and humidity. Searching this forum, I came to the conclusion that one of the reasons was the totally wrong Squish off. Talking to my trusted mechanic decided to check the measure and found 2.4mm. After correcting the Squish (1.00mm) I noticed a huge improvement in performance and also the stability of idling, however this same oscillation which you refer still remained. I tested numerous combinations of needles and jets, and came to the conclusion that in GasGas engines, excess fuel in idle circuit causes this problem, accelerated idle for a few seconds to fall to the ideal rotation. Today, I have a perfect idling, without any changes, but for this a correct fit is necessary that its bearish circuit is fully adjusted without excess fuel by adjusting air screw responding to minor adjustments, otherwise it is impossible from idle and their consequent fluctuations. My guess is that your problem is due to excess fuel in this circuit idle in my case the best combination was a richer needle associated with a higher pilot jet, and not vice versa.

Good luck.
 
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