2011 ec 300 stalling at low rpms with JD jet kit

[gassybill]

hi guys.

2011 ec 300. brand new piston and rings. riding in victoria BC right now 20-25c at 0 to 1000 feet ASL.

Started out with the shitty stock needle N1EF with a 178 main and 42 pilot. it ran ok in cold weather. but still not great. always stalled out at low rpms.

I have a recluse clutch that may be affecting things

I got a JD jet kit. I installed as per their directions. 40 PJ 180 MJ and red needle at clip #4. the bike idles better and the idle screw and air mix screw actually do something now.

What hasnt changed is the fact that if i roll onto about 1/8 throttle then let off the gas as if to roll over a little bump the bike stalls.

If i open up the throttle and continue to WOT the bike runs great. but i ride tight single track and i need good strong low RPMS

Here are the combos of the JD jet kit that i have tried.
with 180 MJ and 40 PJ ive tried Red needle clip #4 JD recommended start
Blue needle clip #2
Blue needle clip #3
175 MJ 40 PJ Red#3 clip
Red#2 clip
i always start with the airscrew 1.5 out and go until 2.75 out.
None of these combos seem to make a difference as far as preventing stalling
the recluse seems to be set right bike tugs a tiny bit at idle in gear.

any advice? has anyone had this problem? i cant keep crashing my bike because of stalling at these rpms, shes really starting to take a beating

 

[gassybill]

A good wrench i know has suggested that i push my clutch pack apart further with the slave cylinder on my rekluse.

ill try that and update

 

[gassybill]

No luck with recluse adjustment

 

[gassybill]

Also tried 178 mj 38 pj red clip 4. Exact same

 

[Neil E.]

Try a 42 pilot and increase your idle speed by turning in the stop screw.

 

[barbotte]

I am no expert but I was told that the needle does not do anything at low speed but the main do ..I would try 38 or 35 .or your clutch need adjustment ..try again but hold the clutch handle to see if it die .cheer

 

[gassybill]

I have tried the 42. no real change except the idle screw doesnt really work.
The bike has kind of a 2 step idle. idles really high until i put it in gear and let clutch out. then it pulls a tiny bit like it should. ive tried adjusting the clutch screw from all the way in to all they way out. it just changes the rpms that the clutch engages at but doesnt change my problem.

getting pretty frustrated at this point.

 

[barbotte]

here is what i was told
"At 1/4 throttle the main is not in use, the main jet usually kicks in at 1/2 (half throttle). So if you want to go leaner at 1/4 you have to play with the idle jet and needle (the needle barely is in play at 1/4 if at all).

However even if you go a tad leaner on the idle jet (let's say a 38, witch i am using in the summer with the JD kit even tough they recommend the 40) i don't think there will be a noticeable increase in mpg."

here are my setting now
450 ft elevation
blue needlle-- second clip
175 jet (i dont have 172 on my kit as i have (165--170--175--180)
38 jet
1.25 turn
seem to run good at slow speed
cheer

 

[gassybill]

Are you riding a 300?

 

[Jakobi]

1/8th throttle isn't much to be rolling back from.

The high idle in neutral and the low idle in gear tells me you have quite a bit of clutch drag.. This will likely be the cause of the stalling.

Did the basket have any notching in the fingers? Can you set the recluse up to slip a bit more?

I've always aimed for to set my engines up to idle smoothly, but low in neutral (at operating temp). This tends to mean that it won't idle forever in gear with the added drag. It doesn't worry me as I don't have any expectation to idle in gear for extended periods.

Jetting wise, start with a clean carb and clear jets. Set the float to spec + 0.5-1.0mm more for the angle the carb sits in the chassis (it should overflow if tilted to the side just past 45 degrees). Set the slide nice and low to ensure you aren't pulling over and sucking too much air (helps get a consistent idle and easy starting). I start with a recommended setup. Adjust clip position for 1/4-1/2 throttle response. IMO most noticeable effect of the needle is right around 1/4 throttle. Adjust pilot using air screw to find where she starts and idles. Move to the main last and taper down to where you come from being a bit rich to strong.

The hard part is the off idle response. You have needle diameter/straight section, slide cutaway (notched/not), air screw, pilot jet, and float height all impacting on the balance.

If you have a poor vacuum signal or excessive squish clearance which can cause inconsistencies and you can chase yourself around in circles for eternity. Ask me how I know!

 

[gassybill]

thanks for the reply jakobi

I didn't realize that i may be better off not expecting it to idle in gear without dying.

Ive seen tutorials on checking squish clearance. ive always just hoped that i wouldnt have to do this on my bike but i guess its time.

I dont know how to check for a vacuum leak but ill see what i can find on existing posts.

i suppose correct order of operations will be to set the idle first, then the rekluse

 

[Jakobi]

If I had an auto clutch I'd expect it to idle.
Pretty much all OEM engines have excessive squish clearances; it's not Gas Gas specific.
I don't think you have a vacuum leak. Vacuum signal was in relation to the intake charge/velocity, impacting on the carbs ability to pick up fuel from the jets at low revs.

Make sure you always work with the engine at operating temp, a clear oiled air filter, fresh fuel, and a spark plug that is gapped correctly and not caked in carbon.

Get the bike to idle nicely in neutral as your first step. You want to be able to apply some throttle and have the revs drop back down and find the steady idle. Going leaner it'll want to hang and race for a bit. Too rich it'll flame out and stall.

Once you have it doing that nicely with the idle screw nice and low you can start bumping the idle up a bit to find the idle you require in gear, still paying attention to make sure your revs drop nicely.

 

[gassybill]

So it turns out that JDs jetting was pretty good.
My theory is that my auto clutch wedges were wearing out or were the wrong weight.

I replaced the 11b wedges with 12a wedges. i believe that the heavier wedges will let the engine spin a little faster before engaging and therefore will allow it to not stall.

On account of im not a great mechanic i was having trouble telling between my clutch issues and my jet issues. it was especially difficult when i was having both at the same time.

Bike isnt running perfect now, but its not stalling now, and its rideable.
next step is fine tuning.

Thanks to everyone who offered advice
Special thanks to Jakobi a fountain of wisdom

 

[Jim Cook]

Jakobi gives pretty good advice.
I use a 42 pilot on my 2011 EC250 with a 175 main until I get into a hare scramble in the cold weather. Then, I go to a 178. I don't use the JD kit, though. I've had lots of jetting situations and issues with the GasGas bikes, but I've never had a stalling problem from backing off the gas at low throttle settings.

To clarify on the vacuum leak:
A vacuum leak would be an air leak.
To check for a leak, have the bike idling, and then spray a flammable mist (starting fluid, etc) starting at the carb, and then working towards the cylinder. If you don't find a leak, pull the ignition cover and spray behind the flywheel/stator. Except for the cylinder base gasket, that is about it for possible leaks.

Good Riding and Wrenching to You!