My carb like small pilot jet... problem?

[knutte112]

Hi.

First of all, please excuse my bad english.

Got my self a 2013 ec300e couple weeks ago.

Normaly ride and race on a enduro modyfied 2015 crf250r.
Bought this gasser to practise more of hard enduro. Freeride hillclimbs etc.
2 strokes run cooler, less expensive, you know all this...

The bike got 60 hours on it, driven with factory jetting by a middle aged woman.
Yes you guessed right, power valves and axhaust was just an oily mess!

So, started with a good clean on all parts. Muffler repacked.

Bought the CCK needle then set the carbs float and started to play with jets.

Here comes my question: How small pilot can I safeltly use?

Started out with 42 (178 main), beacuse thats what everybody seems to use.
To rich was my thoughts.
Tryed a 40, little better, still rich at idle.
Went with a 38, and now I think i'm getting closer.

BUT, airscrew set at around 2 turns out, and it idles without choke after like 5 sec when cold started. Strange... we are around freezing point here in sweden right now... sea level.
2,5turns out and there is a small lean bog when cracking the trottle wide open, from extremly low idle.
180 main makes no differens to that.
But it runs great (air screw at 2 turns out). Can idle for a minut or two without building up. Screams like hell when twisting the trottle, even after 10min of trialriding around the house. No rich or lean bog. 1 to 3 gear have just a little rich burble at 1/8 trottle without load. Needle in clip 3 seems perfect, not burble but not voilent in power delivery. Main jet seems ok, makes more power with 175 vs the 180. But still the 180 had no rich burble, or exessive smoke. Will try 172, and see if I get more crisp and power in the future, but right now, there are plenty of power!

And no matter how much I turn the airscrew out, I can't get the idle to get erratic/fast or what ever you call it.

So, am I tuning the wrong way, or can something be wrong? Feels wrong to go even smaller on pilot jet. Or are people in general just running very rich for some reason? Spark plugs reading can't be done at idle right?

What am I doing wrong, when selecting pilot jet?

Please give me your thougts on this one.

Regards Johan

 

[webmaster]

You don't say where your idle screw is set - in cases like this - you have it cranked in so far that the pilot circuit is no longer effective. (this is usually the case with the stock jetting using a n1ef).

When changing the jetting over to the cck needle - you should have backed out the idle screw to get the slide down. If you don't do this, then the majority of fuel and air is coming from the needle circuit - making the pilot circuit less - so pilot and air screw have less effect. This condition is referred to as "pulling over". It is pulling over into the mid circuit when you should be using idle circuit - even right at idle and off idle.

jeff

 

[SwampGasser]

You don't say where your idle screw is set - in cases like this - you have it cranked in so far that the pilot circuit is no longer effective. (this is usually the case with the stock jetting using a n1ef).

When changing the jetting over to the cck needle - you should have backed out the idle screw to get the slide down. If you don't do this, then the majority of fuel and air is coming from the needle circuit - making the pilot circuit less - so pilot and air screw have less effect. This condition is referred to as "pulling over". It is pulling over into the mid circuit when you should be using idle circuit - even right at idle and off idle.

jeff

very good info. I learned this by trial and error, as it turned out, my throttle cable was too short and also stretched near carb holding slide up slightly. need to reroute cable to the back side of the fork neck making it seem longer.

 

[firffighter]

I ran my 300 with CEL and CEM needle, #8 slide, and 38 pilot with AS out 2 1/4. Those needles are leaner diameter than CCL. Most consider this too lean, but my bike ran perfectly with ultra smooth linear power delivery. Plug check is proof of lean/rich. Mine was always chocolate brown and put lots of hours on bike with zero issues.

I think you're close on your jetting and my guess is if you tried a CEL or CEM you'd clean up that 1/8 throttle blurble

 

[knutte112]

Yes, very good info.
Thanks!
On my way to my garage, to check that out.
What would a good starting point be at, in turns at the idle screw?

I still have a hard time believe this would be the problem, but I hope so.
I did not back off the idle screw when I installed the new cck needle.
But I had to back it out, while I was riding.
Like 2-strikes at very low ifle speed. Hate that "pull" or "drive" that 4strokes have at idle. Or more correct, that high idle 4-strokes need not to stall.

On the gasser the idle is set low, clutch pulled and in first gear, it idles.
But as soon as I thinking about to start slipping the clutch it stalles.

IF my idle screw is set too far in, wouln't the bike rev like crazy when starting with choke? Mine does not.

 

[knutte112]

Firffigter: could you get your bike to ping or run lean with 38 at idle by turning the AS?

One more thing about spark plug: that brown colour everybody talks about, when will it be appear? After couple of hours riding?

The shop plug test I have been doing doesn't show any brown. Except at the very bottom of the white insulation...

When the bike have been running at idle for a couple of minutes on a brand new plug, there is a light "wet" grey coat on the plug. But no brown...

 

[knutte112]

Ok, pulled the carb.
About 0,8mm gap at the very bottom of the troath and slide.
It looks small, and I would be surpriced if that's too much of a gap...?

Checked that the trottle cable was not binding or pulling the slide. Everything seems good.

Looked for some kind of air leak jet in the carb, I thought it might be dirt in it.
But as far as I see, under the slide are the only air passage?