Yet another jetting question...

[Brian VT]

My bike is still running great on my winter jetting (42 pilot) but the air screw is 3 1/2 turns out so I can't go any leaner for altitude or light air.
I decided to buy a 38 and 40 pilot jets. I put the 38 in and am at 2 turns out.
It has a sputter at the very start of turning the throttle. It gets a little worse on either side of 2 turns out.
It's fine through the rest of the throttle range.
I'm under the impression that a sputter (as opposed to a bog) suggests a rich condition.
I don't know weather to buy a 36, put the 42 back in, try the 40 ?

FYI: '03 EC300 euro, #7 slide, LTR -0- needle, clip on 2nd notch from the top, 178 main, Boysen "pro series" carbon reeds with @ 150 miles on them, new plug BR8ES, clean air fliter, dirty silencer packing, fresh fuel with Stabil and 50:1 Amsoil.

 

[widebear]

Why would you buy a 40 and not try it? I.M.O. you have allready answered your own question.

 

[Brian VT]

Why would you buy a 40 and not try it? I.M.O. you have allready answered your own question.

I'm flustered because the 38 seems to be rich. I hoped for some advice before I start chasing my tail.

 

[eff]

Before I put the LTR kit in my bike I was running a 38 pilot about 1.5-2 turns and it would sputter when going down the road sections with just a small throttle opening.

Last summer I had to drop the needle to compensate for the heat (seemed to load up at .25-.50 throttle) at the campout ride and the sputter went away.

Now I'm nunning the LTR jetting and my bike runs way better, and the power delivery is sweet. You are running the LTR kit aren't you?

 

[JoshP]

I grabbed the LTR kit and the settings were way to rich for my bike although the needle was perfect. I'm running a 35 pilot with the LTR 0 on the second clip from the top and a 175 main. This is what I found works on my bike though these setting are no where near a starting point should be. With that said I agree with Wide Bars throw in the 40 and see if it gets worse. At least that will give you a direction to head in and make sure that 38 is totally clean also, use a guitar string, metal wire anything that is tiny. One time I had this tiny piece of paper stuck in there because the dealer would label the jets with a sticker and it made the bike run like sh@t. Couldn't even see the thing it just was stuck to the inside wall.

 

[jeffd]

Hi Brian,
Well here I go responding to a jetting thread again. Am I stupid or what? And by the way, if anyone attacks me personally for expressing my opinion, I will request that the administrator ban you for a month - oh and since that's me, I am guessing he will agree..

Where are you at on your idle screw? How many turns out? What I have seen in the past, is that you start leaning the pilot more and more then the idle is turned up to provide more fuel via the main/needle jet. This condition is referred to as "pulling off the main" or "pulling over". I am guessing this is "where you are" - but there could be other issues (like a worn needle jet in the carb or the reeds need replacement, etc.)

From my experience, if you want to have greater sensitivity to the pilot circuit (which this carb has trouble with and which is one thing you are looking for for altitude adj, etc) - you want to get the idle screw further out and the slide down so that it is pulling more off the pilot circuit (relatively speaking) - since the pilot circuit is now providing a greater contribution of air & fuel - the air screw will be more sensitive to adjustment. My opinion - richen your pilot back up (maybe even to a 45), drop the needle one position, turn down your idle adjustment and start with your air screw at about 2 1/2 turns out....

If you want even more pilot circuit sensitivity and easier carb adjustment - I suggest you talk to Ron @ RB-Designs about his soon to be released "carb mods".

jeff

 

[Brian VT]

if anyone attacks me personally for expressing my opinion, I will request that the administrator ban you for a month - oh and since that's me, I am guessing he will agree..

lol. I respect your advice. I'll start over with Les' recommendations (178, 48, middle clip, idle screw out) and report back.

 

[JoshP]

JeffD when will you learn your lesson?

haha

 

[jeffd]

lol. I respect your advice. I'll start over with Les' recommendations (178, 48, middle clip, idle screw out) and report back.

Thanks for the vote of confidence, won't be sure if I deserve it 'til later - it sucks to lose a day riding tweaking things into shape...

Do you have alot of time on the bike?

Not sure you need to go all the way up to a 48 - the nozzle (and needle) wears shifting things as the bikes age; this is also why I suggested going leaner one clip position from Les' original spec.

Eric Kangas went to a leaner needle to compensate after his bike "aged"- if what I suggested doesn't work for you, I suggest you contact him.

Also sent you a PM with a few other details...

jeff

 

[Brian VT]

- it sucks to lose a day riding tweaking things into shape...
Do you have alot of time on the bike?

Yup. I'd guess 5K miles.
You're right, I don't have time to mess with it before Sunday's race. I needed to get some seat time in so I threw the 42 back in to ride last night. It's okay, just not quite perfect. I'll figure it out later.

 

[GMP]

Brian,

You can also try a leaner slide and go from there. After jetting three GG 250s, the '00 and '07 starting with a #7 slide seemed much eaiser to dial in than the '03 with the #6 slide. This is especially evident at idle and off idle, the '07 runs very clean and will idle in gear with a 48 pilot, and the screw is not cranked in excessivelly. The 300 is a bigger pump so maybe a #8 slide and go from there. Just a thought.

Many variables and tolerances come into play here, so absolute specs should be used as a guideline and/or starting point, not labeled good or bad.

 

[CACTUSREID]

Glenn, I second that motion! I've just gotten the jetting more or less sorted out on my 04 ec 300 that I just purchased. compared to my 01 300 that wouldn't idle with any more than a 38 pilot and about 2.5 turns out on the air screw the 04 seems very close with a 40 pilot and 3/4 turns out. this tells me that a 42 would work fine as well with a bit more adjustment if needed for altitude etc. but i have a # 9 slide in both bikes,and I'm really starting to believe that this alone helps to sort out any idleing/roll on issues as much as anything else.