2010 EC300 Factory Jetting Specs - WTF?

JP4

JP4

New member
I posted before about a new 2010 EC300 that I recently took deliver of. I've had a chance to plow into the carb and here are the factory settings:

Slide: #7
Needle: N1EF - Top clip (leanest)
Main: 175
Pilot Jet: 40
Air Screw: 5 1/4 out

WTF? Kinda seems like they just bolted on the carb as it came out of the box from Japan with no thought as to set-up for the bike or where it was going. The needle clip and air screw settings make no sense.

Based on my searches on this site and my locale (600' ASL, average riding temp 20C) I think it's way lean. I've ordered a needle (CCK, it seems a popular choice), and some fatter main and pilot jets. Won't really be able to ride the bike for a few months, as it's pretty much full on winter here at present.

Does it sound like I'm on the right track regarding the jetting?

Jason

Otherwise, I'm super impressed with the bike and can't wait to ride it for real -I'm thinking a trip to Georgia or Florida this winter is gonna be must!
 
jetting

my 2010 300 came very similarly jetted, all over the map. It was mighty lean at sea level. Raised needle and fatter pilot and its ok jetting wise. Soon to try some needles to remove crazy lean flat spot in mid-range...

cheers,

Rick
 
My 2011 300 had the same settings, except the airscrew.

I do not find it to be lean at all. I had to go down to a 38 pilot because it was loading up on bottom. I may try a leaner needle and fatter jetting. I think I am going to try the N3CH from my KTM with a 40 or 42 pilot, 3rd clip and maybe try a 178 main and see haw that does.
 
Jeffs. I think you will find the N3CH right on the money with the 40 or 42 pilot. I am running an N3EG in mine. The CH is a half clip leaner, and a step leaner on the 0 - 18th opening.

I have N3EG#1, 38 Pilot, 175 Main. 100M - 500M, 20-30C, 60-100% humidity. Absolutely hauls. Smooth crisp responsive oodles of power from right off idle.. Truely transformed the bike!

Fuel consumption went from hitting reserve at 90km (after adding an extra L of fuel) to 110km reserve off the 9.5L tank.

I wish they all came jetted like this from the factory!
 
Jakobi said:
Jeffs. I think you will find the N3CH right on the money with the 40 or 42 pilot. I am running an N3EG in mine. The CH is a half clip leaner, and a step leaner on the 0 - 18th opening.

I have N3EG#1, 38 Pilot, 175 Main. 100M - 500M, 20-30C, 60-100% humidity. Absolutely hauls. Smooth crisp responsive oodles of power from right off idle.. Truely transformed the bike!

Fuel consumption went from hitting reserve at 90km (after adding an extra L of fuel) to 110km reserve off the 9.5L tank.

I wish they all came jetted like this from the factory!
Click to expand...

Man o man ... so many needles ..... I've plowed through needle chart comparisions, but without any real time on the bike I'm just guessing.

Ordered a CCK caused it seemed middle of the road ... I think ... trying to get my head around the tapers and lengths, diameters ... not to mention effects on PJ ... eyes glossing over ... how did I ever get through law school?

I read about the KTM needles (N3CH/G et al) but wasn't sure. Maybe too much info ... Who's prepared to venture an opinion and say that they are better or worse for the 300 Gasser at an elevation under 1000' (300M) ASL?

It's a mystery to me so any opinions on the N3 needles would be appreciated.

Guess I'll just bolt up what seems like a reasonable set-up and use that as my base point - I think for 15c (someday it'll be warm!), and 250M ASL this should be safe:

#7 slide
CCK needle -3rd clip
40 pilot
178 main
1 1/2 air screw

Cheers,

Jason
 
jeffs2200 said:
I have the N3CH 3rd clip, 40 pilot, 175 main.

I will test Sunday and report back.
Click to expand...

Good luck. Don't be afraid to move the clip up one on the trail just to evaluate.

I found my bike would burble on clip 3, runs well on 2, but 1 was just even better again. So clean and crisp!
 
I tried the n3ch 3rd clip, 40 pilot and 175 main. Airscrew about 1.5 turns out.

500ft asl temps around 50degrees F.

The bike starts good and runs crisp from the first crack of the throttle. It has quite a bit more snap than with the n1ef needle. It seems to rev out better as well. I may try a 178 main and see if that makes any difference as well. It felt like it may be able to use a little more fuel up top. When you hit a long straight at wot then back off it would make a little noise, or surging. Very little but enough to make me think it could use a little more fuel.
 
jeffs2200 said:
I tried the n3ch 3rd clip, 40 pilot and 175 main. Airscrew about 1.5 turns out.

500ft asl temps around 50degrees F.

The bike starts good and runs crisp from the first crack of the throttle. It has quite a bit more snap than with the n1ef needle. It seems to rev out better as well. I may try a 178 main and see if that makes any difference as well. It felt like it may be able to use a little more fuel up top. When you hit a long straight at wot then back off it would make a little noise, or surging. Very little but enough to make me think it could use a little more fuel.
Click to expand...

Glad to hear it was a positive change. It'd be interesting to see the results of going to clip#2 with a 178 main.

I found the N3 needle really cleaned up the whole rev range.
 
I will try the larger main first and see what that does. I will then try clip#2 and see how it goes.

The bike pulled really well and did not feel rich at all.
 
Makes me wonder why I have to run mine on the top clip to get the nice crisp response. Could be something to do with the 30C and 70+% humidity here in the tropics. Your needle is a bit leaner than mine.

I have also read of people using the current yz250 needles with good results. N3EJ/H, which is only half a clip difference than the one you are using.

When will you have some video up Jeffs? ;)

I'd also be interested in knowing how it stacks up against your KTM in the engine department.
 
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It is not a real fair comparison to the KTM. My KTM has a Slavens ported cylinder, and an sx head with a procircuit platinum2 pipe. Trying to remember how they stacked up stock is kind of tough.

The KTM has way more hit than the GG 300. I really like the smooth power delivery of the GG. I do prefer the way that KTM has the tuneable powervalve via springs and the adjuster dolly screw. I ran mine with the red spring and the dollyscrew out flush to the cases which is the most aggressive setup. I am a big guy so that helps tame the power. I let some of my smaller friends ride my KTM and they can not see how I race it in tight woods like that. They seem to prefer the more mellow power of the GG.
 
Sounds like a weapon! This is my first 2 stroke so haven't really got anything to compare against, however I wouldn't weigh any more than 80kgs geared up so find the GG just about right.

Its pretty dull to ride on the wet setting.
 
I am running the N3EH needle and everything seems fine and crisp, brown plug, no spooge out the exhaust, but i only get about 70km on a std tank. This is generally slow tech riding, but just seems a bit heavy on juice.

what are you guys getting on a tank (mix ratio of 40:1)
 
I managed to get 110km before reserve last ride. Wasn't very much in the tight and technical, more muddy and rutty. Still alot of on and off the throttle, and when I was on it I was on it hard. Probably most time on the pipe the bike has seen yet, and the best fuel economy, however I'm running on clip #1, at clip #2 I hit reserve at 95km. I'm also running a 38 pilot and a 175 main.

My plugs are nice and tan all over. loads up a bit if left idling too long.
 
If you don't want to spend too much time jetting, the other option is a JD jet kit...his kits are pretty close if not spot on.
The kit comes with the necessary jets, high and low altitude needles, good jetting directions and tech support with a phone call.
The good thing about a kit is the research and testing is already done and everything you need is in one kit.
Just a suggestion
 
A big +1. For a 250 anyway this is as good as it gets. I can let my bike idle leaning on a tree while I help one of my kids if needed.
 
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