2010 EC300 Factory Jetting Specs - WTF?

[Jakobi]

Originally Posted by Bailey28

The idle issues for me have been fixed with a combination of different things.

Float height: I had to lower my floats about 2-3mm, just so gas doesn't drip out on the sidestand.

Needle diameter: the stock needle, 2.705mm in diameter passes too much fuel at idle. The 300 pulls a lot of vacuum due to large displacement and if you could measure intake manifold vacuum at idle it would be more than a 250 and more than a 200cc bike.

The #7 slide I have is notched at the center bottom and lines up with the needle jet block shroud creating even more vacuum in that pocket where the needle sticks out of the needle jet orfice (emulsion tube).

I believe that the pullover from the thin needle contributes to the rich idle condition. Think about it. When the motor is cold it may idle fine but after you ride for a few miles and it heats up, it idles really low or just stalls out.

So with the throttle closed, a thin needle, higher than necessary float height, the massive vacuum signal from the 300cc of displacement, and the notch in the slide along with a hot engine that doesn't need as much fuel at idle, yeah, I think the recipe is there for a hot no-idle situation.

I think folks may have sucess fine tuning the pilot jet, needle diameter and air screw. I didn't want to spend the money on a #8 slide as of yet.

The K and L diameter needles ran fine in my bike when the temps were in the 50-60 degree range. At 90 degrees, I needed a thicker needle so it would idle again.

I have to back Bailey 100%.. Same setup on my bike.. N1EF would not idle at all hot. I went to an N3EG which had to pull over a bit. Today I dropped in a N3CH and once again the idle circuit cleans up even more.. This is all with a 38 Pilot. I think if I went to the J I may need to step back to a 40 pilot..

Good work mate, couldnt have explained it any better myself

[rod]

I found this link on this site some time ago, it's the most comprehensive info i've found on keihin needles http://www.sudco.com/vol33/135-136.pdf

Wish there was something similar for the N3-- range of needles, the best i've found is in a yz 250 owners manual, it says a N3EH is richer on straight section than a N3EJ and that a N3EW falls in between the pair of them, but it doesn't state what the actual diameter's are.

The final letter indicates straight section diameter, but it obviously doesn't follow alphabetical order?

[husley]

2010 300. Just switched from a n1ef to a n3ch: went for first time quick ride today-bike has come alive . Sorry, pilot/main settings written down at home.
Will update as i put on more miles this week

[Jakobi]

Originally Posted by husley

2010 300. Just switched from a n1ef to a n3ch: went for first time quick ride today-bike has come alive . Sorry, pilot/main settings written down at home.
Will update as i put on more miles this week

Yewww!! look forward to the updates!

[Jakobi]

Originally Posted by rod

I found this link on this site some time ago, it's the most comprehensive info i've found on keihin needles http://www.sudco.com/vol33/135-136.pdf

Wish there was something similar for the N3-- range of needles, the best i've found is in a yz 250 owners manual, it says a N3EH is richer on straight section than a N3EJ and that a N3EW falls in between the pair of them, but it doesn't state what the actual diameter's are.

The final letter indicates straight section diameter, but it obviously doesn't follow alphabetical order?

Stolen from elswhere

SIZE: P/NO Dia.
NOZF 13383-37EB0 2.705mm
N1EF 13383-37E60 2.705mm
N0ZE 13383-37EA0 2.695mm
N1EE 13383-37E50 2.695mm
NOZD 13383-37E90 2.685mm
N1ED STOCK NEEDLE 13383-37E40 2.685mm
N0ZC 13383-37E80 2.675mm
N1EC 13383-37E30 2.675mm
N0ZB 13383-37E70 2.665mm
N1EB 13383-37E20 2.665mm

seems to indicate f=2.705mm E=2.695mm D=2.685mm and so on...

..so
G= 2.715
H= 2.725
W=2.735
J= 2.745

[mtothef]

spent the day at hollister yesterday playing with jetting. between 500-1000 above sea level, about 65 degrees. i've got 178 main, and i think 38 pilot, stock N1EF needle on the #1 clip. really like the way it runs as is, although there's nowhere for me to move the needle if i go above sea level or if it gets hot. also, i noticed a couple lean sounding clattery noises when doing half throttle plug chops.

so i started by raising the needle one notch at a time, just to see how it felt. about all that seemed to do was soften the transition into the powerband and make the throttle response more sluggish. it didn't get blubbery or load up down low, the half throttle rattle went away, and the plug got more chocolatey than tan. did that up to the 3rd clip, then put in the N3CH needle.

N3CH is noticeably thicker than stock, and about a half a clip shorter in overall length. i started on the #3 position, right in the middle of things. and left it there. plug is tan on chops, there is no half throttle crackle anymore, low end seems a bit more healthy (seemed to be comfortable running a gear taller at low throttle settings and still had more throttle response from idle into the beginning of the powerband), feels like it maybe is pulling a bit less violently as it comes into the powerband.

i really like the way it runs right now. it feels very healthy down low and very crisp across the board. mighty fun!

there was some talk about idle and vacuum a few posts back, and i noticed that once the fatter needle was in there, my bike was idling faster. nothing else had been touched, aside from the needle being replaced. i ended up backing the idle screw out about a half turn, then playing around with that and the air screw to get it sort of in the ballpark. air screw is now two turns out, used to be one turn out. before, it would idle when cold, and then die off and become inconsistent when hot. seems to idle a bit better now, although i wasn't spendng much time focusing on that. didn't do any idle speed chops to see if i am rich or lean yet either.

[husley]

Mine idled much higher as well. I am at 4-6000' mid 50's F.

I have the needle one clip down from the top, going to try second clip down today and see what the difference is

I believe I am running a 40 Pilot and 180 main......I think

[mrfallover]

Originally Posted by husley

Mine idled much higher as well. I am at 4-6000' mid 50's F.

I have the needle one clip down from the top, going to try second clip down today and see what the difference is

I believe I am running a 40 Pilot and 180 main......I think

That sound fat on the main, I am at 5000ft mid 50-60 and running a 175, 40 pilot, N3EH 3rd position from top, it was rich and just switched to a 172.

Steve

[Jakobi]

Originally Posted by mrfallover

That sound fat on the main, I am at 5000ft mid 50-60 and running a 175, 40 pilot, N3EH 3rd position from top, it was rich and just switched to a 172.

Steve

I have settled in with the 38 Pilot, N3CH#2, 175 main, AS 1.5 turns out.

I noticed the bike will still idle even with the air screw wound right in now where it used to drown out in fuel. Been a while since I've done any plug chops.

I have considered moving to a 172 main to get some more over rev but keep playing it safe with the 175.

[husley]

Originally Posted by mrfallover

That sound fat on the main, I am at 5000ft mid 50-60 and running a 175, 40 pilot, N3EH 3rd position from top, it was rich and just switched to a 172.

Steve

This (my 180 main) might explain why the bike does not have the top end I thought it would.