N3EG - 1/8 stumble and lean 1/2 throttle

krazy

Gold Level Site Supporter
Hi,

I'm getting a slight rich condition at 1/8 throttle (but not too bad) and I've just done a plug chop at 1/2 throttle on a nice long 3/8 mile hill, see photo.

AS 1
40 pilot
N3EG top clip (leanest)
175 main
Motul 800 32:1
0-500ft 20c

The plug is light grey colour, definitely not tan or chocolate brown like we aim for. Is that too lean? I'm hesistant to do a WOT chop unless the 175 would be enough to richen it back up.

I can live with a slight richness at 1/8 throttle but I don't know about correcting a lean 1/2 throttle by using a richer needle and then having too much stumble at 1/8. So in my mind I am thinking a needle with richer diameter (leaner) but coming onto the taper sooner (lower clip pos) to fatten up the mid. Does that make sense or is it possible with N3xx needles? I thought they all had the same taper so all were about the same at half throttle.

Bike is powerful, 3rd gear power wheelies with 46t rear sprocket, no pinging.
 

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Leaner diameter needle.
Richer clip position.
Richer main jet.

Leaner diameter may require a richer pilot jet to maintain the idle mixture.

N3EH/N3CH/N3EW/N3CW
 
Leaner diameter needle.
Richer clip position.
Richer main jet.

Leaner diameter may require a richer pilot jet to maintain the idle mixture.

N3EH/N3CH/N3EW/N3CW

Great, will order some brass now and report back. Many Thanks.
 
small update ... while waiting for n3ew and 185 main I put the cck back in on 3rd clip with 182 main. Real rich until 1/4 throttle as expected. WOT plug chop is a light tan, a bit too light. I am concerned that the rich cck needle and 182 main is on the lean side. No one else seems to go that rich. Perhaps I can't even use a N3 needle unless I go to 190 main or something. Either I have a leak or the head and porting work is better than expected and flowing more than others.
 
I have been chasing jetting for months. I ended with 40p 180m and N3CH clip 3. It is pretty good across the board. Nice and crisp. It will still lean out a bit on a long uphill but it's not bad any richer and it gets blubbery.


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Last edited:
I have been chasing jetting for months. I ended with 40p 182m and N3CH clip 3. It is pretty good across the board. Nice and crisp. It will still lean out a bit on a long uphill but it's not bad any richer and it gets blubbery.

That's a point, I have been doing plug chops on a long hill, going 70+ by the time I shut her down. I suppose that gives it a lot of time to lean out, and not representative of a typical ride.

Your conversation with Jakobi a few months ago helped me decide to try the N3 needles so thanks for that. Hopefully the 185 main will be enough to keep things safe. Fingers crossed.
 
I tried doing plug chops and just never had any luck jetting that way. It's not "real world" riding conditions. If you really want to read your plug I think the most effective way to do it is after a typical days ride. That will give you an idea of how the bike is running as a whole. Just jet the bike where it runs good and doesn't bog or burble and then just go out and ride and enjoy life. I have friends that are so obsessed with jetting that they put a threaded bung in their pipes and use Air/Fuel meters to tune their bikes. Lol


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I've tried loads of different setups on my 2011 300 , and stuck with ne3w clip 2 40 p. 180 main the bike is fast and aggressive with a nice plug colour only thing is i don't need choke to start from cold , second kick , don't know if this is a problem as it runs and idles good ?
 
I've tried loads of different setups on my 2011 300 , and stuck with ne3w clip 2 40 p. 180 main the bike is fast and aggressive with a nice plug colour only thing is i don't need choke to start from cold , second kick , don't know if this is a problem as it runs and idles good ?


I don't have to use the choke in the summer either. Bike will sit and idle all day long. I have the same jetting except I use the N3CH clip 3


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Crank seal??

Just an update, I've got the n3ew installed, and after lots of clearing out it runs pretty good. But something wasn't quite right. Then I noticed I am losing some gearbox oil. I'm pretty sure that is what's happening anyway, possibly right side crank seal from what I can gather. Clutch cover is also weeping a bit. Probably why I have been chasing my tail. Never been into a 2T engine before so going to research that next. Sigh.....
 
Interested with this, I've got n3eg top clip ATM and it's still too rich. I've ordered an n3ch, can anyone tell me what clip I should start on?
 
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