2010 Jetting Saga Continues

[Jakobi]

So today I went at it.. Sorry I didnt bring the camera along. I'll take the bike out tomorrow with the cam running as a demo.

I tried needles and pilots and more and more.

N1EG#2, then #1. Too rich off the bottom. Pulling over and having to use a smaller pilot to compensate. Racing idle when leaned out enough.

N3CH
#3 Wouldn't rev past 1/4 throttle smoothly. Blubber blubber.
#2 As described. Vibey and slow to rev but sounding clean
#1 Wild.. but too lean to run safely.

N3EJ (with pilots 38, 40, 42)
#2 Wouldn't pull clean past 1/4 throttle.
#1 38P high idle after opening the throttle. Lean pilot.
#1 40P dialed in. Quite smokey when cold. Pulls so cleanly. Idles well
#1 42P runs well when dialed. Very very smokey. Big smoke on decel even at full temp. Will also idle but a bit on the fat side.
All on #1 absolutely crisp from 1/8th - 3/4th. Felt to sign off/too lean on the top.

End result some 8 hours later after much tinkering, head scratching and trying things multiple times.

40 N3EJ#1 178. Weaponary! wicking it up off idle in the tight stuff almost put me into a tree once or twice.. When on band its in a world of its own.. Today has been well well worth it!

[rod]

Duckman probably wasn't far off the mark when he posted this on DBW in december 2010......

"We ran a stock 2010 EC 300 this year in the Vic off road series ( and 2 modified ones) the bike ended up 2nd in expert open. Russell would off won the year had he not been a no show at the last round while he was overseas. The bike was box stock except for a FMF TC muffler, Dirtworks Suspension/Main Jet Motorcycle modified (harder) forks and the shock had the oil changed, thats all. We used the N3EJ (Yamaha) needle on the 3 rd clip, 42 pilot and 175/178 main. The air screw will settle at about 1and a half to 2 out. The other 2 bikes had head squish modifications which require richer jetting".............


The richer settings they are running on the unmodded bike as opposed to Jake's setup can possibly be attributed to the miserably cold and bleak climate they have in Victoria (southern Australia) as opposed to beautiful sunny Queensland where Jake and I live.

For those outside Oz that don't understand all this, Duckman has a strong allegiance to Scotty's dirt bike spares in Victoria, one of Australia's most helpfull GG dealerships and they know their product well. Victoria is roughly 2000 to 3000 kilometres south of Queensland depending on where in the state you are.


PS: Beautiful and sunny now that we're over the cyclones and flooding.

[Jakobi]

Couldn't have said it better Rod. I have always wondered why the southern guys have always ran richer. I would seriously like to be able to run the needle in clip 2 but the bike becomes all but unridable. It really is that bad. The 178M is more of a safety precaution than anything with cooler times ahead up here.

I'm really excited about taking the bike for a run through my test loop tomorrow! Will post up the vid.

How is your bike running?

[rod]

Originally Posted by Jakobi

Couldn't have said it better Rod. I have always wondered why the southern guys have always ran richer. I would seriously like to be able to run the needle in clip 2 but the bike becomes all but unridable. It really is that bad. The 178M is more of a safety precaution than anything with cooler times ahead up here.

I'm really excited about taking the bike for a run through my test loop tomorrow! Will post up the vid.

How is your bike running?

Have not tinkered with jetting for a long time now, got a bit fed up with it really. I'm still on the gas guzzling 40/cek #2/178 set up, but as i said on another site it runs strongly and idles well albeit with a slight lull just above idle when you 1st crack the throttle.
I have a CEL needle that i want to try ( I've not ridden the bike since 3rd April due to back problems), but i will try this needle within the next couple of weeks. At the same time i'm following closely what you guys are finding with the N3-- needles.

PS: 2010 ec 300 Nambotin, PWK 38 with 2x screw's in cap.

[mrkartoom]

Good to hear you have it sorted out. I just need to get my pilot figured out, but mine runs great elsewhere with the N3EJ on #2 and the 180 main. I'm at fairly low altitude and it has been a bit cooler, so that may explain why I'm clean at richer settings.

I'm going to ignore the smoke at bottom end and go bigger on the pilot - back to a 42 and see if that cleans up the bog I get just off idle and the idle/air screw issue. Comparing my other settings to yours 1 step richer on the pilot would be consistent with the other differences. It's 80, dry, and sunny here today, so I'm slipping out of work early and doing some testing.

[jeffs2200]

2011 xc 300 38mm

elevation is 0-1000' 90 - over 100 degrees.

I was running

n3ch #3
178 main
38 pilot
as 1.5

The bike seemed to run great like this in the colder months but with the heat and humidity we are having I have been having lots of trouble getting a consistent idle. Air screw seems to not have much effect. I could set the idle and then ride around a little and it would fall back so low it would barely stay running.


I changed to

n3ch #2
178 main
40 pilot
as 2 turns.

so far this seems pretty good. I only rode up and down the street, but the idle is good and the air screw seems to be having an effect. I will report back after I do some more testing.

[Jakobi]

I could probably run a 42 pilot too if I wanted, with a few more turns out on the air screw. I found the air screw didn't have an overly pronounced effect on the idle speed (definately not like the idle screw does).

Method I used to dial it in was I back out the idle screw until I reached a low consistant idle. I then began moving the air screw out half a turn. Blip the throttle into the mid range and then listen. Depending on how the revs fell back to idle I would know which direction to turn. Essentially I wanted to be just rich of a hanging idle. If I turn it out on the AS another half and blip the throttle I will notice the bike hang above idle for maybe 2 seconds, before dropping back down into its chug chug chug rhythem.

I think alot of the excess smoke was just from running at idle for a while, and putting around the yard. At a guess I'd imagine once in the bush and running harder for longer the smoke will all but disappear.

http://www.youtube.com/watch?v=iAaGDAph4d0 Here was a bit of my test run. Doesn't show anything WOT or even half throttle really but you can get the idea of how clean the bike pulls from idle.

[mrkartoom]

Sounds like it's chugging along pretty well. I didn't get a chance to play yesterday evening like I hoped, so I'm hoping today when I get home. So of all the settings you have tried [ 40 N3EJ#1 178 ] is your favorite so far?

[Jakobi]

Originally Posted by mrkartoom

Sounds like it's chugging along pretty well. I didn't get a chance to play yesterday evening like I hoped, so I'm hoping today when I get home. So of all the settings you have tried [ 40 N3EJ#1 178 ] is your favorite so far?

Yeah its very similar to the 38 N3EG setup I ran prior to tinkering around, just a bit cleaner right off idle as expected with a leaner diameter. I am going to step up to the 42 pilot today to try and bring the air screw into play some more. The needle is definately best in position 1 for me. Its clear when riding that 3 won't push past 1/4 throttle. 2 will but its burbling through. 1 is clean right through. Plug chop indicates tan at 1/4-1/2 throttle load.

The 178 Main is just a bit of a safety buffer while doing this testing. Our mornings have been getting cooler aswell so might keep it like this until summer.

Going to go and put the 42 in now, and ride the test loop again this afternoon.

Update: 42 is on the money. Idle screw and air screw both functioning at full temp. The bike was super smokey from warming up on the stand but once taken out and ridden properly (even in single track) the smoke cleared right up. No hanging idle at all. You beauty!

[Bailey28]

I ordered an N3EH and an NOZH today. I am anxious to get them in the mail and start experimenting again for the hot weather.

I also found a post on trimming the jet shroud nozzle screen, the part that sticks up into the venturi. I had this done by Ron on my old KDX carb and it cleaned up the 1/8 throttle burble.

I may try to shave 1mm off the screen height, it is supposed to lean the mixture in this area the same as if you changed to a # leaner slide.