2010 Jetting Saga Continues

[Jakobi]

Special thread for a special bike

So of late I have been chasing up some annoying excessive vibration as the revs drop after a lick of throttle while stationary in idle. The vibration is present in both feel and audibly. I had just chased down the power valve thinking it may have been at cause but its well in spec.

My bike had previously been running N3EG#1, 38 Pilot, 175 Main. Which was nice and crisp but still a bit fat right off idle. A slight burble when rolling on from closed.

I went to N3CH #2, still with the 38 Pilot and 175 Main. The bike was definately slower to rev off the bottom, although sounded cleaner. It felt like it wouldn't rev really fast, but it wasn't bogging or hestitating. Just not pulling as hard or fast as it should be until later in the revs. Suspected slightly rich until clearing and coming strong onto the main.

Today I lifted the clip N3CH #1, same 38 Pilot and 175 Main. My god! Cracking the throttle right off idle was tearing up the lawn. Out onto the street and I was struggling to get the rear end to hook up on the slightly moise bitument. 2nd gear right off idle, a quick flick of the wrist will have the front end skyward. The bike feels almost like it would be too much to handle in the dirt. Its incredibly crisp and responsive and pulls really strong through to the pipe limit. The vibration as the revs drop also feel to have been reduced alot. Much less evident than they were. Bike also idles really well. Still blows a bit of smoke right off the bottom even opening the throttle while the engine is hot.

My main concern is that the bike will be too lean. I worry because everyone else is running these needles at clips 2 and 3, even with the 36 mm carb. My bike has the PWK 38mm ASII. Elevation approx 300m most of the time. Temps in the mid 20's. Humidity varies day to day.

I guess I will have to find some time to do some partial plug chops and see what stories they tell. What is everyone elses opinions? I have ran the bike with N3EG at clip 1 for over 1000kms without ill effects. N3CH at clip one is half a clip leaner again.

Perhaps I'll try the N3EJ I have at clips 2 and 1 to grasp a feel. I have some video of the bike on the stand which I will try and post to help.

In others experiences, will fattish jetting cause an increase in engine vibration?

 

[mrkartoom]

Like I posted in the WTF? thread I had the N3CH-3 in there with those same jets. Like yours mine made no power down low and would not rev quickly, and blowing lots of smoke. I wanted to go to clip #2 and lean it out with those same jets and then maybe back to a 35p if it was still rich, but I diverted my attention to my faulty clutch and never did. By the time I figured out the clutch my N3EJ showed up so I switched to that.

I did do some more testing with the N3EJ this weekend. I'm starting to wonder if I have something else going on. With the following settings it was blowing smoke off the bottom, but making great power. It also acted a bit lean in the mid range - as I verified by opening the choke a skosh.

N3EJ-3
42p
180m

So I raised the needle to clip #4 as planned and also dropped the pilot to a 38. That was too rich everywhere now, so I'm thinking WTF? Was my previous test off? I decided to go back to clip #3 and leave in the 38p.

N3EJ-3
38p
180m

It's still too rich everywhere and blowing smoke even in the mid now, where it wasn't last test on the same clip even with a smaller pilot. I'm getting confused and frustrated, so I try the following:

N3EJ-2
40p
180m
a/s - 1.75

Now this is good.

After I run it for a bit it seems to clean out and runs really crisp mid to top. Power down low is good, but not quite as good as it seemed when running rich on the 42 and N3EJ-3. Very weird. It's very close though. It still blows a slight hint of smoke up to 1/4 throttle, but this could be a fun setting to ride. I have to try a 38p next as at times it seems to bog right off bottom, but it is not consistent.

The problem is, as I have found on other settings, is that my a/s does next to nothing and the idle is erratic. I drop the idle as low as I can to test the a/s and adjusting it in/out the idle doesn't change until it's almost closed. I just set it to where it feels like it revs the best off bottom. Then the idle is also frustrating. I get it set where I want it and ride. When I stop and go to neutral the revs are way up. I back the idle off just a wee teenie skosh and it wants to die, so I put it right back where it was and it's back to normal. Ride & repeat.

p.s. I'm starting to wonder if the RB Mod could be in my future. It's supposed to address some of these same issues I'm having. I'm concerned that I can't correct for atmosphere with this thing the way it is, or maybe it just doesn't show up at closed throttle.

 

[Jakobi]

I have also heard that excess squish can make these a bit tricky to get just right off idle.

I'd rather have a needle in clip 2 than very top just for peace of mind more than anything. I only run my ratio at 50:1 so maybe i'll move to 40:1 for some extra lube and that should lean the jetting enough to make clip #2 just right. Its very frustrating indeed.

 

[Jakobi]

My bike has been idling really well, air screw adjustments work, pulls strong.. wild strong No spooge, less vibrations.. My main concern is that I am running what appears to be a lot leaner than other people are.

In saying that a friend in the same area with a 2011 EC300E 38mm PWK is using a 35 pilot. Not sure what needle, but he also had to lift the clip up to get it right. I might ask him more.

His bike vibrates very little in comparison to mine, and it was the short ride I had on his that made me realise just how soft my bottom end had got since changing from the N3EG.

Its weird because the leaner jetting feels much crisper and snappier and happier to lift the front end with a flick of the wrist, but the richer jetting feels like it will continue to pull alot better when stuck on the side of a hill. Ideally I'd like to find myself somewhere between the 2 clip positions.

 

[mrkartoom]

I have also heard that excess squish can make these a bit tricky to get just right off idle.

I'd rather have a needle in clip 2 than very top just for peace of mind more than anything. I only run my ratio at 50:1 so maybe i'll move to 40:1 for some extra lube and that should lean the jetting enough to make clip #2 just right. Its very frustrating indeed.

I'm also at 50:1 (RelRay H1R) and going to go to 40:1 next mix. I was reading some info on Maxima's website about oil migration that GMP posted up in another thread. I went with 50:1 after my dealer convinced me, but was slightly nervous about it. For our use I think 40:1 is the way to go and it may be better for these N3EJ settings as well.

I'm still gonna compare whatever I get to the N3CH. I was thinking clip #2 would have been enough. I'd definitely check the plug for clip#1. Sounds like you could be dialed in very close. You can always get it running good then throw in the next size main for some protection. We need dynos.

 

[Jakobi]

Yeah we need dynos

As mentioned I always ran the N3EG at #1 and haven't holed the piston or seized it up. It was very abrupt transition from the rich pilot circuit onto the lean needle that made it hard to ride in the lower revs.

I think N3CH#1 being a half clip leaner is really pushing the limit. I want to have a safety buffer for cold mornings/days with winter just about to tee off here. I think next few days I'll slap the N3EJ in at #2 and check back with my feelings and comparisons. Can get a needle change, warm up, and test ride done in about 20mins now. I'm thinking the N3EJ #1 could be what I settle for yet.

 

[mrkartoom]

My bike has been idling really well, air screw adjustments work, pulls strong.. wild strong No spooge, less vibrations.. My main concern is that I am running what appears to be a lot leaner than other people are.

In saying that a friend in the same area with a 2011 EC300E 38mm PWK is using a 35 pilot. Not sure what needle, but he also had to lift the clip up to get it right. I might ask him more.

His bike vibrates very little in comparison to mine, and it was the short ride I had on his that made me realise just how soft my bottom end had got since changing from the N3EG.

Its weird because the leaner jetting feels much crisper and snappier and happier to lift the front end with a flick of the wrist, but the richer jetting feels like it will continue to pull alot better when stuck on the side of a hill. Ideally I'd like to find myself somewhere between the 2 clip positions.

If you're down on power then you probably are on the lean side. That's the problem with this thing 1 clip position is too much of a change.

My dealer jetted my bike with a 35p, but that was with the stock N1EF needle. I ended up at clip 1 with that too, but it still didn't run good. Be interesting to see what your friend has with that pilot.

 

[mrkartoom]

That sounds about right. About 5 minutes for the needle and the rest to ride test. 5 more minutes to pull the drain and change jets if needed. This thing is a dream to jet compared to the BST on my old LC4. Only took me about 200 hours to make a fire-breathing beast out of that.

 

[Jakobi]

I have a feeling it might be an N1EE that he is using. But that doesn't make sense to me. He did say one needle leaner than stock. So maybe N1EG? I have one of these on hand too.

I think that N3CH#1.5 would be perfect. #2 is strong but doesn't pull fast enough. In saying this N3EH#1 would put me right here. Braap braap.

You seem to feel that I'm going too lean and losing power, but I don't think it is. I find the leaner I go the better it gets. Just gets harder for me to put it to the ground without closing the throttle I think.

N3EG#3 wouldn't even run in my bike. I would get to mid range and just burble on the spot. #2 felt much like the N3CH does now. It revs through but in a kind of slow tame dull way. #1 rips through the mid generally with the rear tyre spinning.

I think the more I write and the more I think about it I'm convincing myself that I'm on the right track. Be it just my bike is a freak, or where I'm located I should stop worrying about what others are running and be happy with my results.

 

[mrkartoom]

You mentioned the power difference on the hill climb, so I'm thinking that maybe you are on the lean side. Maybe it shows up more when the engine is really loaded? Maybe you are right on the edge. 1 clip position seems to make such a big change.

1/2 clip sounds like the trick. Don't they make little washer/spacers to do this?

 

[Jakobi]

You can buy the little washers that you slide under the clip to lift the needle just a bit more. Shim it up. I don't have any on hand though.

The difference between the N3C and N3E is half a clip also.

I should probably mark my grip and see if I can dial in if the sluggishness off the bottom is the pilot or the needle. Quite possibly the overlap of the both.

My problems on the hills weren't so much the bikes in ability to chug. Just that when the revs would get down to my fat pilot from N3EG it would be a bit rich. Showing more throttle snapped it onto the needle which ran like a raped ape. Essentially I was constantly transitioning in and out of wheel spin.

I think even a 1/4 of a clip position makes a substancial difference, as I can definately feel the change between #1 and #1.5 (N3Cx#2).

The richer oil ratio might be just enough to give the bottom a little bit more that I'm looking for.

 

[Bailey28]

I just came back from my weekly ride at a rock garden. I am running:

BGL clip 5
38 pilot
180 main
a/s 1 out

Bike runs great at low revs, pretty strong, but not as strong as the stock needle right off idle. However the engine runs very smooth and clean. Gas mileage is fantastic, and there is no spooge at all, only a light grey ring.

I did take out the reed spacer and it seems to hit sooner. In the woods it is fine but on the road (I have a plate) The bike struggles to get onto the pipe in 5th and 6th gear. It may be just that its only a "300" against the wind at 55mph off the pipe. If I really twist the throttle it will get on the pipe and take off.

I would like to try the N3 taper to see what you guys are stoked about. Jakobi, so you went from the N3EG to the N3CH, in essence a half clip leaner and one step leaner on the straight diameter from G to H?

With the Sudco aftermarket needles, an "L" is equal to the factory "F" diameter. A factory "H" diameter is equal to an aftermarket "N" diameter.

The weather is hot here, 90*F plus, so I figured I could jet leaner and the motor would be happy. I may try the stocker N1EF clip 1 with the 38 pilot.

I am also 200 feet above sea level.

 

[Bailey28]

If I can figure out how to put up the spreadsheet comparison here, it will freak you out how much the BGL clip 4 is equal to a N3CF here.

 

[mrkartoom]

Can you do a screen shot to an image file? You might have to host it somewhere to get a link to it.

 

[Jakobi]

If I can figure out how to put up the spreadsheet comparison here, it will freak you out how much the BGL clip 4 is equal to a N3CF here.

Its really hard to compare a triple taper needle to a straight taper.

I'm looking at the spreadsheet now and to try and match the 38, N3CH#2, 175 you would have to run something along the lines of Pilot 40 BGL#3.5 Main 200. Even with this you'd be 8% leaner at 1/8 throttle and about the same from 1/4th through to WOT.

 

[tnttimber]

Do me a favor and try a 48 pilot with that N3EJ in #2 with a 180 main. My bike would never run right with the lean pilot settings Ive read everyone on this forum running. I kept going up on the pilot and everything kept getting better, power, vibration, air screw operation.

That N3EJ is a yz250 needle and the yz settings use a 50 pilot in that bike.

Try it you might be surprised.

My bike is a 2010 250 sixdays and I ride around 3000-5000 feet.

 

[mrkartoom]

Do me a favor and try a 48 pilot with that N3EJ in #2 with a 180 main. My bike would never run right with the lean pilot settings Ive read everyone on this forum running. I kept going up on the pilot and everything kept getting better, power, vibration, air screw operation.

That N3EJ is a yz250 needle and the yz settings use a 50 pilot in that bike.

Try it you might be surprised.

My bike is a 2010 250 sixdays and I ride around 3000-5000 feet.

Strange you say that as my bike had much better power down low when running a 42 pilot compared to the 40, but that was at clip 3. It was blowing lots of smoke. I'm on clip 2 with the 40. It's also strange at your elevation you have gone up with the pilot. I don't think I've seen anyone that fat down low. Hey I'll try anything!

 

[tnttimber]

You might try a 45 pilot before you go to a 48 since your bike is a 300 and mine is a 250, ussualy you need a litle smaller jets on a 300.

The N3EJ needs a fatter pilot than the stock needle by a couple of sizes. I ran a 42 or 45 with the stock needle, so still much fatter than what everyone else seems to be running.

My exact settings on the 250:

Main-180
PJ-48
Needle-N3EJ #3
air screw- 2 turns

My bike rips.

 

[GMP]

What slide are you guys (with the same size carbs) running? If the slide is rich you can screw with needles forever and never get it really good. It will also mess with your pilot ckt as you have to jack the idle screw in. Try a leaner slide and by all means get the squish dialed in when you can. 300s are more touchy than 250s and these details are even more important.

Also, you should jet with the map switch in the hi or sun mode (more advance).

 

[Bailey28]

BGL clip 4.5 compared to a N3CF clip 1. Same as a N3CH except for the diameter. Just to show the fuel curve differences, which are very minor. +/- 5% max. The black reference line is the stock N1EF clip 1. It is hard to compare the triple tapers, but low to mid is where everyone complains about. Most all of the needles run pretty hard once the bike is well onto the pipe.