2010 Jetting Saga Continues
 

Special thread for a special bike :D

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?

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. http://i11.photobucket.com/albums/a1...der/cloud9.gif 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. http://i11.photobucket.com/albums/a1...eadscratch.gif

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.

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.

My bike has been idling really well, air screw adjustments work, pulls strong.. wild strong :eek: 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.

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. :D

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.

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.

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. :D

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.

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?