Jetting/tuning question

[singletrack]

So I've been elbows deep in my 82 1100ES for about two weeks. Re-jetted the carbs with stage 1 dynojet kit (only used the needles), clip @ third notch from the top. Replaced the mains with Mikuni 117.5s. Adjusted the valves, set the idle mixture w/ highest rpm method and synced the carbs with a homemade manometer.

I only rode it a short while tonight, basically just down to the c-store for fresh gas. The bike idles just fine, but somewhere between zero and 1/4 throttle the bike hesitates bad. I can get off a start all right, but right about where you want to give it the dinner it just bogs hard. When I crank the throttle past that point it surges and takes off like a bat out of hell, but each gear shift hesitates at the same point.
Except for that hesitation point it seems to be running pretty good. I have noticed some minor popping, but need to run it more to know if its on decel or under power.

Any ideas?

[posplayr]

So I've been elbows deep in my 82 1100ES for about two weeks. Re-jetted the carbs with stage 1 dynojet kit (only used the needles), clip @ third notch from the top. Replaced the mains with Mikuni 117.5s. Adjusted the valves, set the idle mixture w/ highest rpm method and synced the carbs with a homemade manometer.

I only rode it a short while tonight, basically just down to the c-store for fresh gas. The bike idles just fine, but somewhere between zero and 1/4 throttle the bike hesitates bad. I can get off a start all right, but right about where you want to give it the dinner it just bogs hard. When I crank the throttle past that point it surges and takes off like a bat out of hell, but each gear shift hesitates at the same point.
Except for that hesitation point it seems to be running pretty good. I have noticed some minor popping, but need to run it more to know if its on decel or under power.

Any ideas?

What pipes and air box are you using. The intake has the biggest impact to jetting than anything else.

Does it pull to redline?

see the factory pro CV tuning guide.

http://www.factorypro.com/tech/carbtun.html

[singletrack]

Its a stock airbox with a K&N filter, aftermarket pipes 4 into 2, they're shorter than stock and hi-flow. I haven't had it anywhere near redline yet, just up and down main street near my house. I'll take it out again tomorrow and check.

[singletrack]

When I had adjusted for highest idle yesterday I ended up about 4 turns out on the air screws. So this morning I tried readjusting, ended up closer to 3 turns out. The bike still ran poorly (considerable hesitation) at low rpm (2-3k) or 1/8 to 1/4 throttle. It does pull hard all the way to redline once I get past that throttle point. I did also notice a lot more popping on decel with the new air screw settings (leaner) than yesterday, and the bike didn't seem to bog quite as hard as yesterday either.

[niclpnut]

Hey, I was having the exact same issue.

Finally got my ES just about right.

Use the smaller air jet from the dynojet kit. Your stock is 180. Use the dyno 160 (It's 160 something if i remember right).

Thats going to quickly improve your pilot circuit.

Your probably about right on your mixture screws. I had to go closer to 4 out with pods and a 4-1 to get it where it needed to be.

Also, you might need to go with the slightly larger pilot. Stock for you is a 45 pilot. You might need the 47.5 size pilot.

Just try the main air jet first, then if it's still abit lean at around 1/8 throttle, get the larger pilot.

[singletrack]

Thanks for the reply niclpnut. Glad to hear your bike is running well I checked my jet kit, the pilot air jets are 160's. The stock pilot air jet is 170 for the 82 ES (it's 180 for the '83.) Assuming that's what is in there, I didn't check them. when the carbs were off. Makes sense though, it does seem to be running lean on the bottom end. Guess I'll have to wrestle those carbs out once more!

[Katarat]

Unbolt the battery box and take the bolt off the top of the air box. It just gains a little bit of room but it helps a lot. Slide the carbs to the right and remove the throttle cable & put them back the same way

[BassCliff]

Hi,

Do a plug chop right where it stumbles. Have a look at the plug. I'm thinking you might have to raise the needles if it's too lean right there in the midrange.


Thank you for your indulgence,

BassCliff

[singletrack]

@katrat thanks for the tip sir, I will give that a shot. Haven't unbolted the battery box before...

@basscliff definitely a possibility. was thinking about the fact that the pilot circuit ran fine before I changed the needles and main jet. There was some popping on decel, so I think it was a bit lean before, and seems more lean now. Could be I have a leak around the carb boots, I'm going to make sure this isn't the issue before I do any more jet changes. If everything is tight, I'll try the plug chops and see how it looks. I've got 47.5 pilot jets on the way, and also have the smaller 160 air jets on hand, so plenty of options to try when I do get the carbs off again. I'm just not sure yet if the stumble is happening on the pilot circuit watch or the needle jets...been raining cats and dogs the last two days, so hopefully I can get back at it soon.

[niclpnut]

i also had to raise the needles up one notch to even out the transition of the pilot to needle circuit.

Nic

[singletrack]

Good to know, thanks again Nic!

[singletrack]

So I'm still waiting for parts, but I did fiddle around with the bike a bit tonight and last night.

I called Dynojet just for giggles yesterday, and they said to cover the filter 1/4 with duct tape and see if that helped. If so, then raise the needles 1 groove. So I tried that out and sure enough, this helped the stumble at 1/8 throttle quite a bit. Still a slight hesitation but a definite improvement. It still idled rough too but I didn't futz with the air screws given it was just a test.

So tonight I raised the needles one slot and replaced my air jets with DJ 160's from my kit. The Mikuni's in there were 160 (stock is supposed to be 170, PO must have already swapped em.)

Since the DJ 160's only convert to a 150 Mikuni, I wasn't sure it would make a big difference, but I figured what the heck. The guy at dynojet said the air jets in my kit would lean out the bottom end, which just didn't make any sense to me...am I missing something? Smaller air jet = less air = richer mix, no? He was also appalled that I didn't follow the kit instruction and installed 117.5 mikuni mains. I'm leaving them though, the mains work just fine.

Waiting on the 47.5 pilot jets to get here from Z1, mine are 45's and stock. I may just throw those in too before I put the carbs back on. Also checked the float levels, they were all good.

[niclpnut]

I was slightly confused about the air jet size also. smaller =less air= richer not leaner...

I've still got a bit of a burbling at cruise and some lean plugs after chop at 1/8 throttle. no hesitation and no surging however.

Going to try and figure out how to test fuel level as I still think my floats (even though set about a mm higher for more fuel) might be off some, as I'm Still lean down low.

Let us know how the adjustments come out.

Nic

[singletrack]

she's BAAACK!

So the raised needle/bigger pilots/smaller air jet seemed to do the trick. She's running much better now. Only thing is she's popping like hell on decel. I've got a colortune coming so I'll see if that can help. (On the air screws, once I get a couple of turns out it doesn't seem to make much of a difference on rpm's.) But all in all I'd say the current setup is a success. Plugchops will tell for sure, but I just finished and it is dark and cold, so tomorrow more tweaking & testing.

Here's where it stands now:

dynojet needles (DNT406) 4th clip from top
Mikuni 117.5 mains
Mikuni 47.5 pilot jets
Dynojet 160 air jet (DH160)


This is all on a bike with stock airbox, K&N hi-flow filter and aftermarket pipes.

I'll post again if further tweaking leads to any substantial changes. And yeah, there's a ride in my very near future.

Thanks for the help everyone.

[niclpnut]

When you put the aftermarket exhaut on did you change the exhaust gaskets?

also check for possible gaps in the tail pipe, midpipe or header connections.

Could be causing the popping or your still lean

Mine was popping abit due to a gap in the midpipe/header joint.


go go plug chop~!

as you said they will tell the story.


Nic