A bit of confusion on some jetting issues..

[TheCafeKid]

On my 1100ES, KN pods, SuperTrapp header and can, which I really had no apparent problems out of last year, aside for some popping back thru the pipe on decel which i had pretty much lived with.

Here's the deal: Couple nights ago after getting home i yanked the carbs because i was having issues with the bike feeling like it was loping, or dropping a cylinder sporadicly. This could be sync i know, but the thing also wreaked of gas, like she was way rich at and just off idle. I took the carbs apart, cleaned them as well as i could without soaking. There was IMO no need to soak em as she's been running for a month or so now, and ran all year last year with no problems for both me and the PO, another forum member. Anyway, i found some sediment collecting in the bowls, cleaned them, blasted all orifi with carb spray, and air, assuring that everything was coming out the other end as it should, steve helped me remove a stuborn adjustment screw, and we put em back together and put em back on the bike. Power response is a bit better now, but it STILL wreaks of gas, and after warming up acts as tho its drowning. (blipping the throttle when simply warm is very concise, snaps on and off, but once hot the bike sounds very sluggish to respond)

Here's the set up:

135main
45pilot
STOCK needle (this is part of the transition problem i know, but to me it should be going more to the lean side than rich, so i dont think this is part of my actual problem at the moment)
adjustment screws at 2.5 turns out

Any ideas guys? Yeah yeah, i know i know, get a Dynojet kit, but i feel like i can lick this with a set of Dynojet needles i have and some stock mikuni jet changes, and save me some money.

 

[jetta90]

Be aware of the pilot jet size. I don't know what stock pilot jet size is on your bike and I am aware you are running a header and less restrictive air filtration system.
The pilot jet will affect the larger throttle openings in the carburator system as well.............needle valve, jet needle, main jet.
All this to say you may need leaner pilot jets..........
Turn the "adjustment screws" out only 2 turns and work downward from there. So.......turn them out only 2 turns and see if it helps, then try again at 1.5 turns, and again at 1 turn etc until you see some changes.
The adustment screws you are referring to adjust both fuel and air on the CV carbs. By leaning the mixture out (2 turns, 1.5 turns, 1 turn out etc) you are removing some of the fuel metering at idle............and since the idle system (pilot jet) also effects fuel delivery in the upper throttle positions, you are also leaning out the complete fuel range.
The adjustment above will give you an idea only, and will only compensate a little for a too fat pilot jet. Ideally, you would have a proper sized pilot jet but this will tell you if you're rich.

 

[TheCafeKid]

Be aware of the pilot jet size. I don't know what stock pilot jet size is on your bike and I am aware you are running a header and less restrictive air filtration system.
The pilot jet will affect the larger throttle openings in the carburator system as well.............needle valve, jet needle, main jet.
All this to say you may need leaner pilot jets..........
Turn the "adjustment screws" out only 2 turns and work downward from there. So.......turn them out only 2 turns and see if it helps, then try again at 1.5 turns, and again at 1 turn etc until you see some changes.
The adustment screws you are referring to adjust both fuel and air on the CV carbs. By leaning the mixture out (2 turns, 1.5 turns, 1 turn out etc) you are removing some of the fuel metering at idle............and since the idle system (pilot jet) also effects fuel delivery in the upper throttle positions, you are also leaning out the complete fuel range.
The adjustment above will give you an idea only, and will only compensate a little for a too fat pilot jet. Ideally, you would have a proper sized pilot jet but this will tell you if you're rich.

Appreciate the input. However the 45 pilot is STOCK size. This is part of whats bugging me. All things being equal, with the needle NOT corrected, and the pilot being stock, i SHOULD be on the lean side of things. However, plug readings show otherwise. Not black, actually not bad at all really, but this is also a bit backwards IMO. Again, it SHOULD be a tad lean, and it isnt. hence my confusion. The bike is what appears to be rich, it stinks of gas at idle, and the pipe throws soot all over the swingarm and shock. I know that the Main will also affect everything as well, but 135 isnt that far of a throw from stock. Still dunno what gives...

 

[Baatfam]

I'm probably way off base, but could your petcock be failing and putting gas into the vacume line on #2?

 

[TheCafeKid]

I'm probably way off base, but could your petcock be failing and putting gas into the vacume line on #2?

I suppose its possible, but ive removed the tank umpteen bazillion times over the last couple of weeks doing various things and its never once given the indication that its not working correctly. Never leaks a drop pulled..

 

[Baatfam]

I suppose its possible, but ive removed the tank umpteen bazillion times over the last couple of weeks doing various things and its never once given the indication that its not working correctly. Never leaks a drop pulled..

But there was no vacume applied then, correct?

It just seems to me everything was fine and now its not, so what changed?
What is failing?

 

[TheCafeKid]

But there was no vacume applied then, correct?

It just seems to me everything was fine and now its not, so what changed?
What is failing?

Well i wouldnt say it was FINE exactly, but certainly not as bad as it seems now. The pipe always sooted a bit, and it popped on decel, which *I* actually assumed because it was lean. Maybe i will give a .5 turn back on the screws and see what happens. It still doenst make sense to me tho. The ONLY other thing that i could think is that perhaps a float valve or valves is/are starting to go and its letting in too much gas.

 

[hampshirehog]

If I've read this right you think should be running weak on the pilot and needle circuits and you think the mains are about right, though not much of an increase above stock. Plug chops are ok.

Have you got a Colourtune to see what's actually going on inside?

To me the obvious things to check are float height, the pods aren't clogged and that the choke system is functioning correctly. If everything is fine my next step would be to look at the valves - clearance and inlet timing. If she's closing too early she'll spit fuel back like an over-egged 2 stroke.

The mains won't be affecting the lower parts of the circuit - you can run around all year on partially opened throttle with no main jets and not notice it.

 

[mriddle]

Swap the tanks with ED and rule that out quick.

But there was no vacume applied then, correct?

It just seems to me everything was fine and now its not, so what changed?
What is failing?

 

[TheCafeKid]

I'll do that but i seriously doubt this is the issue.

Valves were adjusted about a week ago, as well as verifying the timing on the cams was set correctly. ( I double check it every time i adjust valves because im paranoid bout one day having a faulting auto tensioner and skipping a tooth or two) So thats not it.

Spoke to Chef bout it just a bit ago on the phone, and i have a couple of things to check out before i go stripping carbs off again. It occurs to me that recently i had a charging issue due to crappy connections that have since been cleaned and was reading 15v at the battery at about 3.5k, and since, i havent had a charging issue. HOWEVER, that isnt to say that the battery isnt having an issue, or that im getting crappy current to the coils/plugs. I am going to rule this out before i go stripping the carbs off again, because, as ive said, by all rights i should be lean, not rich. Having said this, *I* still get the feeling that its in the jetting set up, im just not sure how. Bill (Chef) seems to think my 135 main is "way to f-ing big" and suggests i drop to a 130 main, 45 pilot, using my Dynojet needles that i was lucky to procure when i bought an 82 11E parts bike for my GS11/Bandit/GSXR project. He suggests setting the clip at about 3.5 from the bottom, and 2 turns out on the screws. Seeing as how he nearly blew his bike up playing with jetting, and has since got his machine running tip top, I will give it a shot. However, I dont think the main being to large is relative to my smelly, sluggy problem....Any of you carb gurus out there, please, feel free to interject.

 

[gearhead13]

Those jets seem to be on the lean side to me. I am running a 47.5 pilot and 137.5 main on my bored out 750 with 34mm carbies.
Are your floats operating properly? Adjusted too high?

 

[TheCafeKid]

Those jets seem to be on the lean side to me. I am running a 47.5 pilot and 137.5 main on my bored out 750 with 34mm carbies.
Are your floats operating properly? Adjusted too high?

Are those Mikuni or DJ measurements? They're different. And, depending on what you're bored over, I would bet you actual dollars you're way rich. Might take a wiff of your oil and take a look at your piston heads thru the spark plug hole, because that is HUGELY different. Chef is running essentially that same set up on a 1168 kit 1100... And again, Im not lean, im rich at the moment. The exhaust stinks of unburnt gas, its throwing soot and its suffocating on gas...

 

[gearhead13]

Ok, fine SORRY I tried to help. My bike is actually a little lean on the main.
DUH! Does dynojet make a 137.5??????

 

[TheCafeKid]

Ok, fine SORRY I tried to help. My bike is actually a little lean on the main.
DUH! Does dynojet make a 137.5??????

actually I think they call it by even numbers (138) now that you mention it. Sorry, wasnt intended to be snarky at all, just matter of fact. In your sig line you say it has a DynoJet Stage 3 kit, hence my question as to the measurement. Ive actually been contemplating your set up there, and I suppose your large jetting could be the product of using carbs of that size on a motor of that size. With a bigger throat bore, it draws more air, needing larger jets for more fuel, etc etc. Im not claiming to be a carb guru by any stretch, (obviously not or i would not be asking the original questions i have..lol) but Im just not understanding the need for such a large set up on a moderate bore kit. Im interested in your reasons, and no, im not trying to be a d!ck. Ive got some mods intended for my 1100ES, simple, easy things like 1150 cams and such, so any imput and ideas i can get from people, and their logic behind them, im always interested in.

 

[rustybronco]

TCK, the only thing I could suggest is to run tubes from the drain screws up the side of the carbs and see what the actual fuel level is. I sounds like there is an issue with the needle and seats not seating or the needle valve hanging in the bore of the seat, or float(s) that is/are becoming saturated.
also weak springs in the fuel inlet needle. I know that won't occur over night, but it is still something to ponder.

but, at idle, and slightly off of idle, your nose is telling you something, it's too rich.

food for thought...