needles all the way up, still getting white plugs...

[gsBert]

hi, me again.

so i have my needles all the way up (clip in lowest position of 5)
im still getting white plugs, ie: runnign lean.
this is after a plug chop from runnign 10 seconds at 1/2 throttle.

its a 1150 engine (stock) with 36mm slingshot carbs (semi flatslide CV)

my main is a 140.

screws are 2 turns out

nice light tan on the flosed throttle up to 1/8 chop though...

im thinking of removing the main jets to see if thats my restriction...
im also thinking maybe my floats are too high, not filling the bowls enough. could that affect it?

i get a lot of gray smoke when on the choke and it stinks, but nothing when idling normally and i cant see any smoke when riding...

[Scud]

Bert -- You have been so helpful to me, I wish I wish I could help you now. :?

Scud

[sisu1970]

Slingshots

Im running 34's on a 750e w/142.5 mains. Thats what came with my jet kit & 137.5 for stage 1. I would go up on the mains. Try bringing your screws out to 3-4 turns. My bike was to lean on idle at 3 turns out. Went 4 problem solved.

[RacingJake]

Try some 150 mains, might even pick up some power too

[Hoomgar]

Bert, are you using a jet kit or stock needles?

[mark m]

screws are 2 turns out

nice light tan on the flosed throttle up to 1/8 chop though...

Bert,

Try turning your mixture screws out 1/2 a turn or even a full turn and maybe go up a couple of sizes on the main. Light tan sounds lean on the pilot and the needles can't flow enough to cover for that. The bigger mains may help, as well, as you are getting to the overlap area between the needles and mains at 1/2 throttle. If your plugs are white, you need to add some fuel, pronto!


Mark

[Carter Turk]

I have the same carbs on my 1150 (1990 GSXR 36mm). I'm running 147.5 mains. Needles are fourth clip from top, pilots 32 up from stock 30. 2.5 on the air/fuel with K&N pods. The floats had to be leaned out from a suggested 14mm starting point to 17-18mm. The motor has MTC 1229 piston kit, and Falicon super crank , otherwise it's stock. It does have Pingel petcock. Maybe that could be an issue with pods if you're running a stock petcock. Not enough fuel getting through.

The jet kit is an old Dynojet with super blunt needles, don't know if they all look like that. I have a Factory jet kit as well for this carb and the needles look totally different, tapered to a point.
But they didn't work in the used carbs I bought. Fouled dozens of plugs.

Also the slides had nylon hex plugs in the bottom with holes inside. I recall you mentioning having one blocked off. Both of mine are open per carb.

I don't know if this is a factor, but the GSXR carbs sit about 10-15 degrees at an angle to the intake manifold in stock form.

I had to fabricate some crude support to hold the carbs up, not at that angle, but somewhat level. I blew two or three carb boots off before I supported them. Back pressure I guess.

[sisu1970]

My problem was the opposite with needles. Plugs kept fouling with the dynojet needles switched to factory jet kit needles and the bike ran much better. Dyno jet needles had more aggresive taper. I also switched to the pingel petcock which was a good investment.

[Carter Turk]

The Dynojet's I have almost have no taper. They almost seem to taper part way down the needle then widen a hair at the bottom. I bought used with kit installed and have no idea if the needles were tinkered with.

Sounds like maybe they were or there is an older version compared to what you have. What mains are you running and needle position?

[sisu1970]

Wow! You got a few bikes. Running 142.5 mains, needle @ 4 clip from top. The carbs are 86 gsxr 1100 (34mm). 4 turns out on screws. K&N filters V&H 4into1.



82 GS 750E

[Carter Turk]

I only have two now. The 1150 Kat and my wife's 1150ES. The 90 GSXR are 36's.

[gsBert]

well, i ran without main jets and got black plugs...

guess my restriction was at the mains.

i ordered a bunch of jets: 147.5 (which i think will work) 150, 152.5 and 155.

im gonna put my needles back to the middle position out of five to see where i stand with the bigger mains will start with the 147.5...

please leave me alone with the mixture screws, it doesnt affect half throttle operation, and "nice light tan" is where i want them at that throttle opening (1 eigth), no load on the engine and less fuel consumption. im at 2 turns out and my pilots are 36.5... all good up to 1/4 throttle where i start runnign lean (needle circuit)

i'll post my results if it doesnt start snowing before i get the jets...

i'll expect to be runnign a bit lean because of the low temperature and i dont know if my slide holes are the right size, though the slides seem to nicely follow the butterfly...

[mark m]

well, i ran without main jets and got black plugs...

That's a good sign... At least you know it was the mains that were affecting the 1/2 throttle chop.

please leave me alone with the mixture screws, it doesnt affect half throttle operation, and "nice light tan" is where i want them at that throttle opening (1 eigth), no load on the engine and less fuel consumption. im at 2 turns out and my pilots are 36.5... all good up to 1/4 throttle where i start runnign lean (needle circuit)

I don't really have an issue with being a touch lean on the pilot, it doesn't hurt the motor and helps mileage, as you say. But the pilot setting certainly does affect the mixture all the way up. I was suggesting that richening up the pilot mix may help bridge the jump onto the needles because they were looking lean. Since you say the mains were the culprit, I would leave the pilot circuit alone and fatten up the mains as you are doing. Then you can tweak the pilot circuit if necessary to smooth things out after you are in the ballpark with everything else.


Mark

[gsBert]

yeah mark, you're right, lol.

when i had the needle clip in the middle groove, all was smooth, albeit too lean.
so i dont think ill have to adjust the mixture screw, especially since its only mixing fuel on closed throttle on my bike/carbs. the pilot jet is pretty big so it flows plenty. lean across the board was the mains. but if after installign the proper size mains (if i ever get them before snow falls) i find some rough spots, ill do very precise plug chops (closed, 1/16, 1/8, 1/4, 1/2) and see which circuit needs tweaking

[Hoomgar]

Bert, are you using a jet kit or stock needles?

Bert, I wont jump in as I see your getting plenty help already but I was curious about this and you didn't answer. Maybe you gave that info elsewhere and I missed it?