Mixture screw has no effect on RPM (pilot too big?)

[moparerrnocar]

If the mixture is fully seated and the bike still idles no differentially does this mean the pilot is too large?

My bike has no change in rpm in relation to the mixture screw (anywhere from seated, to 4 turns out). Idles set @ 900-1000. Currently it has 45 pilot but I think its too big.

Bike is a '94 883/1250, 883 heads w/ 1200 valves (10.3:1), SE AC, 1.75 drag pipes, SE .497 cams, dyna 2000 ignition and twin fire coil. The carb has a red yost needle in the #4 clip (w/o shim), yost tube, yost spring, and 180 main.

[sportsterdoc]

Originally Posted by moparerrnocar

If the mixture is fully seated and the bike still idles no differentially does this mean the pilot is too large?

My bike has no change in rpm in relation to the mixture screw (anywhere from seated, to 4 turns out). Idles set @ 900-1000. Currently it has 45 pilot but I think its too big.

Bike is a '94 883/1250, 883 heads w/ 1200 valves (10.3:1), SE AC, 1.75 drag pipes, SE .497 cams, dyna 2000 ignition and twin fire coil. The carb has a red yost needle in the #4 clip (w/o shim), yost tube, yost spring, and 180 main.

I doubt that your pilot is too big.
My first thought is a vacuum leak.
How does it run?

[Deimus]

I remember from some thread years ago where someone was having trouble trying to cure a too rich situation. It turned out that the diaphram in the petcock had a small leak and fuel was getting into the engine via the petcock vacuum line. I'm not suggesting you have this issue. I'm only making you aware of a possible source of fuel if you still run a petcock with a vacuum line.

[moparerrnocar]

Originally Posted by sportsterdoc

I doubt that your pilot is too big.
My first thought is a vacuum leak.
How does it run?

I've sprayed carb cleaner around the boot and manifold b4 but noticed no change. How would a vac leak allow the bike to idle w the mixture screw seated?

It runs, "ok", throttle blips and roll ons could be better. Its not as responsive as I think it should be. It also pings when passing on interstate if I dont down shift. You only hear it if you turn your head and put you ear near the tank, otherwise there's too much wind/exh noise. I dont have a tach but you grab a fist full of throttle @ 2,500 in first gear it rips your arms off and pulls the wheel of the ground about 2" when I grab 2nd. Runs great and pulls strong all the way to 6k. I've backed the timing off trying to get rid of the ping, but if I go any further I'll sacrifice torque. This was off topic, but I figured I should mention it.

[rocketmangb]

Might check the float level

[Gcram399]

Your engine set-up is similar enough to what I have on my 97. Tuner used a Dyno-Jet Carb Kit. Clip is on the 3rd knotch, 45 pilot, 180 main and 3.5 turns out on the idle mixture.

Your 45 pilot should be fine. I'd look for fuel getting into the mix from somewhere else.

[sportsterdoc]

Originally Posted by Deimus

I remember from some thread years ago where someone was having trouble trying to cure a too rich situation. It turned out that the diaphram in the petcock had a small leak and fuel was getting into the engine via the petcock vacuum line. I'm not suggesting you have this issue. I'm only making you aware of a possible source of fuel if you still run a petcock with a vacuum line.

The petcock diaphragm is a possibility, as well as the enrichener circuit.

[sportsterdoc]

Originally Posted by moparerrnocar

...I've backed the timing off trying to get rid of the ping...

Have you checked your VOES?

[oldboy]

I had the same with my '06 1200. Finally read a post by another member (don't remember who) who changed out their accelerator pump diaphram and that took care of the issue.

I changed mine, the old one didn't have any tears or holes. It was discolored and had some corrosion on the top side. After changing it, my mixture adjustment finally works.

Don't know if your bike, being older, has an accelerator pump, just my .02.

[moparerrnocar]

Originally Posted by sportsterdoc

The petcock diaphragm is a possibility, as well as the enrichener circuit.

Have you checked your VOES?

No diaphragm, but enrichener might be a possibility. My voes works, but not sure where it should be set.

Originally Posted by oldboy

I had the same with my '06 1200. Finally read a post by another member (don't remember who) who changed out their accelerator pump diaphram and that took care of the issue.

I changed mine, the old one didn't have any tears or holes. It was discolored and had some corrosion on the top side. After changing it, my mixture adjustment finally works.

Don't know if your bike, being older, has an accelerator pump, just my .02.

Really, hmm, you know that just might be it. I too checked it for cracks/holes and found nothing. I guess its worth a try, sure cant hurt. Thanks