White plugs affect performance?

[mschor]

Do plugs foul out when they turn white from a lean condition? Mine are white and I'm trying to time it, wondering if I need to clean/replace or will they take care of themselves once I get the mixture right. Seems to run worse the longer I run it

[mschor]

TUNE it, not time it

[3Phase]

Do plugs foul out when they turn white from a lean condition? Mine are white and I'm trying to time it, wondering if I need to clean/replace or will they take care of themselves once I get the mixture right. Seems to run worse the longer I run it

No... some of the new gasoline mixtures burn pretty clean and don't darken plugs like real gasoline used to do. It can be hard to tell just by looking if it's a new plug; a clean and mean white plug that's working fine, or lean and mean, melting machine white plug.

Were the plugs dark before and they've turned white from running lean while you've been working on the bike or are you waiting for them to get dark?

[Radioguylogs]

I agree that white plugs do not need to be cleaned- they are already clean.

My SF plugs run tan.

My SG plugs run bone white.

Both bikes have the idle mixture set by counting turns according to this forum's recommendation. The SF idles rich, the SG seems spot on.

I think my plug color is more a function of the jets than the idle mixture.

[mschor]

Thanks both for your experience. These plugs were new, no black. My old plugs went black and fouled out due to previous k&l pilots.
Mike, you preset the mixture screws and didn't adjust them individually? I set mine at 2 turns out and tried adjusting them, but I can't hear any change in idle except when they're fully closed.
It's still a little slow in throttle response, and comes back down slowly as well. Doesn't cough or complain much, just slow in going up and down. Not sure what that indicates. Going to sync it again tomorrow.
Bowl fuel levels are pretty much spot on, but definitely not the same float levels....I had to vary the float levels up to 2-3mm to get the running fuel levels even. All I can think is that the k&l float needles have inconsistent springs.

[motoman]

Thanks both for your experience. These plugs were new, no black. My old plugs went black and fouled out due to previous k&l pilots.
Mike, you preset the mixture screws and didn't adjust them individually? I set mine at 2 turns out and tried adjusting them, but I can't hear any change in idle except when they're fully closed.
It's still a little slow in throttle response, and comes back down slowly as well. Doesn't cough or complain much, just slow in going up and down. Not sure what that indicates. Going to sync it again tomorrow.
Bowl fuel levels are pretty much spot on, but definitely not the same float levels....I had to vary the float levels up to 2-3mm to get the running fuel levels even. All I can think is that the k&l float needles have inconsistent springs.

Last statement, very correct.

[TopCatGr58]

The throttle and rpms should drop almost immediately when you close the throttle, so hanging idle is a sign of carbs out of synch, but also possibly too high an idle setting, at least for trying to tune by ear. You want to have the idle fairly LOW so when you turn them out/richen them up, you can THEN hear the rpms increase a bit.

Too high an idle can also cause the vacuum advance to engage some which could also cause a lag on the throttle drop after release.

T.C.

[Radioguylogs]

Deja vu

Mike, you preset the mixture screws and didn't adjust them individually? I set mine at 2 turns out and tried adjusting them, but I can't hear any change in idle except when they're fully closed.
It's still a little slow in throttle response, and comes back down slowly as well. Doesn't cough or complain much, just slow in going up and down. Not sure what that indicates. Going to sync it again tomorrow.
Bowl fuel levels are pretty much spot on, but definitely not the same float levels....I had to vary the float levels up to 2-3mm to get the running fuel levels even. All I can think is that the k&l float needles have inconsistent springs.

mschor:

I dug up this from my previous experience on my "Bagger" project:

"However, despite by best efforts, I can't find any change in vacuum when I adjust the idle mixture, and I don't get a drop in RPM until they are closed. I can't seem to learn how to set the idle mix , so for now I am relegated to counting turns. Two turns was too rich. It would not go back down to idle properly. One and 1/2 turns works well."

I also had this experience with K&L float needles:

"First thing I discovered was that one of my needles has a severely bent wire on it....this would pre-compress the spring by forcing the float tab into the body against the spring....



After I straightened the wire, the K&L and the Mikuni have same overall dimensions, although the 'slot' under the K&L wire is fatter and takes up more of the body (with no consequence):



Finally, I compered the overall K&L needle in the K&L valve seat with the same Mikuni parts and didn't find any problem:


_____________________________________


I found that after I straightened the wired on the K&L needles, I am satisfied using the K&L needles in my bikes.

I also had the super rich fouled plugs from oversized K&L pilot jets- we have been on the exact same path.

You are getting close

[motoman]

Mike, if those K&L hanger wires give you another issue, you'll find that using the one continuous wire on the original Mikuni float needles works way better, and have no issues. Lest was what I swapped on the K&L needles when I saw the open ended wire hangers on them before installation. Overall length of the K&L float needles IS a bit shorter than the Mikuni float needles, and CAN cause what happened to the K&L float hangers in your case.

[3Phase]

The "problem" with K&L or other float needle sets is consistency. The assemblies may work just fine but if they're not all the same installed height as the OEM Mikuni sets -- and with each other -- then the stock float height settings will be wrong.

If the needle valve body diameters are off then the valve body o-rings may not seal correctly in the later '80-'82 style carburetors and the fuel will leak out around the new needle valves.

You can use the OEM float heights as a guestimate that will let the engine start and run, then use the running/dynamic test to get all of the fuel levels equal across all four carburetors. As long as the needles open, close, and seal, then it doesn't really matter whose needles and seats you use or if they were machined by monkeys with too much coffee.

When you sell the bike, make sure you don't tell anyone what you did.

[mschor]

Encouragement and helpful info, much needed and appreciated! Back at it early tomorrow

[skids]

(snip)
You can use the OEM float heights as a guestimate that will let the engine start and run, then use the running/dynamic test to get all of the fuel levels equal across all four carburetors. As long as the needles open, close, and seal, then it doesn't really matter whose needles and seats you use or if they were machined by monkeys with too much coffee.(snip):

And you don't want to have to bend the float tang very much to compensate.

[mschor]

And you don't want to have to bend the float tang very much to compensate.

Well I ended up bending the tangs upward on some and downward on others, but nothing's sticking and levels are good in the clear tube check...even letting it warm up made a sizeable difference in the fuel levels, probably 3 mm in a a couple of them from starting to warm.