Okay, what's white with brown specs?

I wouldn't think float height's your problem if your that close to the gasket, and the bike is level.

However, if you can't get good color on the plugs at idle, then jet needles wouldn't be the only problem either.

Just so we're clear: as I understand it, currently, you're getting white insulators at idle on all four plugs regardless of where the pilot screws are set. Is that correct?

If that's the case, that would mean it's either something wrong with all four carbs, or something they all have in common.

Things they have in common include the air box, air filter, and, to some extent, intake vacuum, due to the YICS passage.

Did you check for vacuum leaks at the throttle shaft seals? Also, what condition are the carb diaphragms in? Did you seal them with silicone grease when installing them?

One thing you could try would be to pull the air filter, or run with the carb boots off, to see if you can see the slides moving up when the throttle is quickly opened. If they're not moving, or not moving much, that might explain the mid-band leanness. Of course, running without boots or air filter will be even leaner, and would open the engine up to contamination by airborne dirt, so should only be for a quick check.

 

I made a jig for the carbs to hold them level off the bike.


I'm getting zero color......after I installed new plugs and tweaked the carbs.

...well, I haven't ran the bike since discovering that the new plugs were purely white. Just ripped the carbs apart, cleaned and put them back together.....took a short ride to test, then discovered the albino plugs.

I hadn't checked for leaks at the throttle shaft seals.
I'll put that on my to-do list tomorrow.

Ummmm......seal them with grease? No?!?

 

Chacal's got a whole writeup on carb cleaning in his parts forum. One of his tips is to use silicone grease (not petroleum grease) to hold the lip of the diaphragm in place when installing the slide. The silicone grease makes sure the lip stays put, and also helps seal the diaphragm. You can get silicone grease in the plumbing section of most any hardware store.

This grease is also good for the O-rings in the carbs, especially those on the pilot screws, that are prone to get torn up a bit.

 

I'm going to do that tomorrow. thanks again.

I just can't figure out why I'm so lean?

 

think he is talkin about the carb diaphragm when you install them to use a silicone grase to lock theboot lips into place in the groove so as to avoid a vacuum loss and introduction of MORE air to your lean problem. Just a guess

 

I hope that's the problem.

I did probe around with an unlit propane torch......with no conclusions.

 

Recently, I have encountered Air Leaks at:

Manifold Gasket between Manifold and Head.
Factory O-ring fails and allows air at higher rpm's.

Manifold to Carb.
Manifold is split because wrong Hose Clamp is used of misplaced.
Cleanly lacerates the Manifold at the Head side of the Manifold.

 

I'm going to closely examine both sets of boots....and grease the diaphragms.

The floats are set properly, and the carbs are surgically clean.

We'll see what happens tonight after work when I put them back on.

 

http://xjbikes.com/Forums/viewtopic/t=1 ... rt=60.html

After reading that thread, I realized that I'm running 110 main and 40 pilot jets.

With a 4-1 exhaust, should I be using 114 & 41(41.25?) respectively?

 

I would.
I'd much rather run rich and cook the Mill or burn a valve.

 

...an order will be placed....
new jets, petcock, and valve cover gasket......

Came home to a garage that smelled like gas.....apparently my petcock is leaky....since I had it off the bike.

 

greased the diaphragms......reinstalled the carbs.

Could not find an air leak with propane. all plugs were white. Bike ran really well......but bone white.

Must spend bike down time checking the valves, replacing petcock and jets.
I also ordered a colortune.

Thank you everyone for the help. I'll probably post again once I tweak all of these things.

 

Did you change the o-ring in the Mixture screws already?

 

Change them?
The existing ones looked pretty good? :?:

 

any progress on this?

 

I'm waiting on a set of metric feeler gauges so I can check the shim clearance accurately. I checked them with a set of standard ones....and most were around .114 and .165.....only one was way off. 0.89-ish 8O

So, I'm going to take care of that FIRST......swap the stock jets for some bigger ones (110 to 114 and 40 to 41).

I'm also going to treat my tank, replace the crispy valve cover gasket and rebuilt the petcock while the bike is "down".

At least, after all of that I can narrow down any air leaks that may be causing my bike to run so lean.

 

Do a Compression Check; first!

Don't spend hard earned money on a new saddle and tack for your horse until you know it ain't gonna up-and-die on you.

You might need the money for a new horse.

 

Won't tight valves skew my results?

I also don't follow your horse references...... :lol: 8O

 

Checking compression cold, as long as there's SOME clearance between the cam and shim, the clearance shouldn't affect your readings... if anything you'll read a tiny bit higher because you'll be getting maximum open displacement of the valve.

Now, if there were zero clearance, then your results could be way off, since the valves might actually be hanging open throughout the cycle.

 

Horse analogy explained:

Don't spend money ordering parts and having things done ... until you see the results of a Compression Test after having run the Bike so Lean.

Critically Lean Burns flash and consume every flammable source of Fuel.
The Oil Sheen on the Cylinder Wall gets used making the Cylinder Wall and Rings vulnerable to premature wear, scoring and other issues related to engine problems that can and often do become severe and costly.