XS360 running poorly. Pilot Jet source?

[BBS360]

So my 360 is on the road but not running well. Very poor power when first starting to roll. Died a few times taking off from red lights up slight inclines. Barely pulled across the intersection then dies.

Throttle will rev high when stopped but immediately goes down around 2k when in gear. Throttle position doesn't seem to affect it at all. Doesn't make a difference whether I open it slowly, go wide open, or anything in between.
Seems to run great when/if it gets past this dead zone.

Running stock filters but custom exhaust. Pipes aren't straight through. Final orifice size is close to stock.

I've been dealing with the right cylinder not firing consistently but it seems to be going now. Good spark on both sides but plugs seem to indicate both sides running rich and right side oily.

Ignition coils tested well last year but will retest this week to be sure.

Left: Right:

Timing had been set previously but rechecked timing yesterday to find the right side was firing way early. Figured that might be the problem.
Reset it and the gaps.
No noticeable improvement.

Compression isn't great. Need to get a tester to redo it again but I seem to recall getting around 120psi when I last borrowed a tester. Maybe slightly lower on the right side.

Carbs have been pretty thoroughly cleaned more than a few times. Diaphragms are old but no signs of damage.

Still experimenting with pilot screws on the carbs. Barely seems to make a difference turning them in or out any amount.

One odd thing is that one pilot jet has a slightly larger orifice than the other. No way to measure it but a wire that fits through one easily won't fit through the other. Both marked 17.5. Clean.
Dunno if a previous owner did something to them but it sure seems like having matched jets on both sides would help.

There is one listing for 17.5 pilot jets on ebay but at CA$30 each I wanted to see if anyone might have another source.
Haven't found any other sizes of pilot jet. Hard to even find the part #s to search with. Don't see any #20s available.
There is also a Keyster kit for the 750 that shares the same pilot jet but I don't think anything else in the kit matches up.

Any and all suggestions are welcome.
Might try switching pilot jets between carbs to see what happens.

 

[xschris]

I would check to make sure the idle mix screws have not broken off in the carbs. Also the last guy that owned it may have had this happen and drilled the one side out and now the hole is way to big making it run very rich. A non-stock exhaust will also cause issue.

 

[BBS360]

Thanks xchris. I didn't think that was as much of an issue on the 360's carbs?
Pulled the screws and I'm pretty sure they're ok. Both measure exactly the same length.

I can swap out the final orifice plate in the mufflers for other sizes. I'm guessing a more free-flowing exhaust would lean out the mixture some?

Any thoughts on other sources for the pilot jets?

 

[xschris]

I would also check the holes the screws went in and see if they look the same. Not sure other than yamaha to find oem stock pilot jets. So few bikes used this style.

 

[BBS360]

I'll try the dealer for the jets.

Temporarily swapped ignition coils to absolutely no affect. Bike starts as easily with only the left coil hooked up as with both coils firing.

Carbs are apart again. Rechecking everything. Screw hole looks clean and uniform. Carb cleaner shoots out all the right holes.
Swapped pilot jets left to right to see what happens. Might try tweaking the float height to lean things out slightly before putting the carbs back on.
Will buy new plugs to get fresh readings.

Next will be a compression test. Then checking valve clearances. Pretty sure they were good but at this point I'll try anything.

 

[BBS360]

Swapped the pilot jets, set the floats up to 28mm and she's much happier.

Both cylinders firing. Pulls better from flat stops... dies on hill starts.

Need to check chain tension. I suspect it may be loose.

Will get new plugs for a better reading.