MadCapsule

I have two full sets of used carbs from Eblag on the way. I got the pair of them for 80 USD, plus shipping. Between those and some extra carb bodies my friend has, I should be able to put together a complete rack of good carburetors. Edit: Compression test shows all cylinders are over 100 psi.

I switched the 2/3 coil to 1/4 and the problem remained on the 1&4 cylinders.

I'll try that as well.

Yeah, it's quite the mystery. I'll look into some kind of fuel resistant sealant, I think JB Weld makes one. Brazing or soldering may be an option, but I'm not sure how well they would withstand the heat. Ignition timing checked out fine with an inductive timing light. Inspection of the ignition wiring didn't reveal anything that was obviously damaged or disconnected, but a second look may be in order. I suppose it could be an intermittent problem with the 1 & 4 coil or the electronic ignition (both are Dynatek pieces). If that's the case, I may just have to swear off Dynatek products and go back to stock coils and and points ignition; I've already had a Dyna coil and a Dyna ignition take a shit on me just out of warranty.

First, here's a pic of the suspected problem: All four pickup tubes are like this I've been beating my head against the wall trying to get the fueling right after installing a set of pistons and barrels from an 850 and a Vance & Hines 4-1 exhaust. All of the adjustments I've made have produced results that are inconsistent and I suspect the cracked choke pickup tubes may be letting unmetered fuel into the air/fuel mixture. Plug chops show that the 1 and 4 cylinders are fouling the plugs and they are often wet, while 2 and 3 are lean. Adjustment of the air and fuel screws has little to no effect on this. The carbs have been fully disassembled and soaked in carb dip, had all passages sprayed out with brake cleaner and reassembled with fresh o-rings. I'm currently running the stock air box with K&N air filter, fresh air box boots and fresh intake o-rings. The carburetors have 112.5 mains, pilot jets are stock and the needles are set with the clips in the center position. All parts are OEM, not from aftermarket rebuild kits. Float height is set at 25mm and the float needles all move freely. The bike will usually run fine on initial start up, but the 1 & 4 cylinders stop firing as the plugs become fouled, with occasional surging when they happen to fire. I have confirmed that 1 and 4 are receiving good spark by placing a clean spark plug in the boot for 1 or 4 and holding it against the motor while pressing the start button. So, could the split choke pickups be the cause of all this? If so, can they be removed and replaced? I can't seem to find them for sale, unless I'm using the wrong search terms. Any thoughts or advice would be greatly appreciated.

Give this a try: At a standstill and in first gear, put a small amount of upward pressure on the shift lever and rev the motor slightly over idle. Hold the revs there and try shifting into neutral. That usually works for me. You may have to play around with how high you rev the motor, so I suggest practicing in an empty parking lot.