bayoubill

a rectifier will cause the quitting when hot problem but wouldnt affect timing. best I remember timing isn't adjustable,

check the valve adjustment

have you checked the regulator/rectifier?

hate to say it but blue smoke is oil smoke,

I buy quads and fix them for resell in my spare time, I have bought several that had clogged carbs, valves out of adjustment, etc, that would idle all day without smoking, but when I clean the carbs, or whatever and get them to really run, smoke when you get on them, some a little, some bad, the quadmaster 500 would idle fine with no smoke but when I got it running right it smoked like a tar kettle, only on acceleration though. I had to replace the rings, piston, cylinder, they were all wore out, I put new valve seals in it too and lapped the valves, but the problem was the rings and cylinder, the nickel plating was worn through in one spot and the rings had around half thickness from new. in general in a car the rings will smoke when cold and get better when hot, and vice versa for the valve seals but ive found quads don't always work that way. anymore if I get a smoker after I get it running I sell it cheap even if I lose money on it. of course if I had a quad I wanted to keep and wasn't worried about profit I would fix it.

when ones burning oil it will smoke when you get on it, or smoke worse then, its usually the rings or valve seals. it could be a bad gasket, clogged crankcase vent, but its usually rings or valve seals or both, I just sold a arctic cat with a 650 kaw v twin with just over a thousand miles that did the same thing, I sold it cheap as is because the last one I had that did that, a Suzuki quadmaster 500 with 1700 miles, cost me so much to fix,

is the smoke black or blue? black is gas and blue is oil, is it gas flooding or oil on the plug? was the cylinder in specs, even below the ring ridge line? did you hone it if it wasn't nickeled? is the crankcase vent line clear? just a few ideas

it does stick in to the carb body when seated, spray some wd on it, and seat it LIGHTLY, don't tighten it like a screw or it will strip or break the little tip off in the body, back it out 2 turns and try it, if it will idle turn it in slowly till the rpms drop, then out till they drop, set it between, I don't know what your talking about on the pilot air jet unless youre talking about the screw that holds the slide up, if that's it it just pushes the slide up to give it more gas when the throttle is at rest.

trace your hot wire from the battery to the key switch, if its hot there check that it puts power across the key switch when you turn it on, I would suspect a broken wire or bad key switch

last thing I had do that was an 04 arctic cat 90, did almost the exact same thing, it was the cdi box. have you checked the rectifier? I doubt that's it but I would check it. also it may sound stupid but smell the cdi or ecm, usually if they are bad they will smell burnt.

all they have is the stator and pick up coil under the left cover, and a rectifier/regulator, cdi box and coil, some have a resistor for an electric choke or something, I cant think of anything else, , other than that its wiring or switches. stator and pick and rectifier and coil are pretty easy to check if you have a manual. if they check good change the cdi, if its a 4 or 5 pin ac you can get one on flea bay for 5 bucks, and a 6 wire ac or dc for about 10, I just fixed a little arctic cat 90 with no fire. it was the cdi, I had an arctic cat 250 a while back that lost fire when it got hot, it was the rectifier,

I had an arctic cat 250 do that when the rectifier was bad, but the battery would go dead with the key off too,

find a wiring diagram and get rid of the remote cut off module, if it still has no fire I would suspect the cdi box.

I looked at all the videos, but its not that simple, they say a dc has 1 wire on the 2 pin side, mine has 2, and mine is bigger but not the great big one they show. there are ac and dc boxes the same size on e-bay for the gy6. anyway mine is dc, I thought it was and got a dc and it worked.

can anyone tell me if its ac or dc for sure? its a 4 stroke gy6 type engine.