Optical timing sesor

I have a 1992 J150 GLENC motor starts runs for awhiles than dies. Let it sit it will start up for awhile and than dies again. Or sometimes will run all day. Never sure what is actually going to do. Rebuilt all carbs replaced all fuel lines cleaned fuel tanks unhooked oil side of vro mixed fuel. Not sure if pump is breaking down. Have 5-6 lbs of pressure cold not sure warm never tested. Could optical timing sensor be breaking down? Or could this be another issue? Parts are to expensive to guess at.
Any help would be greatly appreciated.
Thanks,
Lonnie

Double posted some how.

If it starts & runs.............Then slows down like it is running out out of gasoline ? NOT a sudden, instant shut down, like ignition ?

Borrow a GOOD CLEAN gas tank with some gas / oil in it & hose clamps to temporarly tie it into your engine to hand pump it for a positive pressure flow by your constant hand squeezing...............Cheapest way I know of to prove engine is basically O K.

As a part starts to fail many people / mechanics keep readjusting idle speed & mixture until it is hopeless. Then the problem gets attention.

That is how I handled my idle problem with a stretched out fuel pump old diaphram. Ran just like you do.

Mine is a 1995

You will need to know if you are losing Ignition or fuel. Run the engine until it dies and check for spark. FYI, running and then dying sounds like a power pack failure. CDI sells kits complete for the OIS engines. You get the Eye, the Power Pack, the stator and the timer base. The price is good when you purchase them as a set. I would change all as a set.

thanks for the info i'll try the engine does slow before it dies sometimes but starts and runs again after about 5min if it turns out not to be fuel issue where can i find the ignition kit mentioned in the other replies thanks again lonnie

With ONLY a cold engine.

Pull each spark plug. Does either one look coated with black stuff ? It good looking. Reuse them. Post back on their conditions.

Also notice if they look almost white or white with pimples or blisters on them.