1988 Marathon No Fuel

[NJguy]

So I just completed a full engine rebuild both upper and lower. Went to run it and it ran rough for about 30 seconds and stopped, it idles smooth, has spark, 140 compression, I did notice the old fuel pump leaking so swapped that out but now is still not getting fuel. Also did the old starter fluid test to check all the seals and no change in idle speed. I could use some help. I have read on hear about a reed valve maybe be clogged but do not know where to look for that. Any help would be appreciated.

[cart around]

I see three red flags here. Full rebuild, 140 psi compression, and idles smooth.

140 psi is way too good for that engine. 120 is about the best you should see.

Ran rough for 30 seconds then quit.

Idles smooth... These engines don't idle. You are most likely just turning on the starter.

My suggestion is to remove the exhaust pipe, move the piston up, and down, and watch for a square hole in the side of the piston.
If you see that square hole, you get to yank the engine, and turn it around. The hole is supposed to face the intake side.

[NJguy]

By idle I do mean just turns over with the starter not actuality running, just worded it badly. The compression is actually 115, my gauge is shot apparently. I tested it with a friends after reading your post and will double check the cylinder tomorrow. Still not sure why I'm not pumping fuel.