OBJ
Supreme Mariner
- Joined
- Dec 27, 2002
- Messages
- 10,161
Original symptoms.....<br /><br />Got throttle with throttle plate open but no idle.<br /><br />Compression little on the low side at 60/55 psi but runs strong.<br /><br />Points and condensers replaced...coils good...good spark.<br /><br />Put new spark plugs in (J4C at .030+)<br /><br />Threw in tank and hooked up my shop tank. Started Ok. Let it rev till warm and when I came back off throttle plates it coughed and quit. Ran needle in and backed out 3/4 turn. Same results. Adjusted needed more in and out with same results.<br /><br />Checked all the fuel lines. Cut the ends and reseated with new ties straps. Cleaned out fuel pump filter and put new filter screen in. Checked pump by blowing into the inlet and then sucking out. Pump seems OK. Later put a psi gauge on the outlet and it pumped 3psi.<br /><br />Still no change in engine. Pulled carb and disassembled. Soaked in carb cleaner and followed up with spray carb cleaner into all ports and followed that up with compressed air. The only place I couldn't get to was behind the filler plug over the calibrated port. Plug would not come out and I didn't want to force it. So I did the best I could to clean it out. Checked the reeds with carb off and could see no apparent physcial damage and all were shut.<br /><br />Tried the engine again. Same thing but just a tad (not much) better. Can't see anyplace on the engine that would be sucking air. Seal on top appears tight. Even rechecked the point gap.<br /><br />Idle it down to where the throttle plate is getting closed and it starts coughing and eventually quits. Pumping the primer bulb has no effect.<br /><br />Please....someone help save a wrench's sanity. I won't let this thing beat me.<br /><br />Jim
You already tried stuff I would suggest.<br /><br />Since it dies, that suggests that whatever the culprit is is common to both cylinders and is related to getting fuel/air when the throttle plate closes.<br /><br />Have you tried going at the idle orifice in the carb throat just behind the butterfly? A fine wire bent into an "L", coming in from the reeds end of the throat can get into it. There might be something there that the cleaner and air didn't clear.<br /><br />Good luck, and let us know if that works.