TOPIC: 650 3 CYL....my arch nemesis returns.

What is it with me and these 650's? I have found and restored many many old mercs from the cloud whites thru the 80's brown stripes but have never had the challenges I always seem to have with these 3 cyl 650's. This is the third one I have had and every one began with spark issues(usually the trigger that is integrated into the dist housing) then other things challenge me.

This one had no spark which was an easy fix when I spliced in 3 new wires from the distributer/energizer. Then I got it running but it was running rough and needed the choke tapped continually to keep running. Ok...so it is a fuel delivery issue right?

I removed and cleaned the carbs thoroughly(which weren't all that bad) and that didn't help. Barely coughing and fuel running out of the carbs etc. Did what I should have done the first time I had it apart and replaced the needles/seats and floats. Adjusted the float level and drop as per specs and I also replaced the gaskets and diaphram in the fuel pump.

Pumped up the ball....no leak and got and stayed hard. Turned it over....no start. Checked spark again....still good. Pre-mix in a couple of plug holes...quick fire and burn but won't run.

I am stifled... I removed fuel line from after pump and cranked to verify fuel is pumping. Double checked the distributer to flywheel positioning and it seems fine to me. There is no belt alignment plastic pointer but I ensure flywheel has #1 cyl at TDC and that the pulley pointer on the distributor is pointing directly to center of flywheel(crankshaft).

Any thoughts before I tear it down yet again?

Thanks ,
Tim

SHOTGUN! 12 Gauge!

goto john's old merc sit. ask for fastjeff he is ace on themor call him1 610 285 4516.

I didn't have to pull out the shotgun after all. I went back and reviewed a long thread I had created last year in another forum on the last 650 issue and reminded myself of a couple of things. The initial idle screw settings after a carb rebuild on these is not the normal 1-1.25 turns out from seated but is more like 1.75 to nearly 2 turns out. So I did that and also set the distributor properly and she is running pretty good now on the hose. Changed the impeller and it is pumping and staying nice and cool.

Thanks.
Tim

Think that was your problem. Sometimes its the damn little simple things we forget!