Troubled in Cincy (merc model 70)

my compression was 130,130,130 with a warm engine. Still not sure but it's looking like way off timing. I will let you know. Thanks.

 

Possible solution found

I believe we had two issues with this motor. One was a fuel issue or I should say lack of . One float was bad and both were out of adjustment. Once we got fuel flow it still would'nt start very easy and still would not run in the water. More checking was done and we found the # 2 coil corroded real bad and the spark plug wire looks bad also. We tried to clean them up and it started right up and idled great but after about 10 mins. started backfiring alittle and died out. So we are getting new coils and wires and will keep everyone advised of the results. Thanks for everyones help so far.

 

I mention this often and sometimes get yelled at for it, but you're best bet with an old engine is to start with a level playing field, by replacing all the consumables, a comprehensive tune up, full up testing and rebuilding of the bolt on stuff, R&R all hoses, belts, etc. This way you know what you have, when it was serviced and what also will likely need service soon.

 

Update to Troubled in Cincy

We have good compression. 130,130,130. It has a new trigger,plugs,wires,fuel. Coils have been tested by a mechanic and are firing good. We have rechecked the lower carb and cleaned it by soaking and carb cleaner and everything else we could find. The center venturi have alot of fuel coming thru them. I don't think it's a fuel issue any more. But the lower carb has no affect on the running on muffs or anything else at this point. I have had it running and can remove the idle screw and tighten it up and nothing happens. The fuel is being sucked into the top carb and into the motor but the bottom carb produces the fuel but there is no (none) being pulled into the motor. Bad reeds ??? Would that be the next step here???? aLSO FUEL PUMP WAS ALSO REBUILT.

 

Soaking a carb doesn't clean them. You have to disassemble them, clean all the passages, all the orifices, check clearances, etc. An unresponsive carb is a classic indication, it's gummed and plugged up with gunk and varnish.

 

when its running put your hand over the carb to choke it
See what the different is when you do it to each of the 3