Re: 1985 60 hp johnson motor(PLEASE HELP)
When I say "Go Flat", I mean that the primer bulb originally has its normal shape at first, then as the engine runs, the bulb actually starts to compress by itself. If this is what happens, you have a fuel restriction between the bulb and the fuel supply. If, on the other hand, the bulb is retaining its original shape and is just simply not full of fuel, that is a normal condition.
The fuel primer bulb should get quite hard when priming. If the carburetors are not flooding (which should be obvious), check to make sure that the VRO pressure line is not feeding fuel to the crankcase. If these two areas are okay, it might be good to purchase a new primer bulb to avoid further problems.
If the change in rpms is sort of gradual, that would indicate a fuel problem. If the rpm change is instantaneous like turning a switch on or off, that would be ignition. Which scenario is taking place?
Spark plugs should be Champion QL77JC4 plugs, gapped at either .030 or .040 . One gap or the other may provide improved performance. Are you using these plugs, and what do your plugs look like (brown, black, fouled with metal, dry, wet)?
Compression should be 100+ psi and even on all cylinders. What are your readings?
Spark, with plugs removed, should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Does it? Note that using spark plugs to test the spark is a waste of time, the 7/16" gap is important.
Let us know what you find.