1988 Johnson GT150

[mnewcomer1]

I have a Johnson GT150 (1988). I had carb rebuilt, new plugs also. It ran fine however, it would bog down at full throttle. It almost seamed like it had a second gear. Sometimes it would run 58mph, but mostly 48. Someone said to change plugs because sounded like one was fouling out. I check plug wire and they seem ok. I just started it and checked fire to each plug. All had fire except one. But when I pulled each wire loose when running. the engine didnt really change in sound but only for one and it almost died. Is this a coil problem??? Help please.

 

[emdsapmgr]

Re: 1988 Johnson GT150

All the coils on that engine are the same. You can swap two of them for testing purposes. If the bad coil is moved to another cyl and the problem (no fire) moves with that coil-then replace it. If the problem stays on that same cyl, then you have another ignition issue. Weak ignition components tend to fail when the engine heats up to normal operating temps. (may run fine when cold, but not when warmed up.)

 

[SparkieBoat]

Re: 1988 Johnson GT150

follow instructions in my sig below.