1989 johnson 150 vro gt

[fishgulper]

had no power to one bank. replaced powerpack and put coil wires on as per instructions and motor backfires like a son of a gun
please help this boat has been down way to long, time to hit water i hope

 

[emdsapmgr]

Re: 1989 johnson 150 vro gt

It will backfire like that if you have the power pack wires going to the wrong coils. They are color coded and it is easy to cross the wires. The orange power pack wires should be as follows: the orange wire with the blue tracer feeds the top coils. The solid orange wire feeds the middle coils. The orange wire with the green tracer feeds the bottom coils. Just double check that the spark plug wire from each coil goes to that same spark plug.

 

[fishgulper]

Re: 1989 johnson 150 vro gt

thanks for the info, now have backfiring prob fixed. put the boat in lake but still is bogging down and only get 3200 rpm's. could this be fuel issue, had stabilizer in fuel over winter and just before changing powerpack cleaned carbs and changed fuel filters. powerpack has 5800 rpm limiter

 

[emdsapmgr]

Re: 1989 johnson 150 vro gt

Double check your spark at 3200 with an inductive timing light next time you go out. If all 6 plugwires look to be firing ok sparkwise, then look for a fuel issue. When it bogs at 3200, have a friend constantly prime the fuel hose bulb. This will force extra fuel around the pump, directly into the carb bowls. If it runs top end ok at that point, you may need a new fuel pump.

 

[fishgulper]

Re: 1989 johnson 150 vro gt

thanks for the info , i'll try that

 

[fishgulper]

Re: 1989 johnson 150 vro gt

had friend pump fuel ball to force fuel in carbs but still no difference. also when trimming motor it seems to miss really bad to the point where it chugs. is it possible it needs to be retimed after new powerpack went on. seems like timeing to far advanced. please help

 

[emdsapmgr]

Re: 1989 johnson 150 vro gt

Try using an inductive timing light to check spark when the engine is not running right. Would be good to know if the spark is breaking down and on which cylinders. Unlikely that installing a new power pack had made any significant change to the engine timing that would cause your current problem. Also possible you have a carb issue. You said you overhauled the carbs-did you remove all the jets and inspect them? Did you use an aerosol carb cleaner on each passageway in the upper carb body?

 

[fishgulper]

Re: 1989 johnson 150 vro gt

yes sprayed a parts cleaner through the jets(aerosol can). this motor was rebuilt by my brother and i and just isn't quite right. everything new from honing cylinders to new pistons and rings,powerpack,stator,flywheel. earlier i had no spark on starboard side. changed power pack, now have spark to both sides. also it backfires through prop. the boat ran ok with a little miss after rebuild, then was taken to marine shop to be timed and has never been the same since