1989 Johnson V4 90HP

[Don Tauer]

Problem, when starting this engine, and about 3 min after going to full throttle,to get up on plane the engine seems to drop the 2 port cyls. Apology why I say, for these are the 2 spark plugs that have tan colored beads around the center porcelain, and at the electrode itself. The starboard plugs normal condition.
Bring the throttle back to 3000 RPM and it seems to run ok. This power head has about 20 hrs since being overhauled. Prior to this happening which started about one week ago, everything was fine and operated like a new machine. Have not replaced the plugs yet, but will do when I get some feed back. Running Mercury quicksilver oil,removed the VOR and use direct mix 50/1 since rebuilding.

 

[emdsapmgr]

Re: 1989 Johnson V4 90HP

Is the port side overheating?

 

[Don Tauer]

Re: 1989 Johnson V4 90HP

No there is no evidence of overheating. I will run it this afternoon when I get it on the river, and feel with my hand if there is a temp. differential.What really concerns me is the ash semi hard deposits on the plugs on the port side. I have also been reading about the grounding of the coils with the yellow and black wire. Will remove them also to see if there is a difference.
Don

 

[Molaker]

Re: 1989 Johnson V4 90HP

That appears to be a fuel starving problem on the port side rather than a spark problem. I'd suspect a dirty carb as the more likely culprit.

 

[cougar1985]

Re: 1989 Johnson V4 90HP

That appears to be a fuel starving problem on the port side rather than a spark problem. I'd suspect a dirty carb as the more likely culprit.

have to agree.had the exact same problem with my motor and exact same symtoms(2plugs almost white),in my case it was the primer bulb was defective and the motor was starving for fuel.new bulb ,no problem now.so a dirty or plugged carb is not out of the question if its not the bulb.

 

[Don Tauer]

Re: 1989 Johnson V4 90HP

Good afternoon, well hopefully I have resolved my problem. Replaced the 4 plugs, installed a new primer bulb, and made a direct connection from the carbs to the primer bulb(eleminating the quick connection). Also I did get a message that the tan beads may have been moisture in the fuel, and that was the residue. I put in a can of heet into a full tank of fuel. took the unit for a ten mile ride on the river and things seem to have straightened out. May be until tomorrow :LOL. Wish to thank all who lent information as to the solution for my problem.
Thanks
Don