1990 Johnson 150 gt problems

[TimmyC]

This is whats go going on, The motor will run good to the place you want to fish. Then it might run good to the next place you want to fish. Then it will bog down and will not get past 2000 rpm. and misses really bad.

This is what I have done to the engine. Compression tested at 100 psi on all 6, took the carbs off and cleaned ( they have been rebuilt last year) changed spark plugs ( they looked oily and a little wet) looked for loose connections on the coils they looked good. Changed fuel to make sure ratio was 50:1, checked to see if all cyl. where fireing, they all where good. ( what kind of test can you do to see if they are firing hot enough?)

These are what my guesses are that maybe wrong, vor pump, coils, power pack, stator, and maybe some other fuel related problems. Please give me some help this is killing my fishing.

Thanks guys

 

[emdsapmgr]

Re: 1990 Johnson 150 gt problems

You might be having ignition problems. These tend to show up when the engine gets to operating temps and the electronics heat up. Take an inductive timing light with you and check the spark on all 6 plug wires next time the problem shows up.

 

[TimmyC]

Re: 1990 Johnson 150 gt problems

how do you read these, I have never used one?

 

[jtcarter]

Re: 1990 Johnson 150 gt problems

If you're idling excessively or even a lot of the time, your plugs will tend to look a little wet. Are they a tan color when you wipe them dry or black and oily looking? Get a spark gap tester or make one. I myself just pull them one at a time and get zapped. When you get the plug wire within 1/2 or 7/16 it should jump the gap between it and the plug. You should notice the engine increasing rpm, telling you that plug is firing and go to the next one. Pull them all one by one and make sure you can tell the engine changing tunes on each one.
After that i'd check my fuel filter for trash. Make sure all your hoses are tight from the tank to motor. Inspect everything under the hood. Run it on muffs and look for fuel leaks. It could be a clogged jet in one of your carbs, might be time to go through them again if you haven't already.

I'd start there and see if you can't figure it out.

 

[TimmyC]

Re: 1990 Johnson 150 gt problems

When i wiped my plugs off they are a tan color, I cleaned the carbs today before I went fishing and it did the same thing. They are just a little oily but not real bad. I am going to look for loose fuel hoses, and check the carb linkage, I read that if they are letting the flaps go past horizontal that they will cause flooding at high speed. They all are firing when I put the engine on the muffs and run.

Does anyone think that it might be the vor2 pump? Someone told me that it was it but I thought that i would only do that at high speed or would do it all the time.

 

[jtcarter]

Re: 1990 Johnson 150 gt problems

Go through your fuel system with a fine tooth comb. Did you run a thin piece of wire through those jets or just spray? If you exhaust all possibility's with the fuel, if you can make sense of how to test your powerpack i'd start there next. Another thing you can try is starting your motor at night, removing the hood and watch for spark jump around your plug wires and coils.

 

[TimmyC]

Re: 1990 Johnson 150 gt problems

changing power pack tomorrow I hope that is the prob, if not I am going to go to the stator.