1994 johnson 25 hp misses at full throttle

[mark westrick]

my 25 hp johnson misses at full throttle, it is an intermitent miss that is getting worse, the cdi power pack was replaced, carb rebuilt,new fuel pump, new plugs,still has miss, only at full throttle, compression is good. not sure if it is fuel related or electrical,thanks

 

[Bifflefan]

Re: 1994 johnson 25 hp misses at full throttle

I'm not an O/B guy.

Is it a 2 stroke?
If so, I think that you are talking about a "lean sneeze". It may be running lean at the top end. I have heard of this and saw a you-tube that had it.
I really cant help on the fix if that is what it is. But its something to think about.

If im way off then I apologize.

 

[Cofe]

Re: 1994 johnson 25 hp misses at full throttle

Is the carb "spitting" fuel when this happens? If it is, might be reed problems.

Another thought is to look at the plugs and see if one is fowling.
Have you ever decarbed this motor?

 

[mark westrick]

Re: 1994 johnson 25 hp misses at full throttle

thanks for the input, yes the motor has been decarbed, both plugs are burning nicely, also there is no spitting from carb. this miss only happens when the engine is under load, it was run in a tank and never missed once. also tried a portable tank with same result,still need help

 

[mchin]

Re: 1994 johnson 25 hp misses at full throttle

I had a similar problem on an slightly older 25 and my misses stopped when I replaced the ignition wires and soldered them to my spark plug connectors. to me and if your high speed jet is clear and it sounds like it is, I would check through your ignition. My motor also had a nice blue spark.

 

[3with1shot]

Re: 1994 johnson 25 hp misses at full throttle

Having the same issue with 94 25hp..Let me know what you find. I have rebuilt carb, cleaned fuel pump. replaced the tank and lines..