1981 Johnson 115 Hp Not reaching RPMs

[RickN]

My 115 Hp just started this. It use to idle around 1000 rpms. Now it idles around 700 rpms then dies. When running it at full throttle, it use to top out at 5500 rpms (30 knots) now it runs around 4500 rpms (22 knots). The fuel line has two filters, an inline (just changed it) no difference and then a fuel/water Racon filter (I also drained the water out which made no difference). The fuel pump is new on the motor and Changed the fuel lines. I am also ordering a new Racon filter cartridge. Any suggestions on what to trouble shoot? Thanks

 

[buddyholly]

Re: 1981 Johnson 115 Hp Not reaching RPMs

does it still idle smooth only at a lower rpm? it could be your low speed jets could be getting plugged. mine did that too but it idled rough .

 

[willamettejeff]

Re: 1981 Johnson 115 Hp Not reaching RPMs

It's time to do compression and spark tests. You may have a cylinder out.

 

[Cricket Too]

Re: 1981 Johnson 115 Hp Not reaching RPMs

Sounds like your definitely down a cylinder. I agree with williamettejeff, check spark and compression on all 4.

 

[RickN]

Re: 1981 Johnson 115 Hp Not reaching RPMs

Thanks for the input, I will check do the checks and hope it is my jets...