"65" Johnson RKL 24 L Full Throttle Problem

[Beeched]

On my 65 RKL 2Johnson, I put in new points and condensors that seemed like it took care of a miss that I had. I took the boat out to the lake today and had a different problem. When throttle was advanced to full it seemed like I was getting about 1/2 throttle. Brought boat back from lake and set motor in test tank. Took cover off, started right up. advanced to full throttle and motor reved up to where I think it should have been, do not have a tach. Did I seem like a fool or what. Did some other minor things to the steering, put cover back on, started just to check. Started right up, advanced throttle up to full throttle, reved up then RPM backed down to about 1/2. Removed cover, reved up to full and stayed. Put cover back on and the motor went back to about 1/2 RPM. Opened trap door where the pull rope and carburator access is and the RPM went back up. The cover seems to be a sealed unit, there is a possible path for air where the transom mount attaches to the motor. It is not blocked by anything that I can see.

Any thoughts from the more seasoned people here?

 

[tashasdaddy]

Re: "65" Johnson RKL 24 L Full Throttle Problem

sound like it is sucking exhaust. the don't like dirty air. probably the seal between leg and powerhead. also please put the hp in with the model, we have to look it up, can't keep all the model #s in our head.

 

[Beeched]

Re: "65" Johnson RKL 24 L Full Throttle Problem

You're right, I didn't put in the HP, anyway it is a 40 HP. I did replace the filter in what they are calling the silencer. About a 3" cap on the bottom of the bottom shell. It was completely soaked with fuel and oil. It might have helped a little bit, not sure though. I cannot detect any leakage of exhaust from the lower unit at this time. Will continue looking for things.

Thanks

 

[F_R]

Re: "65" Johnson RKL 24 L Full Throttle Problem

Tell ya a little secret. Not really a secret, but a bit of knowhow. There is an o-ring on top of the water pump housing. And two more on the spacer tube if it is a long shaft. If any of those o-rings or the spacer tube are left out when changing a water pump, exhaust smoke will go up into the hood and smother the motor.

Note this though: They won't run in a tank with the hood on. They can't deal with that much smoke.

Also, dropping back and forth between full and half speed sounds more like it is sometimes running on one cylinder (half speed).

 

[Beeched]

Re: "65" Johnson RKL 24 L Full Throttle Problem

I set up a fan to keep the smoke clear from the motor, that helped. It would still rev up and die down without touching the throttle. I open the access door about an inch and it stays reved up. I might try it on the lake next weekend and see what happens. I read with interest another post on here that mentioned the coils arcing to the motor block. I do have 2 new coils coming in to replace the old ones. I discovered that the old coils had a goodly amount of silicone sealant smeared all over. That would tend to make one believe that in years past there was a spark problem.

Once I get all of these things taken care of I might have a rebuilt motor : ).

Again,,,,,,,I thank all who have helped me on here.

"Keep on Fishin!!!"