Shift shaft vs. Clutch Dog

[kfa4303]

Hi all. Took the boat out today and the weather was great. My '66 20 hp Johnson started on the first pull at the dock right next to a big dollar, flats skiff who looked at me a bit mockingly before I fired her up (always fun). Any who, I zoomed around at WOT to my first stop with no issues, but when i began to head home the motor started slipping out of gear. I eventually remedied the problem by holding the shift lever in FWD while underway. As long as I was holding the lever all was well and i was able to run at WOT no problemo, but if I let go it would slip out of gear. Thankfully, I was able to move around at under half speed without issue. Does that sound like more of a shift shaft adjustment issue, or a clutch dog problem? I've had bad dogs before, and this was definitely more of a "slip" than the "bang" you normally associate with worn ears on the clutch dog. I'm thinking/hoping that the vibrations from prolonged runs at WOT may have just loosened the lower shift shaft bolt/rod/coupler a bit, or something. Of course, I have family coming into town (FL) from Maine and they want to go out in the boat to enjoy the sunny, 85 degree days. If worse comes to worse, we can just go down to a local lazy river that's all no wake zones and just check out some manatees and stuff, but I'd like the boat to be tip top, if at all possible and maybe even open her up without having to sit in a funky contorted posture to do so. I'm also a bit worried that adding a passenger will increase the load and thereby compound the problem further. Are there any handy tests I can perform on the LU after I check and adjust the shift rod/coupler before we hit the water? I may not have time to make a test run out to the lake to check my work before they get here. Thanks!


P.S.
Do control cables act in a similar manner as my spare hand by holding the shift lever firmly in position? Just curious.

 

[SparkieBoat]

Re: Shift shaft vs. Clutch Dog

does that year have the electric shift or assist shift???

 

[F_R]

Re: Shift shaft vs. Clutch Dog

No such thing as an electric shift 20hp. Nevertheless, the question is sort of like which came first, the chicken or the egg. The clutch dog almost certanly is worn out. But trying to hold it in gear with the shifter, while the clutch dog is trying to kick it the other way, puts an undue strain on the shift linkage which can damage it.

So, first thing is don't engage in wishful thinking, and go in and deal with the clutch dog. While you are in there, grab hold of the shift rod and try to push/pull it up and down. Any more than minimal movement indicates wear or looseness which must be dealt with, or you will just prematurely wear out another dog.

As for adjustment, unless you or somebody else has messed with it, it probably is ok. But a check is to slowly shift forward and reverse while rotating the prop by hand. An equal amount of handle movement before it starts to enter forward or reverse is the goal. Some people try to compensate for a worn dog by adjusting the handle to favor forward. That only delays the day of reckoning when you will have to fix it. Remember what I said up front---a worn dog will damage the linkage. So don't do quickie fixes.