johnson 20hp jumping out of forward

[will71]

Hi all,
I have a 20hp johnson seahorse that has developed a problem of jumping out of forward gear and reving out. I dont have a manual for this and am pretty new to outboard engine ins and outs. Anybody have any suggestions of what the problem might be.
the model no is 20R71R
an image of the plate is attached.
thanks

 

[jasper60103]

Re: johnson 20hp jumping out of forward

It sounds like a worn clutch dog. Does it feel like you hit a log? You can search for "clutch dog" on this forum and will find a lot of info on this topic. Your options are to take apart the gearcase and replace the worn parts or buy another lower unit. Ebay is a good source for a manual and parts.

 

[F_R]

Re: johnson 20hp jumping out of forward

It sounds like a worn clutch dog. Does it feel like you hit a log? You can search for "clutch dog" on this forum and will find a lot of info on this topic. Your options are to take apart the gearcase and replace the worn parts or buy another lower unit. Ebay is a good source for a manual and parts.

"Feels like it hit a log" is a classic description. It jumps out of gear, rotates 180 degrees and slams back into gear with a jolt. However, the 1971 has the detents in the clutch dog, and sometimes when it jumps out it stays out, which seems to be what you are describing. You actually have to put it back into gear with the shifter lever right? That would distinguish it from another problem, a spun prop hub.

The cure is a new clutch dog. But don't be misled by wishful thinking. 90% of the time the forward gear is worn also, and just replacing the dog is a waste of money because it will soon fail if mated to a worn gear.

Here is an example of a severely worn dog. They will jump long before getting anywhere near this bad.

 

[will71]

Re: johnson 20hp jumping out of forward

Hi thanks for the info, So do you think that the parts are still available for this engine. Will it cost a lot??. One other suggestion I had heard of was flicking the dog around. would this work?

 

[jethro66]

Re: johnson 20hp jumping out of forward

Yes u can but only temp.