25 horse '72 Johnson slipping out of gear

Hey guys - new to the forum and I have a question.

I have a 1972 25 horse Johnson that has been running like a top lately. I had a problem this past time out. I was running along at full tilt and the motor just slipped into neutral (gear selector is on the side). The motor tried to shift itself back into forward (and kept getting kicked back into neutral) but made the outboard shake as it rapidly went back and forth between the gears. If I would back down, I could shift it back to forward and continue along at a slow speed. I eventually limped back to the launch by going slow and holding the gear selector into forward. After a certain amount of time (even at slow speeds) the gear selector would pull back into neutral (even though I was holding against it).

I'm limited with motor knowledge, but to troubleshoot I opened the small slot (not sure of the name, but held up with two flathead screws) to see where the rods met inside the shaft. They were tight and I wasn't able to force it down to make the connection between that rod and the gear below it any tighter (sorry for the lack of technical talk). If anyone can help me without me having to drop the lower end and replace that gear, I'd love to hear some suggestions.

Thanks!

Re: 25 horse '72 Johnson slipping out of gear

Welcome to iboats.

It could be something different, but unfortunately, it does sound like your clutch dog is shot. They are not cheap. The dog and gear have precisely machined edges, and when rounded, cause the outboard to jump out of gear, especially at higher RPMS. Its failure is due to improper adjustment or worn shift linkages, but usually due to improper slow shifting, those precisely machined sharp edges of the lobes become slightly rounded causing the problems you described. Snap the shifter into gear as quickly as possible with a sure deliberate movement. Slowly shifting into gear causes the gears to slam and bang against one another, rounding the edges of the lobes.

Re: 25 horse '72 Johnson slipping out of gear

HighTrim said:

Welcome to iboats.

It could be something different, but unfortunately, it does sound like your clutch dog is shot. They are not cheap. The dog and gear have precisely machined edges, and when rounded, cause the outboard to jump out of gear, especially at higher RPMS. Its failure is due to improper adjustment or worn shift linkages, but usually due to improper slow shifting, those precisely machined sharp edges of the lobes become slightly rounded causing the problems you described. Snap the shifter into gear as quickly as possible with a sure deliberate movement. Slowly shifting into gear causes the gears to slam and bang against one another, rounding the edges of the lobes.

Click to expand...

Thanks HT. I had heard that it might be the clutch dog. Am I going to have to buy a new clutch dog and gear or just a clutch dog. Any ideas on where to order a new one online?

Thanks

Re: 25 horse '72 Johnson slipping out of gear

it is recommended to change both gears and clutch dog. but open it before ordering. you may have got lucky, as http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

says they have a limited supply, go there, and look up your motor, gearcase.