1960 Starflite 75 Slipping Gear

[bassbonebobo]

I've got a 1960 Evinrude Starflite 75 O/B. It runs great except for one quirk. Occasionally when running full open it will slip out of gear and then slam back into gear. It is all quite sudden (maybe a second from slipping out to coming back in). There is a loud "wham" when it goes back into gear and the boat shudders. The first time it did it I thought we had hit a dead head. Where should I start looking for the cause? Any one seen this on this (or a similar) engine?

 

[R.Johnson]

Re: 1960 Starflite 75 Slipping Gear

Does it have the electro-matic gearcase?

 

[lindy46]

Re: 1960 Starflite 75 Slipping Gear

Worn clutch dog/forward gear in the lower unit. These will have to be replaced and are expensive to buy new. Better to get a good used lower unit and swap it out.

 

[bassbonebobo]

Re: 1960 Starflite 75 Slipping Gear

Worn clutch dog/forward gear in the lower unit. These will have to be replaced and are expensive to buy new. Better to get a good used lower unit and swap it out.

Well that doesn't sound good at all. I priced out the replacement and they will run close to $500. How much do you think a decent, used lower unit should cost? I will have to pull the lower unit this weekend and inspect it. If I were to replace the clutch dog but leave the old forward gear how much damage am I risking to the rest of the engine (assuming the gear passes a visual inspection)?

 

[lindy46]

Re: 1960 Starflite 75 Slipping Gear

The clutch dog and gear surfaces must exactly mate to work properly. They tend to get rounded off over the years, especially if the shift lever is not firmly and quickly engaged. Replacing one and not the other won't cut it. Check for lower units or gearsets on Ebay or go place a want ad at AOMCI:
http://www.aomci.org/cgi-bin/yabb2/YaBB.pl?board=Webvertize
Good luck!

 

[Chris1956]

Re: 1960 Starflite 75 Slipping Gear

Bass, You have a manual shift gearcase?

Some of those manual gearcases use identical gears for forward and reverse. If your has this feature, you may turn the shift dog around and swap the forward and reverse gears. Make sure you keep the idle speed as low as possible to help the gears last.

 

[bassbonebobo]

Re: 1960 Starflite 75 Slipping Gear

Chris,

It is the manual gear case. I will have time to remove the lower unit tomorrow. It is hard to tell from the blow up in my service manual if the gears are identical but they very well could be. If that's the case than it looks like I may be able to buy a few more years on this engine.

 

[R.Johnson]

Re: 1960 Starflite 75 Slipping Gear

One gear has a pressed in bushing , the other is a running bushing. You would have to press the bushing out, and change them around in this case. In this case I'm just saying the gears are not the same. It's been to long since I've worked on one of these gearcases to say if it can be done. I know it would not be recommended