1960 Evinrude Starflite 75 HP - Help

[bnelson79]

To begin with, very NEW to boating. Bought a 1971 Glastron that has a 1960 Evinrude Starflite 75 HP motor on it. She starts. I replaced all the plugs, changed the lower unit oil put some fresh gas and oil with a can of sea foam (suggested by a boat repair guy). Got her out last night and she starts just fine. When I put it in gear it appears to kick itself out of gear. Also when I can keep it in gear the motor makes a thumping noise which there no pattern to, just randomly does it and actually shakes the back of the boat a bit. The sound is similar to the sound when I put it into gear. I was not able to get it up to high speeds due to this thumping or shaking but when I increased speed the thumping or shaking was occurring more rapidly. It also stalls when I try to put the boat in reverse. Again, I am very new to this. Didn't pay much for it so I am not into much here. Again, she fires right up, when in neutral if I rev the engine it appears to sound and feel normal.If anyone can give me any insight on what this could be and if this is something major that would great. Looking for a new hobby but don't want to break the bank either. Thanks for reading!

 

[sutor623]

Re: 1960 Evinrude Starflite 75 HP - Help

Where you located? Just curious. Does the thumping sound like it is coming from down low? You may have a misfire of some sort. I'd also check the shift linkage. Undo the linkage and shift into F-N-R. Does it still kick out of gear? How was the L/U oil when you pulled it out? Any metal shavings or water? Sounds like there is the possibility of some worn out gears in the lower unit.

 

[F_R]

Re: 1960 Evinrude Starflite 75 HP - Help

You said that it kicks itself out of gear. You can just about bet the farm that the forward gear and clutch dog are hopelessly worn out. And have been for a long time. Continuing to run it like that often beats the shift linkage to death too.

Expensive repair?? You bet.

 

[bnelson79]

Re: 1960 Evinrude Starflite 75 HP - Help

Where you located? Just curious. Does the thumping sound like it is coming from down low? You may have a misfire of some sort. I'd also check the shift linkage. Undo the linkage and shift into F-N-R. Does it still kick out of gear? How was the L/U oil when you pulled it out? Any metal shavings or water? Sounds like there is the possibility of some worn out gears in the lower unit.

I am in Wisconsin. The water levels are low here and I thought at first the motor was hitting the bottom of the lake when I launched. But when I got it in deeper water it continued. It does appear to be coming from the lower part of the motor. The L/U oil did look ok when I drained it... just normal color no shavings etc. I will undo the linkage and see what it does. The L/U does appear to be newer or replaced at some point as well. Not sure when that was done.

 

[bnelson79]

Re: 1960 Evinrude Starflite 75 HP - Help

You said that it kicks itself out of gear. You can just about bet the farm that the forward gear and clutch dog are hopelessly worn out. And have been for a long time. Continuing to run it like that often beats the shift linkage to death too.

Expensive repair?? You bet.

Thank you for replying. How do I know for sure if that is the problem? Any way to test that? When you say expensive, what are we talking for something like that roughly?

 

[Chris1956]

Re: 1960 Evinrude Starflite 75 HP - Help

IS that motor a mechanical shift? If so, you can probably reverse the two gears and clutch dog. There is a small chance someone has not already done that, and it may fix the issue. You need to adjust the shift linkage per spec, or it will likely go bad again. The shift linkages getr lots of play in them from wear. That can mess stuff up also.

I had a motor similar to that with the same issue. I ended up adjusting the shift linkage all the way to engage forward. I had no reverse, but forward worked fine.

 

[bilbo1usa]

Re: 1960 Evinrude Starflite 75 HP - Help

Bnelson,
Chris1956 (above) has it right. Those are great solutions.

Attached are a couple pictures of the dog gear and the one of the two directional gears (I think the pictured one is the reverse gear)
They show the wear that is causing your problem; at the point where the dog gear contacts the direction gears there are 2 posts (dogs).
They will become rounded at the tips and allow the boat to slip out of gear, it will create the boom/bang you are talking about.

Be warned, this will also eventually cause your prop hub to spin, or the sheer pin to snap (voice of experience here).

The part numbers for these three gears are :
307095 - dog ring gear
307074 - Reverse gear
377870 - Fwd gear

If you Google one of those numbers, or better yet, put that number into ebay, you will receive the shock of your life. They are in the hundreds of dollars for each gear.
Take caution buying used gears...This problem is intrinsic in every motor of that year and type, and most used gears will have that wear...to the degree that Evinrude released an engineered 'fix kit' to solve the problem to their dealers mid 1960, and eventually changed the design a bit.

Dog gear:


One of the direction gears:


Be prepared for a battle. I have fought this issue for years as I'm too cheap to buy the gears for that motor.
PM me, or post issues if you have questions about the motor, as I've fought about every problem you can have with this motor, with the help of the awesome members of this forum.

As mentioned before, adjusting the shift linkage all the way into forward will really press the dog gear into forward and eliminate reverse, but is a good work around if the gears aren't too badly damaged(it's what I have done too).
Bill

 

[jimmbo]

Re: 1960 Evinrude Starflite 75 HP - Help

Those pics show what damage 'easing slowly it into gear' does.

 

[bilbo1usa]

Re: 1960 Evinrude Starflite 75 HP - Help

Heh,
I wish it was that simple.
I was told from the get go to slam this baby into gear, and have always done so.
But who knows what they guy before me did!

That's another useful tip for bnelson or anyone else who has this era motor...slam that baby into gear, don't ease it in, like Jimbo said.
Good point!
Bill