1955 evinrude 7.5

[bktheking]

So I got this motor running tonight, seems whoever put the carb back together after they put a kit in it forgot to put the clip on for the needle, duh, the thing fired up first pull. Not a bad motor for $70. Now the question I have, on all my other motors, 9.9 and 9.5 there is a detent for the shifter to make it shift positive, you know where neutral forward and reverse are cause you feel it. With this motor there is no positive neutral forward or reverse, i don't feel the click as I move it from neutral to gear. I know it's going in gear cause if I do shift it and turn the prop the flywheel moves. Maybe that's how they were designed back then but I don't think so.


My other question- where does the water come out to show that its pumping, it looked like it was coming out from the bottom of the head. Sound about right ?


Any thoughts and thanks for replying.

 

[bktheking]

Re: 1955 evinrude 7.5

OK so I watched some video's of 7.5's on youtube. It appears that the water on all the other motors comes from the middle of the lower unit, there is indeed a hole for it. Looking the bottom and top of the head on mine it appears as if a frost plug used to be in the bottom but now it is gone. Are the plugs available and should I put it back in to have it route properly.

Thanks

 

[samo_ott]

Re: 1955 evinrude 7.5

No water should be coming out from the head area. As mentioned, it exits with the exhaust about halfway down the leg.

As for the detent. There is none to speak of. None of the earlier engines have it. From what I have seen it started in the early 60's. They put a ball bearing on a spring in the LU to have the detent position.

The old ones like you have have the rod above the shift handle to roughly hold it in place. It works ok.

 

[F_R]

Re: 1955 evinrude 7.5

The detent on a 7.5 (and 5.5) is a flat spring that engages notches on the side of the shift rod---INSIDE THE GEARCASE. You should be able to feel it click in and out of the gears. If you can't, somebody has been in there and left the spring out. If that is the case, it will flop around loosy-goosy.

The core plug on the bottom of the cylinder head is famous for rotting out. It is easy to replace on the '55. It is fairly easy on the '56-58 also, just remove the lower rear pan for access on those.

The water is supposed to blow out the big hole in the rear of the midsection. If it is all escaping out the cylinder head core plug, the exhaust housing probably will get pretty hot because the water isn't spraying through it to cool it.

 

[bktheking]

Re: 1955 evinrude 7.5

No I can't feel anything, it is rather loose and kinda just flops around. So I'm assuming powerhead has to come off , do you have a diagram of where this spring is F R?

Is the core plug a standard OMC part still?

Thanks

 

[samo_ott]

Re: 1955 evinrude 7.5

Dang. He's right again. I never realized the detent was in the 5.5 and 7.5's but not the 10,15 & 18's which I work on the most. See you learn something everyday! Here's a pic of the '56 E7.5 LU. The detents are # 49 and #50. And if you look at the lower part of the shift rod just above the bend, you will see the detent in it that it clicks into. In the few 5.5 and 7.5 LU's I have done these parts are usually missing I find (probably in yours also). Thus why I thought it started in later years.

 

[bktheking]

Re: 1955 evinrude 7.5

Thanks for the diagram Samo. So where in gods name do they belong in the gearcase, the diagram kinda shows them floating in mid air and the other big one is can they be purchased??? Maybe John's out here would have them or Laurentian.

 

[bktheking]

Re: 1955 evinrude 7.5

I found the part numbers from another site, it appears that they are still available. And to add some more insight, they are the same springs used in the 1973 9.5 motor.

 

[1946Zephyr]

Re: 1955 evinrude 7.5

You won't need to remove the powerhead to put those springs in. All you need to do is stand the motor on it's top and remove the lower half of the gearcase. You'll probably find a screw hole along side of the indents of the shift rod, where the flat springs once were.

 

[samo_ott]

Re: 1955 evinrude 7.5

Thanks for the diagram Samo. So where in gods name do they belong in the gearcase, the diagram kinda shows them floating in mid air and the other big one is can they be purchased??? Maybe John's out here would have them or Laurentian.

I get my parts from Alfie at Laurentian. They can get pretty much whatever I need I find. Never been to John's. Do they have a good supply also?

 

[bktheking]

Re: 1955 evinrude 7.5

John's has been an OMC dealer for 50+ years, they have alot of NOS parts that no one else has, for you it would be far, for me it's 12 minutes. I find Laurentians prices better though and John's charges $7.50 on top of the price for any OMC parts they order, Laurentian doesn't.

 

[Dave Jarvis]

Re: 1955 evinrude 7.5

Please forgive me if this is not the correct way to ask but I was hoping to see how to remove the lower unti on this motor to replace the water pump impeller. I have done a few but I just dont see how to disconnect the shift rod. If anyone could help me I would surely appreciate it. Again, I apologize if this is not the appropriate place to ask.

 

[lindy46]

Re: 1955 evinrude 7.5

You should start a new thread. But anyway, on the 7.5hp motors you have to remove the powerhead to get to the shift rod to discoonect it. It was a 1-piece shift rod instead of the 2-piece on most other models which were easily disconnected on the mid-section of the engine.

 

[samo_ott]

Re: 1955 evinrude 7.5

Yes, that is the weakness with the 7.5's and 5.5's in my mind. You have to remove the powerhead to unhook the shift rod. It's not as bad as it sounds though. There's 6 or 8 screws on the bottom to undo, remove the fuel hose and it comes right off. You might need a new powerhead base gasket though. sometimes they rip when it comes off. Sometimes not. Also you should replace the cork gasket at the top of the driveshaft under the crankshaft.

 

[Dave Jarvis]

Re: 1955 evinrude 7.5

Thanks a million, I was pulling my hair out. I am so glad you could help me out before I made more work for myself. I need to find out mre about how to use these forums appropriately. You folks are the best !!