Propeller compatibiliy Evinrude 77 70hp and 74 115hp

[Bubbasboat]

I have a 1974 Evinrude 115hp Model # 115493B that is totally shot and being replaced by a 1977 Evinrude 70hp Model # 707739.

Will my very nice near new stainless steel prop from the 115hp fit the 70hp?

 

[racerone]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

The prop will attach to the 70 HP motor but may not fit the boat.----------You will need to determine if it is the correct pitch for the installation !!

 

[eavega]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Size-wise it will fit. Both motors should have 13-spline shaft, large gearcase, thru-hub exhaust.

As the racerone said, your motor may be hard pressed to turn your prop at the proper RPM depending on your setup and the pitch on the prop.

Rgds

Eric

 

[roonie]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Bubbasboat.....are you having any issues with your 70hp. Many of that yr. and hp have trouble accellerating/transitioning from low jet to high jet. I have the exact yr. and hp engine. If you are in fact having this issue and have solved the mystery please tell us how you fixed it...if not.....just hit the choke when she starts to stumble and you will be gone.

 

[boobie]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

What's the dia and pitch of the prop ??

 

[boobie]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Roonie there was an OMC service bulletin out on the '76 motor where you could drill and re jet the carb for that motor with that problem. May want to check with an old BRP dealer. He may have it.

 

[Bubbasboat]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

My hull is 73 0r 74 Glasspar V165 16.17'. How would I determine the proper pitch for this hull/motor combination? I've been trying to post photo's all day to no success. Is the pitch stamped on the propeller?

 

[jimmbo]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

the dia and pitch, on OMC props is usually on the end of the huh where the prop nut goes. Props suitable to run on your engine will allow the WOT rpm to be at or near the top of the WOT rpm range. On your engine that is 4500-5500. Different gear ratios on the various hp engines, allow the same props to be used on the same boat, not always but quite often

 

[Bubbasboat]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

No I have not. I have just bought the motor, mounting on hull tomorrow. I will definitely keep this very interesting point in mind once I get to push the throttle! Believe me, I can't wait for that moment!!! Could we start a thread on this subject, seems it would be of interest to anyone running this motor, seems a shame to bury it in an unrelated post. If you do start a thread, please message me so I can follow the thread. What are your thoughts about my prop proposition?

Bubbasboat.....are you having any issues with your 70hp. Many of that yr. and hp have trouble accellerating/transitioning from low jet to high jet. I have the exact yr. and hp engine. If you are in fact having this issue and have solved the mystery please tell us how you fixed it...if not.....just hit the choke when she starts to stumble and you will be gone.

 

[roonie]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Bubbasboat...there was/is a thread started already on here ....somewhere. Lots of guys chimed in on the thread. The conclusion was drawn that drilling the jets out was not the answer to many engines like boobie stated above on this thread. I will see if i can find the thread and send it to you via pm.keep in touch and let me know when you get er up and going. good luck...sorry im a new boater guy...worked on lots of cars all my life but this boat stuff is all very new ...and interesting so for me to advise me on your prop.....you might end up at the bottom of the lake.....hehe.

 

[Bubbasboat]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Yes, please send me the link to forum post, that would be great! I will be posting more on this motor as I go along.

 

[Bubbasboat]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Printed on the hub of the prop currently installed on the 115hp is, 013 1/4 X 15 Turbo, a spare I have has 13 3/4 X 15 and the 70 hp currently has a 13 3/4 X 15, the spare is a 13 spline shaft. Sorry for delay in info and photo's, had upload issues. Photo's attached. Also dia is 3.5"

What's the dia and pitch of the prop ??

 

[Bubbasboat]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

Thanks, I found the numbers exactly where you said. 013 1/4 X 15. Regarding "On your engine that is 4500-5500" are your referring to the 70hp or the 115hp? I'm going to look at gear ratios now to see, and I understand the hull is still a part of the equation.

the dia and pitch, on OMC props is usually on the end of the huh where the prop nut goes. Props suitable to run on your engine will allow the WOT rpm to be at or near the top of the WOT rpm range. On your engine that is 4500-5500. Different gear ratios on the various hp engines, allow the same props to be used on the same boat, not always but quite often

 

[Bubbasboat]

Re: Propeller compatibiliy Evinrude 77 70hp and 74 115hp

I believe my original question has been answered. My props are interchangeable, if the pitch is proper for the hull and motor. That is a question for another thread. Thank you all!!