1958 Evinrude 7.5hp 7524 Poor Idle

[Kawaiikeno]

Picked up a very nice 1958 7.5hp Model 7524 at auction today.
After checking it all out 92psi compression on both cylinders new champion plugs gaped at .028 It runs very smooth anywhere above the start position, less than that not at all.
I cleaned the carb and all the passages not much change Looking at the points and coils (or whats left of them)
It's clear it needs new coils as the epoxy is actually missing on the tops in spots.
some questions, are they the same coils as the 1955 7.5 and part numbers and where is a good starting point for the mixture screws as it seems to run best under 1 turn out on idle and high speed
Thanks Mike

 

[F_R]

Those cracked coils may very well be the problem. Yes, those coils were used under various part numbers for over 20 years. All interchangeable. 3/4 turn on HS, 1-1/2 on slow speed will get it going.

 

[oldboat1]

Replace the impeller (may need to remove the powerhead unless there is a access port on the side of the leg for the shift rod connector -- but an easy job). Heavier oil mix for the 7 1/2 (16:1). Heavy oil ratio, lean air mix -- final air mix probably around 1 turn open, as you indicate, or maybe a little less. Nice motor.

 

[Rook66]

Use the oil mixture that the factory called for. I've got a '58 model Evinrude 5.5 hp and I've always used what is on the label inside the cowling. And with synthetic oils today you don't even need that much. People using heavy oil mixtures are going to eventually get these old two strokes outlawed on the water by creating a smoke screen on the lakes.

 

[Kawaiikeno]

Thanks for the replies I have ordered new coils, points and condensers and an impeller.
I am surprised at the differences between the 1955 7518 and the 1958 7524 mainly the recoil and flywheel.
Thanks Mike

 

[oldboat1]

http://www.fiberglassics.com/library...service001.pdf 16:1 is the specified ratio. These motors will run with a minimum of exhaust smoke with the factory specified ratios, if the motor is maintained and tuned correctly.

Put in a fresh set of coils (I would do points and condensers as well), and consider disassembly and cleaning of the carb (kits available).

 

[Kawaiikeno]

Example of cracked coils.
It still ran just won’t idle down
mike

 

[racerone]

The magneto in the picture needs new coils.----And those condensers also appear to be 40 + years old.-----Easy fix I say.

 

[Kawaiikeno]

New coils points,condensers,put in a carb kit checked timing with a light, it still doesn't seem to idle as low as it should.
I'm thinking of taking it out on the water and just running it for a while. The spark plugs looked new so I didn't change them that's next
It's too nice to just give up on
Thanks Mike

 

[Crosbyman]

1 DO NOT GIVE UP

http://boatinfo.no/lib/johnson/manuals/1922-1964johnson.html#/0

2- VISIT BOAT INFO the red book has it all...

3- check in with the folks at AOMCI ask a member forum

time it this way...

http://www.youtube.com/watch?v=ga1Cjymj6ms&feature=youtu.be

just in cas re-clean the points and set them as per video

 

[Kawaiikeno]

Just had a chance to work on the 1958 7.5 again I changed the impeller and gaskets.
I'm going to test it in the tank then take it to the lake and try it out
I tried to open the manual listed above but even after updating flash it still gives the flash error
Thanks Mike

 

[Crosbyman]

try this link

https://bit.ly/2wqMPTb

 

[Kawaiikeno]

The 1958 now purrs like a kitten. I'm not 100% sure but when I changed the water pump I noticed the lower crank gasket was bad I made a new one and reassembled it and it now runs perfect

 

[Crosbyman]

great news thanks for your feedback