1974 Johnson 9.9 model 10EL74 - just bought / questions from a novice

[fireflimoon]

Hi

I just bought an old johnson and it does start and run in a barrell of water. It seems inevitable that these oldies have pieces from various places since time naturally takes it tool but I was wondering if there is anyone that could clarify something the seller told me - not sure if he was hinting something about the motor or not.

He mentioned to use a 40 to 1 ratio for the fuel which seems different from the 50 to 1 ratio I thought was normally used.

Does this "hint" suggest something about the state of the motor? I am thinking low compression but maybe something else is the cause for this hint. Will be getting the manual and service catalog/users manual.

In the meantime I will be poking around. If anyone has any poking around suggestions please let me know....

Thanks in advance....

 

[TN-25]

Re: 1974 Johnson 9.9 model 10EL74 - just bought / questions from a novice

50:1 is fine on that motor, but the previous owner is saying that it is better to err on the side of caution. Really those motors are fully jewelled, meaning ball bearings throughout the powerhead & reciprocating assembly. OMC even rated those motors to run at 100:1 in the 1980s but later recanted.

Here is a link to a bunch of stuff covering the Johnson / Evinrude 9.9 - 15 from 1974 through 1992: http://www.sschapterpsa.com/ramblings/Ramblings.html

BTW, Welcome to i-Boats!

 

[OptsyEagle]

Re: 1974 Johnson 9.9 model 10EL74 - just bought / questions from a novice

I agree. Some people just like to use more oil. Doesn't need it but won't hurt it either.

 

[fireflimoon]

Re: 1974 Johnson 9.9 model 10EL74 - just bought / questions from a novice

Thanks guys...

I'm going to look for how to test compression anyway since I have a compression tool I inherited but don't know how to use it - I could remove the spark plugs and pull the rope but I think I read somewhere that I could harm a coil doing that if I didn't ground it properly.
Will check thread and link given.

Thanks a bunch....

 

[jasper60103]

Re: 1974 Johnson 9.9 model 10EL74 - just bought / questions from a novice

Thanks guys...

I'm going to look for how to test compression anyway since I have a compression tool I inherited but don't know how to use it - I could remove the spark plugs and pull the rope but I think I read somewhere that I could harm a coil doing that if I didn't ground it properly.
Will check thread and link given.

Thanks a bunch....

Yep, make yourself a jig for grounding the spark plug wires.