1974 9.9 Johnson

[dew2]

I bought this motor not running 1974 9.9 Johnson Mod 10E74S.
I was told a mechanic said that year had problems with exhaust and it was hard to tune correctly. Has anyone heard that? Did these engines have any problems that are known.I have gone through it and have it ready to test.At below zero temps its hard !but in a month I should have a test tank that wont freeze.Looking ahead.Thanks for any replies.

 

[bktheking]

Re: 1974 9.9 Johnson

Not sure about that , the exhaust "design" on that motor remained unchanged for over a decade. 74-76 are my fav motors in the 9.9 stable, all metal design and pretty reliable with the points setup. The only issue with an older engine like that- possibly low compression , possible bad seal at the top of the water tube, the other picky part were the tiller gears. The didn't have a telltale however one is easy to add. I wouldn't run it below zero, wait till it warms up.

 

[F_R]

Re: 1974 9.9 Johnson

"Hard to tune" is an understatement.

I was a dealer mechanic in 1974. We had terrible luck with the 9.9 and 15hp motors under certain conditons, especially when used as sailboat auxillaries. We couldn't keep them running one weekend. OMC came out with several kits that were supposed to correct the problem, but none did.

On the other hand, used on different boats, they were fine.

But the experience left me with a bad taste in my mouth.

 

[samo_ott]

Re: 1974 9.9 Johnson

Dang. I just picked up my first 9.9 in the fall (a '74!). And sure enough it has tiller problem gears and didn't idle right! Hmmm.