Is the rebuild worth it? 1974 9.9 Johnson

Hey everyone! Attempting to do my first rebuild, and I've got it torn down so far.
It's a 1974 Johnson 9.9

Just looking for some input (still very new with motor repairs).

Issues encountered so far:

• Bearing Housing on the lower unit is cracked/broken at both bolts (will need to be replaced - minimum $50?)
• Several bolts on the powerhead sheared off during disassembly (haven't put any effort into getting them out, but could cause issues)
• Top piston head has some damage? (In picture below)
• Coils are super rusty (Is this an issue?)
• Carb has a crack in it from somebody trying to unbolt it (looks like they attempted to seal it) (Is this no good?)

So, at a minimum I think I'm looking at:

• New gasket kit/set ($50)
• New/used bearing housing ($50+)
• Misc cleaning supplies ($50)
• Paint/primer/sealant/antisieze for bolts ($75-$100?)

I've never done any work with teardown before, so I'm not sure the extent of this damage/if it will cause minor or major issues in the long run?

Mainly, I was just wondering if the rebuild is worth it, or should I sell the motor for parts?

Any input is appreciated!

Thanks

Hi Johnny.
Whether it's worth it or not is really only depending on several factors:
Are you doing this to learn as a "hands on" kinda experience, without really caring about money and time spent on it?
Then yes, it's worth it.
If you are wondering about whether or not it makes economical sense to spend hours / days, and probably a few hundred bucks in parts to rebuild a 74 (magneto ignition) motor, then IMHO the answer is NO.
These motors are readily available on the used market (CL for example) for a few hundred, and as long as they have a good compression reading, will likely only need a water pump, carb kit and fresh LU oil to get running. On top of that I would definitely go with the post 76 motors (77 and up) as they have the CD ignition and are much better for that reason alone.

Thanks for the input!

I am doing it as a hands on learning experience, but that being said, if I do put a fair bit of time and money into it, I would like the product of that effort to be something reliable and dependable! I.E if there are problems with these magneto ignitions, it would be disappointing to completely rebuild it and have it not running well after only a few hours of run time...

I'm up in Ontario Canada, there are other motors around, but not a ton, and generally too expensive for a "learning" experience. I'm leaning towards seeing if I can get some money out of it for parts.

JohnnyBouy said:

I'm leaning towards seeing if I can get some money out of it for parts.

Click to expand...

I'm in violent agreement with you there.... not to say that all magnetos run poorly, I had a 1976 Johnson 9.9 that was running great, but always ended up fouling a plug at one time or another (so much for the "reliability" factor). They were notorious for that. I have never had this problem with the CD ignition.

Can you get oversize pistons? Is the crank and bearings in good condition? The upper cylinder needs to be bored over you should do both the same. Do you have a good machine shop to do the work? You can get a good used 25hp carb for reasonable as well as rebuild the gearbox. IMO the cost of the shafts is what will condemn a engine. Price oversize pistons and availability?

Why would you mention a 25 hp carburetor here ??----Wiseco has replacement pistons and the mandatory wrist pin bearing kits.----In Ontario you are better off financially finding a 1985 model or newer.

Typo meant 15hp

Yep Johnny if it were me, I wouldn't put good money after bad on that one from what these guys say about that type motor. Good luck

A newer motor with CDI is a better bet. I've had some cooling issues with my '79 Evinrude 9.9HP. After I got those solved it's been a really solid motor.

KJ

I got my 76' in a box for 100 bucks. Good block. Bought a 1989 head for it.. had to trim the cowl to fit the thermo housing. Modded the intake to match the 93 and up. Trimmed some of the low to mid throttle cam to slow the opening with respect to the timing. Back cut the main nozzle on the carb to delay main jet feed and jetted according with ngk b5 plugs Added Boyessen reeds and Wiseco pistons with appropriate clearance. But does have the stock ignition.

Now it runs real good...400 bucks later

me not, but whatever, you can do whatever you want, I guess, it's pretty late to say something.