Is this fixable?

[JASinIL2006]

In trying to repair a broken starter recoil spring on my 1990 4 hp Johnson outboard (model J4RDHESR), I managed to misthread the bolt that holds the starter swing assembly (the part that swings up to engage the flywheel when pulling the rope) to the side of the engine block. As you can see in the pictures below, I not only messed up the threads, but the casting itself is cracked.

Is this something that can be repaired, short of replacing the entire block? Other than the starter spring problem, and now the problem I've created, the motor has been good and reliable.

Any thoughts?

 

[interalian]

You could have it welded, drilled and re-tapped. That'd be the best way.

If you want cheap, squeeze the blown-out parts back into place with vicegrips, put about 6 turns of mechanic's wire around the stub then twist the wire tight. Butter the outside area with JB Weld. Drill and Helicoil when it's cured.

 

[orbanp]

Well, welding would be the preferred method of the repair.
You would probably need to take the engine apart for that.
You could also check with a welder if this can be welded up in-situ.

As an alternative method, would a sheet metal bracket work, attached under those two bolts that secures the back side of the crankcase to the block? (The bolts show on the left side in the second picture.) You could use a sunken head bolt to attach the bracket to the starter assembly.
The bracket would off-set the height of that broken boss that it replaces by the sheet metal thickness. Would that work?
Would you be able (and willing) to file off that much from that broken boss that all three attachment points would be level?

You could also check how much "meat" is behind that boss, i.e. if the hole can be drilled deeper and tapped without interfering with (breaking through to) the other parts of the engine. Than use a stud, driven as deep as the hole is drilled/tapped.
Would that be strong enough?

You can probably better decide between these alternatives, having all the components there.

Good luck, Peter

 

[flyingscott]

I would get Marine-tex epoxy the gray version. Then i would fill in the cracks and clamp it with a hose clamp.

 

[Chinewalker]

Lot of torque being put on that post when you yank the recoil handle. Epoxy isn't going to cut it. Get it welded and go boating...

 

[JASinIL2006]

Lot of torque being put on that post when you yank the recoil handle. Epoxy isn't going to cut it. Get it welded and go boating...

That's what I thought, too. JBWeld or MarineTex were my first thoughts, but the bolt that goes in that hole is essentially the pivot point that transfers the force from the rope pull up into the flywheel.

I was amazed how easily the fitting was damaged. I mostly finger-tightened the bolt and only gave 2-3 quarter turns with a wrench. Almost made me wonder if maybe that part is cast out of aluminum... I guess I can pull out a magnet and check.

 

[jakedaawg]

Yes, the block is cast Al. Tig weld w/5356 filler. Lots of cleaning first. Use wet rags as heat sink. Use al foil as dam for shield gas. The drill, tap and install helicoil. That's how I just did a starter bolt lug on a force motor.

 

[Scott Danforth]

Yes, the block is cast Al. Tig weld w/5356 filler. Lots of cleaning first. Use wet rags as heat sink. Use al foil as dam for shield gas. The drill, tap and install helicoil. That's how I just did a starter bolt lug on a force motor.

^+1

weld the aluminum with a steel bolt in place, then when it cools, you already have the threads - aluminum wont stick to the steel