'64 75hp Starter Bracket Bolt Hole Stripped

Evinrude Boater

Evinrude Boater

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I had the starter rebuilt for my 1964 75hp Speedifour. When I put it back on the motor I found the bolt hole stripped for the lower support bracket bolt. I think it bolts through the front crank case into the cylinder block. It's so low on the engine that it's hard to get at and I don't think I want to have it tapped out for fear of damaging it more. I hope the crank case seal doesn't rely on that bolt. Should I bother trying to get that bolt tight or will the starter be fine bolted through the upper mount into the starter drive?
 
JB

JB

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

Drill it out with a 1/4" bit, then tap it for a 5/16" bolt. Open the hole in the mount with a 5/16" bit and use a 5/16" bolt. That is, of course, if it was a 1/4"X20 bolt in the first place. If it was a 5/16" before, go to a 3/8".

Don't run the engine with a bolt loose or missing.
 
Evinrude Boater

Evinrude Boater

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

OK, I bought a 5/16" 18NC tap and a handle. I hope I can get in there. Could I use a 1/4" drive socket extension backwards in the T-handle and put the tap in the other end of the extension so that I'm not banging up against the crank case or lower engine cover?
 
L

Lodgepole

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

Be careful not to run the tap in too deep and too hard and punch a hole in the crank case. It might be wise to get some good clean threads started and then use a bottoming tap to clean out the threads deep in the hole. Or you might grind away part of the tapered tip of the tap (after you get good threads established) to make the threads cut deeper into the hole.

You can probably find a 1/4" drive 12 point socket that will fit the shank of the tap and then use a 1/4" ratchet to turn it in the tight place. This sometimes works for me.
 
Evinrude Boater

Evinrude Boater

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

Lodgepole said:
Be careful not to punch a hole in the crank case.
Click to expand...

Thanks for the warning. I think I'll measure the existing depth and mark that on my 5/16" drill bit and tap so I don't go too deep.
 
JB

JB

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

Don't use a 5/16" drill to drill for a 5/16"X18 tap, EB. The 5/16"X18 tap starts with a 1/4" hole.
 
Evinrude Boater

Evinrude Boater

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

JB said:
Drill it out with a 1/4" bit, then tap it for a 5/16" bolt. Open the hole in the mount with a 5/16" bit and use a 5/16" bolt.
Click to expand...

Ah yes, I re-read and see the error. Two drill bits required, 1/4" for the engine block and 5/16" for the starter bracket. Thanks for catching that, I didn't. This weeked is supposed to be in the 50s so I'll probably get at it then. Keep your fingers crossed.
 
Evinrude Boater

Evinrude Boater

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

Good news, the hole was 1/2" longer than the bolt so I put a longer bolt in and tightened it down. I couldn't get my drill in there without dropping the lower motor cover.
 
tashasdaddy

tashasdaddy

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Re: '64 75hp Starter Bracket Bolt Hole Stripped

that was probably why it stripped. someone put the wrong bolt in the hole.
 
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