Help removing zinc from Alpha one

[Fishermark]

I need to replace the trim tab zinc on my 1988 Mercruiser Alpha One. The bolt holding it in is supposed to be a 3/8" allen bolt which you get at from the top. My bolt is apparently stripped. There is quite a bit of corrosion and debris in the cavity where you access the bolt head. After cleaning and blowing out what I could I discovered the 3/8" Allen wrench I have turns in the top of the bolt head. What's the best method for removing this? Drill out the bolt from the top? Cut out the zinc from below with a cut off wheel? Acetylene torch? Suggestions?<br /><br />On a related matter, I will obviously need to replace the bolt as well as the zinc. I understand the housing is designed so that the bolt stays in the top, and doesn't come out, meaning I would have to remove the foot to replace the bolt. What's the downside of simply drilling the top access hole large enough to remove and replace the bolt, then putting a larger plug back in?

 

[Trent]

Re: Help removing zinc from Alpha one

The internal wrenching bolt could be slightly worn. Try a metric allen wrench. Also the bolt should come out without removeing the lower unit. Also the zincs are sort of brittle and can be broken up with a old screw driver or chizle. Becareful breaking it up. It can be done.

 

[Fishermark]

Re: Help removing zinc from Alpha one

Thanks, I'll try the metric wrenches. I know the new bolt I bought will not fit into the hole. The head is too large - and I believe it is the same size as the original. (I think they did that so that you will not lose the bolt if the zinc falls off?? )

 

[rodbolt]

Re: Help removing zinc from Alpha one

hello<br /> looks like a perfect oppertunity to change the water pump. I have seen the hole enlarged but never tried it myself. its rare that I reengineer things. Trent careful the typing Po lice alredy done busted me fo slatterin da anglish langage. . yall have fun and keep postin ya heer.<br />and yes I grew up in Mobile

 

[Fishermark]

Re: Help removing zinc from Alpha one

I don't really need the waer pump as I have a thru huill fitting and raw water pump. I keep the water flowing through the outdrive to keep it cool, but it pumps fine. I really don't want to mess with removing the lower unit right now.

 

[Trent]

Re: Help removing zinc from Alpha one

Give me a break.....I work for a living! I never said I could spell! Im a hundred miles north of Mobile....Guess that makes me one of them northern boys God help me!!

 

[airman]

Re: Help removing zinc from Alpha one

I just had the very same problem with mine. Cut the bottom of the zinc off to expose the bottom of the bolt. Heat with an acetylene torch for about 30 seconds. Punch the bolt up from below - it will pop right out. To change the bolt you can enlarge the hole but it will fall right out if you split the leg. If you have a torch it's an easy job.

 

[Fishermark]

Re: Help removing zinc from Alpha one

Thanks Airman,<br />I will work on it today and post a report on how it went.

 

[Fishermark]

Re: Help removing zinc from Alpha one

Well, that was quick and easy! It took just a few minutes. I cut the "tab" or "keel" off with a cutoff tool and exposed the bottom of the bolt. Heated it like was suggested, and sure enough the bolt popped out. Nice and clean! Now I just have to decide whether to separate the lower unit or enlarge the hole...

 

[elpaso]

Re: Help removing zinc from Alpha one

Enlarge the hole - it works.

 

[Fishermark]

Re: Help removing zinc from Alpha one

Here's the final post - I did in fact enlarge the hole. No problems. Works fine. Thanks for all the help.