Replacement Powerhead Mounting Bolts...?

[MattinTally]

I have an '88 90hp 3Cyl that I took the powerhead off to. When I removed it, I had to cut all of the mounting bolts from the midsection that held the powerhead onto the mid section.

They are each about 8" long, hex-cap bolts with a flange around the hex cap. The bolts are solid, except there are threads on the last 1" or so of the bolt.

Where do you get replacement bolts from? I've looked online, but had no luck. Maybe they aren't called "powerhead mounting bolts"...

 

[saumon]

Re: Replacement Powerhead Mounting Bolts...?

http://www.ishopmarine.com/ishop/js...For=29&req4Browse=1&docId=365&docName=MERCURY | 1988 | 90 | 70/75/80/90 HP (3 CYLINDER) - 1090312BD&isForSupStore=true&cCatFilter=MM&eCatSupFldr=supplier-050-025-MM

Look at #15 (bolts), wich is replaced by 15A, 16 & 17 (studs, washers and nuts)

 

[Chris1956]

Re: Replacement Powerhead Mounting Bolts...?

The ones on my '77 Merc 1500 were 6" fine thread grade 8 bolts, 7/16" in diameter with grade 8 nylon lock nuts. I found them at a store called the "Bolt Bin", for $3-4 ea. Merc had them for $12 Each. The Home Despot did not have them.


Make sure you get identical replacements. You do not want the motor to fall off the boat.

 

[MattinTally]

Re: Replacement Powerhead Mounting Bolts...?

What I have are BOLTS..... only bolts..... No washers.... No Locknuts.... Just bolts. Hex Cap w/ Flange @ one end..... and threads at the other tip. Threads do not go the entire length of the bolt shaft.... just 1" at the very tip.

Do I need to convert to something else..... OR..... after reading your post...... just find any ole hardware store w/ Grade 8 stainless bolts w/ the same thread pattern and just use those?

And as usual, thanks for all your help & advice.

 

[Chris1956]

Re: Replacement Powerhead Mounting Bolts...?

Stainless Steel is not graded the same, however, the best grade of SS is about grade 5. Check the heads of your old bolts and get the correct replacement. If you have grade 8, replace with grade 8. Any source is fine, and probably the length of the threads is not important.

 

[MattinTally]

Re: Replacement Powerhead Mounting Bolts...?

10-4. I checked Lowes while I was there over the weekend buying other stuff. They didn't have anything. The closes was a 3/8 bolt.... but the threads are different.

I'll take it to our local Ace which usually has a much greater selection of specialty bolts and see if I can get a match.

 

[MattinTally]

Re: Replacement Powerhead Mounting Bolts...?

Took one of the old bolts to Ace & they had the correct pitch bolts in Stainless, but not long enough. Knowing the pitch, I searched the internet using Google and located what I needed and ordered online.