bertram31.com

Restoring 31FBC that had gassers. Repowering with Cummins 6BT 300hp and wanting to upgrade to 1 1/2” shafts. Who is best supplier for struts. Or can my old ones be bored to accommodate larger shafts?

I used HIGH TIDE MARINE for my new struts. My original struts were bored to handle 1 1/2" but they failed years later. Had a crack in the barrel where the cutlass bearing goes. Had to replace both as we could not get a match to the new one. You are probably looking at replacing both. My boat was like yours as it was originally gas and changed to diesel in 2002 I have Yanmar 6LP 315 hp. Nice people to work with at HIGH TIDE.

Thanks for the help. We’re they custom built or a stock item?

I still have original struts. Running 5.9 BTA Cummins 270 Hp with 1 1/2 Aquamet 22 shafts 83 1/4” EOT 6,000 hrs. Never a problem. What we did to accommodate the larger diameter shafts was machine Morse Flatfish Cutlass bearings to 1.88” O.D. They slide tightly into the strut. I have to be very careful when drilling the keeper set screws through the strut housing into the cutlass, all you need is a dimple with the drill bit into the outer cutlass housing to hold the SS set screws tightly. No need to buy new struts only if makes you happy. Neil does the same. EarleyBird

I went 1 3/4” shafts when i put in my Cummins 370’s and purchased new struts from Danny at Hightide and he bored them out for me he had them to me quickly. I have seen plenty of these guys bore out originals and get smaller diameter cutlass bearings and be fine with 1 1/2” shafts.

Can anyone give me a short course on posting pics on this site? Tried following instructions but at 69 my computer skills are somewhat remedial.

Another option to opening the strut bore so much or turning the standard cutless bearing shell is using Thordon for the bearing. Less friction and they do not require an outer shell (brass or phenolic) giving the ability to go really slim.

Thanks for all the info guys.

I also had my originals bored out and then had a thin walled gutless bearing installed. I am running 270 hp Cummins, same as Early Bird.

https://imgur.com/a/ExL0io7

Test run on image posting.

Test successful, looking good!