Mainship 34 rebuild/repower

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Woodsong

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Oct 7, 2007
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Bayliner 4550 Pilothouse
A good friend sent me a link to a site detailing the full repower and refit of a 1978 Mainship 34. *Pretty amazing how much work they did to her and full details, pics, specs, etc. of the refit and repower. *Check it out- thought you all here at TF would enjoy it:
http://www.mainship34.com/index.php

Click on the repower stuff- very interesting and detailed. *300hp seems like a lot of hp for that boat but looks like they did hit a world speed record for a Mainship 34 @ 20 MPH.


-- Edited by Woodsong on Thursday 13th of January 2011 12:07:44 PM
 
WOW.**Holy cow they tore that boat apart!* I'm still looking for the photos of how the interior turned out...
 
Woodsong:* Nice link.* We use to have a 1981 34' Mainship that had the Perkins turbo.* That would move the boat along at 12 knots and 8-10 knots pretty comfortably.* There was*a big group of the early Mainship owners in the PNW and 2 had re-powered with engines rate at around 210 hp.* Those got up and moved.* I imagine the 300 hp Cummins would be a heck of a ride.*
 
Here is a video of him going WOT:


I posted earlier that he got up to 20 MPH. I was wrong- they did 20 knots so about 23 MPH and about 15 GPH. Not bad. I could not imagine getting my trawler to go that fast!!

Pineapple- I didn't really see any finished interior pictures either but he sure did everything else possible. Whenever I think I am spending too much money on my Monk I am going to go browse that site again to make myself feel better!! :)

-- Edited by Woodsong on Thursday 13th of January 2011 12:13:31 PM
 
I did a similar 1978 Mainship 34 repower from a Perk 160 to a Cummins 6BTA 270. That was in 1999.
Top speed for me with the new power was 18.5 knots (21 mph) , and I used to cruise at 12 knots at 2000 rpm and that was using about 5 gph.
The issue with the old Mainship 34s is that anything over 16 knots gets squirrelly.
 
Tony, I was docked in St. Augustine beside a Mainship 34 II from Jacksonville.* The guy worked for the Cummins dealer in Jacksonville, and had repowered with a Cummins 300HP.* It was set up for offshore sports fishing, and I understand that he was an avid fisherman.* He said he could cruise at 17-18 knots.* Not verified by me.* Looked like a pretty good outfit.
 
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