Lesson learned! Now the questions..

Strychn9ne

Seaman Apprentice
Joined
Aug 27, 2016
Messages
34
I took my '65 Starcraft out the other day, everything was going well until I noticed it was moving slower and was hearing a squealing sound from the engine ('65 Merc 350 35 HP) suddenly. We went back to the landing and pulled it out of the water right away and I noticed the prop was wearing into the lower unit! Took the prop off and found an old style brass thrust washer with no splines in it had been installed on there from the previous owner without the required splined backing washer. The thrust washer had worn into the bearing carrier, and the prop into the lower unit. I originally thought the hub was slipping as the damage is hard to see until you look closer, but it now appears that was not my issue:facepalm:. So, lesson hard learned! Check everything out before using a used boat!!! Luckily I don't see any metal filings in the gear oil and only minimal water came out. I only had it out for about 1.5 hours total. The previous owner had obviously not used it at all or that would have happened to him. The prop shaft still turns freely, so I think I escaped internal damage.

Anyways, I have already began buying parts for a lower unit case swap. I found an NOS bearing carrier assembly (I think it has bearings in it already too), gear case from a Merc 500 (Same part number as the Merc 350 case), carrier lock nut thing, seals, and the correct updated thrust washers. I think I have everything needed for the swap. Again I got lucky and found the gear case on Ebay for $90 shipped and in really good shape.

So I'm curious, how hard a job is this? I've never had a lower unit apart before, but I am mechanically inclined and work on cars and other small air cooled engines sometimes. I know I'm gonna need a service manual, but I'm just wondering if this is a job better left to a boat mechanic or if it's worth doing it myself. How much would a typical shop charge for swapping my parts into the new case? I have all the major parts of course, so I'm guessing it's mostly going to be labor charges and a few small odds and ends I may be missing.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Sorry to hear your problem. However, if you know how to crank a wrench, you should be able to do the job yourself without much issue. I wold absolutely buy the original factory shop manual for your particular engine. It will have everything you could possible want to know about the foot section. And then simply replace the parts and happy boating again. Of course you need to refill with the proper foot oil, but that is a general maintenance issue anyway. :thumb:
 

Strychn9ne

Seaman Apprentice
Joined
Aug 27, 2016
Messages
34
Yea it definitely sucks hard! I ran it in gear the other day for a few minutes on the trailer just with the proper thrust washers and another used prop, and it seems to be OK. Oil still looks clean and it's not making any odd noises, just that lower unit looks beat up and that bearing carrier will likely let water in now if used for extended periods. I'm gonna put it in the lake tomorrow for a bit and pull it out on my step dad's boat lift for a look.

Good to know! I can definitely turn a wrench :). Yea the exploded views make it look a little intimidating, but I think I can get through it. As with all things mechanical, patience is a virtue!

So far the only manual I can find is a generalized one that lists 2-40 HP from 1965 to 1989 or something like that, which seems a little too broad stroked for my liking. Kinda reminds me of those Haynes manuals for cars, 1989-1994 Chrysler New Yorker, Imperial, and Dodge Dynasty all in one book. Is there anywhere that I can get a shop manual for this engine? I have one like you mention for my '64 Ford Galaxie I got from Dearborn Classics, an exact reprint of the 1964 Ford dealer service manual for that model only, and that thing is worth every cent I paid for it!
 

BLKBEARD

Cadet
Joined
Sep 4, 2016
Messages
14
used mercury shop manuals are usually available on ebay. I never buy generic manuals
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Yea it definitely sucks hard! I ran it in gear the other day for a few minutes on the trailer just with the proper thrust washers and another used prop, and it seems to be OK. Oil still looks clean and it's not making any odd noises, just that lower unit looks beat up and that bearing carrier will likely let water in now if used for extended periods. I'm gonna put it in the lake tomorrow for a bit and pull it out on my step dad's boat lift for a look.

Good to know! I can definitely turn a wrench :). Yea the exploded views make it look a little intimidating, but I think I can get through it. As with all things mechanical, patience is a virtue!

So far the only manual I can find is a generalized one that lists 2-40 HP from 1965 to 1989 or something like that, which seems a little too broad stroked for my liking. Kinda reminds me of those Haynes manuals for cars, 1989-1994 Chrysler New Yorker, Imperial, and Dodge Dynasty all in one book. Is there anywhere that I can get a shop manual for this engine? I have one like you mention for my '64 Ford Galaxie I got from Dearborn Classics, an exact reprint of the 1964 Ford dealer service manual for that model only, and that thing is worth every cent I paid for it!

You can see an exploded view on boats dot net for your engine. Just type in your engine model and serial number and take a look. While exploded views look intimidating, in reality they are not. I mean think about something you know how to disassemble and think how many little bitty parts are on the unit. The exploded view would look intimidating for that as well. So just jump in and get er done.
 

Strychn9ne

Seaman Apprentice
Joined
Aug 27, 2016
Messages
34
Thanks for the tips and help here guys! I think I got all I need to get it all done. I got the housing, bearing carrier, some spacers/washers, impeller, and various seals and nuts. Also got an old bronze prop that looks virtually unused, but needs a good cleaning. Now if I can only find a wraparound cowling that's in good shape for the motor and get some fresh pain on everything, it will look all new again! Might be awhile until it's done, but I do plan on posting some pics of it all finished up. It'll make a nice cold weather project I think.
 
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