OMC Sterndrive Stringers Rotted At Motor Mounts

[boppa7]

I was attempting to remove the starter tonight and found that it was REALLY tight working down there. Then I noticed that the edge of the starter had begun rubbing against the side of the bilge wall. Hmmm...<br /><br />A little further back from the starter I could see that the stringers were rotten right under the motor mounts. The whole engine and sterndrive is about 1/2-3/4" lower than it should be at the back. When I stand back and look from the outside I can easily tell that the intermediate is not centered on the boot - at least an extra inch of boot is visible on top!<br /><br />So now I am wondering what to do... the boat is 25+ yrs old. Motor runs well. Sterndrive is in good shape. Hull of the boat is fine. I could probably unload it for few bucks but would kinda like to keep it as it has served me quite well.<br /><br />Is replacement of the stringers under the motor mounts a big deal? Does the engine, etc have to be removed or can it be lifted while the stringers are replaced below it? Any (even rough) idea how much a job like this will typically cost?<br /><br />Lots of thinking to do on this one ;-)<br /><br />Steve

 

[rodbolt]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

its easier to remove the motor but I have sistered the stringers with the engine supported and the mounts removed. you will need to cut out the section of rot and sister in a new piece. preferably fir or juniper laminated together with west system and lag bolted as well as epoxied back in. the stringers on that unit absorb the drive thrust so they need to be strong but its not hard just time consuming.

 

[Fuzzydog]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

might have something of value to add here...<br /><br />I bought my neighbors 17.5' bowrider with OMC sterndrive. He sold it to me cheap because the motor mounts were rotted and collapsed, much as described in this post. <br />The thing of it is, that it wasn't just the motor mount stringers, it was the motor mounts, floor stringers and transom. <br />It's not just a matter of replacing the motor mount stringers, but finding out why they got wet in the first place, and what else has rotted.<br />I would strongly advocate pulling the motor, cutting out at least the back 3rd of the floor and taking a good look at what's going on under there.<br /><br />good luck

 

[KaGee]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

You'll get a better response in the restoration forum.

 

[supercab78]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

If you can't do it youself you should sell it. I went through that about 15 years ago also with a 1975 OMC. I paid to have it fixed, cost about $1600 in 1989. I still have the same boat but so far I've been able to find parts and do my own outdrive repairs. The reason I would say sell is because if the outdrive give you trouble down the road and you have to pay to fix it you will have alot of money in the boat. You could try to crutch it some how instead of repairing it properly and use it till something else goes bad.

 

[Boomyal]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

Easy fix if you're handy. As for the starter, get a High torque gear reduction starter. You'll have plenty of clearance and the motor will crank better. <br /><br />

 

[boppa7]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

My decision is made... I will try to fix this myself.<br /><br />I like Fuzzydog's note of caution that the rot may be more extensive than I thought. I will probably tear up the floor and have a good look. If I find that the transom needs work am I in big trouble? The OMC Sterndrive is stringer mounted but I am still thinking that weak transom would be a problem, right?<br /><br />As for engine removal... any tips? Seems to me that lifting and moving a 305 V8 is gonna be more of a challenge than the teardown/rebuild. If I drop the engine on the garage floor then I won't care too much about the rotted stringers ;-)<br /><br />Thanks for all the replies,<br />Steve<br /><br />BTW: Is cross posting to the restoration forum good ettiquete (and how do you spell eddi-kit)

 

[OttawaAquaBoy]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

Hi Steve, et·i·quette<br /><br />Good luck with project, I'm sure if you pour enough beer into some friends they'll help you pull the engine. Drunk dudes are much softer than garage floors <br /><br />BTW a moderator may be able to move this to the restoration forum.

 

[KaGee]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

Look here: http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=013537

 

[boppa7]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

I like it... I like it a lot!<br /><br />When I'm done I will turn the wooden motor lifter structure into the garden swing my wife has been asking me to build. I get to keep the boat and score some points with my wife, all thanks to KaGee ;-)

 

[Boomyal]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

Originally posted by Steve Linkim:<br /> If I find that the transom needs work am I in big trouble? The OMC Sterndrive is stringer mounted but I am still thinking that weak transom would be a problem, right?

Your transom, is most likely not covered entirely by wood. You can see how mine is in the picture above. If it is rotten it would be a breeze to replace. The transom, on an OMC, carries no load related to the drive train. The wood that is there also has no structural value. It doesn't even carry any load from your stern eyes.<br /><br />Keep us posted on your progess. I can give you a lot of pointers along the way and give tips on how to keep the mount rot from occuring again.<br /><br /><br />Other ways to remove your motor are stout tree limbs, stout roof/ceiling beams, a forklift and possibly a tow truck. I do think KaGee's lift is sweet tho, especially if you can kill two birds with one stone.

 

[boppa7]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

Thanks for the tips Boomyal.<br /><br />I am leaving town for a few days and plan to begin tackling this in mid-sept. I will keep everyone posted and look forward to your pointers.

 

[Fuzzydog]

Re: OMC Sterndrive Stringers Rotted At Motor Mounts

Mine has a GM inline 4 and to remove the engine I backed it up between 2 trees, used sturdy ropes to lash a 6x6 beam between the trees and then a comealong to hoist the engine out.<br /><br />One thing I didn't think about (in case you don't either) - after you take the engine out.....the front of the trailer is going to be VERY heavy and will take some effort to lift on and off a hitch (unless you have a crank) Also if you haul it anywhere without the engine, the towing vehicle will really feel the weight