TOPIC: Mounting my Merc 50 long shaft

Getting ready to drill holes to secure the motor to the transom. It's a long shaft Merc going on a 21" transom. You see alot of members, especially G3 owners, raising their short shaft and long shaft outboards a few inches above the transom. I did the same on my G3 with a Johnson Formula E short shaft, and my '58 Dorsett El Dorado with a '58 Johnson Super Seahorse 35hp. This seems to help on the smaller shallower boats. I have a '65 Starcraft Bahama long transom with a '65 EV Starflite 75hp sitting right on the transom. This boat is all original so I didn't touch this.

Here's my question to anyone that is willing to put their 2 cents in. Would you raise your long shaft outboard a few inches higher on a long transom or hang straight on the transom. Knowing this, the motor will be going on a light boat, around 500 lbs, 33 1/2 depth forward and close to 6' beam, what would you do? Thanks in advance.

Eduardo

Hey Eduardo, good to hear from you again. I think the focus should be on where the cavitation plate is in relation to the bottom of the keel, as opposed to where the motor rests on the top of the transom. Many of the performance Merc guys run theirs at least 1" above the "even with the keel" line, but here's a link that may help explain the procedure better;
www.marinepartsman.com/installing-an-outboard-on-your-boat.html

Thanks MarkS for that link. I appreciate it. There is a lot of information there. My plan is to have the Merc mounted by this weekend. Thanks again.

Eduardo

Before drilling, test! Telling you to set the motor at X height, is like saying you need a size 8 shoe, without ever having seen your feet!

Clamp it down good so you don't lose the motor. Start flat on the transom, run it, turn it fast, turn it slow, see if it blows out. Try some different motor angles, too. Bring some paint sticks or cut-up wooden yard sticks to use as rev-sticks. If you have a GPS, bring that, too, to get your top speeds. If you have a tachometer, bring that, too, as it means nothing if the motor is lugging (too little RPM) or screaming it's guts out (too much RPM). You want the RPM to be peaking a little above 5500 RPM with that motor, with a light load. If you have extra props in different configurations, bring them, too! Change ONE thing at a time, drive it, note any improvements/detriments. Go up one rev stick at a time until you blow out the propeller upon accelleration, then go down a stick to give you a cushion if conditions change. Then you can drill your holes...

Keep in mind, set up is all about what you're using the boat for. If it's going to be a family truckster, loading kids, gear, tubes, etc., then you want the set up to reflect that. If it's going to be a lake bomber, just you going from point A to point B at wide open, then set up accordingly. In general, if you get the set up right for your purposes, it'll result in more efficient running, too!

Test, test, test! The worst part about testing is you have to spend an afternoon driving around at high speed!

Thanks Chinewalker. I will do that, test all options first before I drill the holes. I recall that this motor was only clamped when last used, on a '65 Lonestar Mystic. I'll update the results.

Eduardo