300 OMC on an 18' Tahiti prop suggestions?

**lbhsbz** · 11-29-2015, 12:52 AM

I recently acquired this boat...regardless of the degree of overkill, where should I start? No prop came with it. Engine is set back about 18" with the jackplate, Bob's LWP and I can get the bullet about 1" above the keel. I have a stack of Merc props, but they won't fit and
I imagine this thing will need a 30 or bigger. The last 2' of the bottom has been made into a delta pad. There are sandbags under the deck. It was so cheap I couldn't not buy it. What prop should I look for? Does anyone have a prop that might work?

**STV_Keith** · 11-30-2015, 01:59 PM

18" set back with that heavy motor on that short boat? Wow. Does it float?

I'd imagine you'd want a stern lifter to push the bow down. I'd throw a Bravo 1 on there to start...something easy to find. 28-32 pitch.

**RUNWME** · 11-30-2015, 02:19 PM

Your small shaft mercury props will fit. Drill out about and inch of splines and slide it right on. Then they can be used on merc or omc lowers.

Just slide your finger into an omc prop and feel how much shorter the splines are than a merc.

I did one at the boat ramp with cordless drill, drillbit and can of wd to lubricate. A drill press wouldve made it much easier.

**99fxst99** · 11-30-2015, 04:26 PM

A one inch hole saw works just fine. Use a drill press and a friend.

**dnelson964** · 11-30-2015, 05:48 PM

I had one of those many. many years ago and if I recall not very strong bottom or transom. Be careful with the weight and power of the big monster 300 ...you might try a cleaver style also.

Any pics you can throw up for us ?

**lbhsbz** · 11-30-2015, 06:30 PM

A Tahiti would not have been my first choice to hang this engine on, but for $850, I simply couldn't pass it up. The hull started off as a Jet, and it would appear (based on the "FL" machined into the setback plate, and the embroidery in the seats) that the outboard conversion was done by Finish Line Boats in Van Nuys. The coast guard tag also says Finish Line Engineering, not Tahiti.

I don't know if it will float. I do know that when I sat my fat ass on top of the 2.4 Merc on my Bahner Tunnel, it brought the weight to about what this monster does, and it didn't sink...so I'm hopeful that the Tahiti won't either.

Someone has added knee braces from the transom to the stringer, everything is glassed and tied together with 3/8" aluminum plate and angle...so it might just hold together. I was thinking of getting rid of the sand bags and the getting rid of the setback plate all together, but there isn't enough transom to get the engine high enough without having the jack plate all the way up, which doesn't make me feel warm and fuzzy...maybe I'll just shorten the setback plate and change the sides to raise the mounting plate 4" or so..then it would work. The boat is ugly and will likely stay that way...so I have no objection to building bracing everywhere if I need to. Bill has a 28 pitch wheel with a OMC hub that we'll try first and see what happens.

Got it running yesterday with some squirts of gas down the carbs...the VRO pumps were pissing everywhere so those went in the trash. It has a Holley Red in the boat that I'll use, the oil system was already pulled out so it's been running premix. The thermostats are gone, and the parts diagrams make them look complicated...I could use some help on these. Gotta get the trim working, T-stats, replumb the fuel system, then steal the control cables out of the other boat or find some cheap ones to get this thing wet and see if this is worth sinking any money into.

**lbhsbz** · 11-30-2015, 06:33 PM

Originally Posted by RUNWME

Your small shaft mercury props will fit. Drill out about and inch of splines and slide it right on. Then they can be used on merc or omc lowers.

Just slide your finger into an omc prop and feel how much shorter the splines are than a merc.

I did one at the boat ramp with cordless drill, drillbit and can of wd to lubricate. A drill press wouldve made it much easier.

Originally Posted by 99fxst99

A one inch hole saw works just fine. Use a drill press and a friend.

I have a mill at home...I didn't know they were the same spline. Thanks.