Finally GPS'd the speed on the 75 MA

[McGillicuddy]

Originally Posted by povertysucks

I am running an '86 inline 115 merc with a 13.25x21" Laser II. Max im getting with a half tank and 2 people is 46@ 5800. Torque is unreal, with myself and about a 1/4 tank of gas it's 48. motor is mounted on the 2nd hold, and cruises right around 30-32 @ 4-4200 depending on load.

This is a very curious situation..
Normally I'd call bullshit but I know these motors can be wound up and spit fire. But 5800 rpm, ain't exactly wound up.
All sorts of questions but let start with this one:
What boat is this on?

[Fr. Frank]

Originally Posted by gofastsandman

Wimpy, wambly, wombly.

Endeavour to perservere.

And then we declare war, right?

[povertysucks]

its on a '72 20' cc. before I say anything else. I pulled it off a bass boat, and I have no idea if the guy before me jetted the carbs or not. I just know that I'm turning a 21" laser ii @ 58-5900 consistantly and getting 47 mph. I've only seen the 48 once, and it was with a slight chop, and a tail wind.

[McGillicuddy]

Roger that, povertysucks.
I would be interested in learning more. I was expecting you say it was on a bass boat, but I knew you had a 20 cc. Your numbers sound a lot closer to a 140 or 150 model. Can't help but wonder if the carbs weren't the only thing altered. 150 power head? 115 cowling, FL sleeper?

I have a healthy '83 115 and am pretty sure it won't even turn that prop. Heck, I'm running a easy to turn 15 p just to get 5600 rpm.

How high does your bow run and do you use trim tabs to level her out. I know the Laser II is a great speed prop but I'm very surprised you can spin any 21p on this hull with said motor at 2:1 gear ratio.

How high above the keel is your anti-cavitation plate?

Thanks for any insight you can offer.

[povertysucks]

Lol, florida sleeper, that's awesome. I dont think it is, the serial numbers say its a 115. I have no trim tabs on my boat, and it's about even with the keel. I might even be able to mount it one notch higher. I can tell you that offers a hell of alot of both bow, and stern lift. It shoots a nice tail when hooked up. I have some pictures of me doing so too. It hauls the mail for sure.

The first picture is before I swapped out the motor. the blue band was an '83, and I was getting identical #'s as McGillicudy

Second picture is me testing the 21' Laser ii with the '86 115.

Last picture is the motor I currently have. I am NOT running the Doelfin

[McGillicuddy]

Looking super light. And fast! Better get yourself together, er, I mean, better get yourself a tether... Still got me wonderin' where you're getting the extra 10 mph...

Awesome.

[Fr. Frank]

Can you post a couple of pictures of the carburetor setup you have on that 115?
I'd be interested in seeing if the carbs are WMK 14's off a 140/150 I6 Merc. It may well be that you've got the 140 powerhead "Florida Sleeper". I've done that trick twice.

I used to run an '83 140 powerhead on an '81 115 mid-section. I used all the externals from the 115, as it was on the back of a 15' Cacci Craft copy of the V-Mate, and the boat was labeled "Max HP: 115".

I could just touch 85 mph with a 2-blade 32" pitch over-hub solid brass prop at about 6300 rpms. I'll never forget the day it threw the #2 rod out the front of the motor and right through the center of the dash. I think it was several minutes before I really comprehended what had almost happened.

[Beaver]

You guys are getting me excited about these old Mercs. If my 90 ever takes a dump I might have to find me one of those.

Fr. Frank that is a gnarly story about throwing a rod. Someone was looking out for you that day.

[RUSTYNTABATHA]

they are out there and there are still some people around that know the tricks to tweak them... my dad ran 136 in the straits and 90 in the turns wuth a 140 massaged on a sst 140 back in the 80's....