Tilt angle of outboard

[garethdeb]

Hi Folks
I just got my first speedboat, a little 14 foot Marina and I got a Mariner 40hp twin 2 stroke to go on the back.
The engine came of a similar boat but my question is, what angle should I set the engine at once it's on the transom? It's a manual tilt and there's about five or six positions to set it too. May sound like a daft question but I'm new to this powerboating lark! Before you ask though, Yes, I have done my RYA level 2 powerboat course so I've got a good idea on how to handle her in the water, just don't know how to set her up.
Many thanks and regards
Gareth
Portsmouth (UK)

 

[tashasdaddy]

Re: Tilt angle of outboard

it is really a trial and error thing. start with the second hole for the transom. the farther away from the transon, the bow will rise, closer to transon, the bow will lower. find the happy spot. also with different loads you may need to move the pin.

 

[Texasmark]

Re: Tilt angle of outboard

And............. if it is a tiller operated engine, you will probably find that you like to run it in the farthest out notch(es) because that is where you get the most speed. However, the boat may porpoise on you (bow...front...bounces up and down) so you either have to tuck it in a hole or two, which slows you down, or put your fuel tank and tackle box and anchor and stuff like that up front till it settles down.

If you have remote steering and controls, porpoising is usually not a problem.

Gotta add this. Was watching one of those www home video sites the other day and a guy had like a 12 ft semiV with what seemed like a 40 (plenty of hosses) on it with tiller steering. He either was just fooling around or needed a USCG boating course, but on punch out, the bow was up in the air like 45 degrees before he got it down....but when it finally got down, that boat was really flying.....course there was an awful lot of porpoising too. Needless to say, if a safety officer saw that he probably would have been cited for wreckless behavior.

My 2c,

Mark

 

[5150abf]

Re: Tilt angle of outboard

With a single trim position it will only be really good at one speed so you need to do some trial and error and find the position that is the best compromise.

One setting will work best for top speed but won't be that good at low speed, it takes some playing but you will find one place that works okay everywhere.

 

[kenmyfam]

Re: Tilt angle of outboard

Gareth, your name and your avatar tell me you are a Welshman living in Portsmouth ???
One thing I did not see mentioned above is that the height your motor is set to is critical as well. To much motor in the water = excessive drag and lower speed. Not enough motor in the water = potentially prop cavitation and not enough cooling water getting pumped to the power head.
Good luck with your boat. Enjoy it and welcome to iboats

 

[garethdeb]

Re: Tilt angle of outboard

I am indeed a Welshman stuck in Portsmouth! Nothing I'd love more than to be back home in God's country but Pompey is where the work is I'm afraid.
As for the depth of the engine, the outboard is going on exactly the same model and length of boat it came off, just a few years younger so I'm assuming it should be correct. I'm also going to leave the tilt angle as it was when I got it (about two slots up out of five) and go from there.
Thanks for all the help and advice guys.
Regards
Gareth