Advice on proper Trim position

[KathyD19]

Finally have had the opportunity to take my boat out on the lake a few times since restoring it and now that I know how to tilt up the motor (manually, not powered), I need to know what the proper trim setting is for this. The motor is a 1956 Johnson Javelin 30 hp and the boat is a 14 foot aluminum Rich Line from 1965. The motor was not original to this boat obviously, and when I purchased it it was attached to a 1964 fiberglass boat (not sure what kind of boat that is though). The trim position is how it's pictured here, with it in the notch closest to the transom. The first time I took the boat out with that position, it seemed just fine. But my brother, who remembers using the 14 foot alum. boat I was restoring for our family, took a look at it and said I need to move the trim out one or two notches because it's sitting straight up and down and it would be better at a bit of a slant. I moved it one notch out today and took it out on the lake, didn't really notice any difference. I have been the only person on the boat so far but have future plans to have 2 more adults with me soon. Will the increased weight load make me need to change the trim notch position? I really don't know what difference it makes, I guess that's what I'm admitting to.
By the way, I took my GPS along to check my top speed at WOT and it was 32 mph...is that pretty good? Sure seemed like I was flying! LOL. Thanks!

 

[Daviet]

Re: Advice on proper Trim position

Normally the cavation plate should be paralallel to the bottom of the boat. If the bow is plowing a little, move the trim out a notch and it will bring the bow up a little. It would depend on how the weight is distributed in the boat. I always liked the bow up a little so the boat would not plow water, but to each their own.

 

[Chris1956]

Re: Advice on proper Trim position

Normally the second tiltpin hole from the transon is the "normal" one. The others are used for transoms that are unusually slanted. Start with that one, and take some measurements of speed. Now move tilt pin up one hole and repeat measurements.

 

[kfa4303]

Re: Advice on proper Trim position

+1. The 2nd, or 3rd pin positions generally work best on most boats, but you'll just have to do some trial and error with what you think a "typical" load will consist of. OMC motors of this era had sort of an odd leg length of about 18" which makes them a little longer than most standard/short shaft motors which are generally about 15", but shorter than most "long shaft" motors which are about 20". As a result, they do tend to drag a bit. Daviet is correct when he says that you want the anti-vent plate, found just above the prop, to be level, or slightly higher than the keel (bottom of the boat). My '66 20 hp has the same size and I actually made a transom riser to get the motor to the right height, but that may be overkill. At any rate, 32 mph is pretty darn good. Getting proper (better) trim and tilt may not make you any faster on the top end, but you should notice better handling, improved ability to get and stay on plane at lower speeds and better gas mileage. Here are some pics of my set up, but I mostly did it to get a shallower draft because I do so much boating/fishing in skinny water (<12").