Question on proper trimming

[Jarhead44]

I bought a new 19" Smokercraft modified v hull last year with a 150 Merc Optimax. I went from a 16' Sylvan with a 60 hp deep V. I've noticed at low speeds if not on plane the stern really digs in bringing up the bow affecting visibility. Seems like my old boat cut thru the water with alot less effort. Any tricks out there?

 

[JB]

Re: Question on proper trimming

At speeds below plane you need to trim the engine all the way in. That will lift the stern as much as the boat CG will allow.

Once on plane, trim out to the maximum you can do without getting the boat to porpoise or the prop to ventilate.

 

[tashasdaddy]

Re: Question on proper trimming

if this does not solve your problem, consider Smart Tabs.

 

[backwater dawg]

Re: Question on proper trimming

Smart tabs or a correct sized set of manual tabs---I use Smart tabs on my jet boat and they work great--but I'm always on the gas--in my 28' I prefer the control manual tabs give--Steve

 

[Jarhead44]

Re: Question on proper trimming

Thanks for the info. i might look into prop options to.

 

[Jdeagro]

Re: Question on proper trimming

90% of the dealers will try to correct this problem with a prop. First suggestion will be to reduce the pitch. This will allow you to get on plane easier. It will also increase the RPM's at any speed and cost you more fuel. Not something I would want at $3.50 + per gallon.

However; you are trying to run at slower speeds and maintain visibility over the bow. A prop change will not do that. Trim tabs (any brand) extend the hull, and allow you to change the hull configuration (design) to provide more lift (stern) when needed and less when not needed. They do other things as well, but let's stay on point. In short, the hull is adjustable on demand.

Results? Minimal bow rise = no hole = no hole shot. Cruise slower and stay on plane. Run smoother at any speed. Improve handling. Improve fuel economy

 

[D445547]

Re: Question on proper trimming

Running at such a slow speed will also reduce fuel economy. Not to mention all the CO you will be dragging into the boat due to the station wagon effect...not good.

 

[Jdeagro]

Re: Question on proper trimming

You will find the most efficient speed (fuel econ) between 3000 RPMs and 3500RPMs on most boats. However, no matter what speed, if you keep the boat in proper trim (atitude) it will improve fuel economy.

 

[fishmen111]

Re: Question on proper trimming

Have you checked your trim limit cross-bar on the transom mounting bracket. It should be in the hole nearest the transom while still preventing contact between the boat and motor in the fully trimmed in position. If out too far, it would prevent you from trimming in enough to lower your bow. Even though it's a new boat, you might want to re-distribute some weight (mainly batteries).

 

[backwater dawg]

Re: Question on proper trimming

I don't think CO is an issue in a open boat under way--CO is heavier than air and settles into the lowest part of the boat at rest--with an engine or gen running--not under way--also tabs of any kind STOP the boat from dragging by acting like a airplane flap and providing lift so the boat is as level as possible and has LESS drag---welcome to iboats Sheriff

 

[rfdfirecaptain]

Re: Question on proper trimming

I don't think CO is an issue in a open boat under way--CO is heavier than air and settles into the lowest part of the boat at rest

You are incorrect. Carbon Monoxide (CO) has a vapor density of .97 as compared to the weight of Air which =1.00. Carbon monoxide is so close in weight to Air that it doesn't move much, unless several conditions are met. On very sunny, less humid days, it will rise although ever so slowly. On humid days, at nighttime around LAKES, and other waters it tends to become slightly heavier, bringing it's vapor density to a weight closer to that of Air, which would cause CO to stay buoyantly neutral or even sink slightly. Of course, wind is a factor anytime.

In addition please check out the link below and beware of what may lurk near the stern of your boat (CO) and read the documented cases of the deaths that have been associated with it. You can't see it, smell it, or taste it.

http://www.doubleangel.org/documents/NationalCaseListingBoatRelatedCOPoisoningsApr2007.pdf