Tilt/Trim Indicator

badrano

Petty Officer 1st Class
Joined
Aug 7, 2018
Messages
331
What angle should the stern drive be at when the trim indicator indicates UP? I remember reading some posts about a 21 inch measurement on the trim pistons for setting the limit switch.
 

TunaFish389

Petty Officer 2nd Class
Joined
Apr 26, 2018
Messages
184
The trim limit switch and trim sender are two different things, while related, they have two different senders. The limit switch only job is to stop the trim so it doesn't go too high under way that could cause damage, the 21" referenced.

The trim sender should be calibrate to full down with guage just at bottom.. No matter what guage says you should trim to best planning speed.
 

badrano

Petty Officer 1st Class
Joined
Aug 7, 2018
Messages
331
The trim limit switch and trim sender are two different things, while related, they have two different senders. The limit switch only job is to stop the trim so it doesn't go too high under way that could cause damage, the 21" referenced.

The trim sender should be calibrate to full down with guage just at bottom.. No matter what guage says you should trim to best planning speed.

Ah, ok. Thanks. I know the trim limit switch works. Just wasn't sure about the trim gauge and what is should read when you hit the limit. For me it's about half up on the gauge.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,033
On an older outboard, the trim limit switch, in theory, is set when the midsection is about to clear the transom bracket. When that happens, the midsection would not have side-to-side support.

In practice, newer OBs have 2 trim cylinders, and 1 tilt cylinder. When the trim cylinders are at their max, trim limit is reached.

Actually, most props would ventilate before side-to-side support is lost, negating the need for a trim limit switch, or trim cylinder limits. When you ventilate the prop, you slow down noticeably, so it is time to trim in.

On Mercruisers, although they have trim limit switches, IMO, trim should be set by operator. This is best done by ear, feel and speedometer. Trim her until the wheel steers easily, the RPM and speed are max.
 
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