installing a limit switch in the power tilt?

4str · 12 May 2013, 03:09

So my 12 year old Yamaha 150 two stroke was stolen and I have re-powered with a Yamaha 150 4 stroke. So far I like the engine a lot, its a lot quieter and makes the boat go better. I almost feel like thanking the thieving scum.

The boat is configured with an engine pod past the transom. I have a dive ladder that gets stored on the outboard side of the transom. The old motor would contact the ladder at the extreme up position and the cowling was the worse for wear because first I, and then friends would raise the motor without looking back and run it into the ladder. Most of us would do it just once, but I have one friend that made a habit out of it.

The new motor's cowling geometry makes the problem even worse. At some point in a moment of inattention either I or a friend will raise the motor into the ladder (and now the transom if the ladder isn't there).

It occurred to me that a normally closed limit switch could be mounted on the engine bracket so that it would cut power to the engine tilt before it contacts the dive ladder or the transom. It would have to be a pretty hardy, environmentally sealed switch since it would live bathed in salt water.

Anyone run into this situation and come up with a solution? My new cowling is all shiny and blemish free, for now.

spartacus · 12 May 2013, 08:35

Move the ladder?

Maybe not as daft as it sounds. There are dive/bathing ladders that can be deployed over the side of the tubes, rather than bolted to the transom. Agreed the transom one is going to be the best option, but I can see this ending with a scratched cowl if you don't pay attention, which is highly likely according to 'sods law!'

Can the existing Yamaha trim sender switch be modified in any way?

Boats&Outboards · 12 May 2013, 08:38

Suzuki have this feature installed, not sure why the others haven't followed suit yet.

Peter @ Boatsandoutboards4sale ~ www.BoatsandOutboards4Sale.co.uk ~ 07930 421007

Nos4r2 · 12 May 2013, 09:44

If I remember correctly, Mercury used to use a trim limit switch on their first PTT system-the type with 2 independent rams bolted to the outside of the saddle.

It might be possible to retrofit one?

solent spence · 12 May 2013, 09:51

Quote:

Originally Posted by Nos4r2

If I remember correctly, Mercury used to use a trim limit switch on their first PTT system-the type with 2 independent rams bolted to the outside of the saddle.

It might be possible to retrofit one?

Is this why my 75 opti (with one ram) trims all the way up at the same speed, whereas an older 175 clamshell merc trimmed slowly, then went into a quicker tilt mode, which was a good feature?

Nos4r2 · 12 May 2013, 10:17

Not sure, but the switch I'm talking about is from circa 1979.

Bet your clamshell was 3 rams.

leemarlow · 12 May 2013, 11:09

How old is your yamaha 150hp four stroke

You can buy a tilt limit fit from yamaha which can be fitted to outboards

Pm me your serial number and I can look on the yamaha parts system to see your engine has the connector

4str · 13 May 2013, 01:40

Quote:

Originally Posted by leemarlow

How old is your yamaha 150hp four stroke

You can buy a tilt limit fit from yamaha which can be fitted to outboards

Pm me your serial number and I can look on the yamaha parts system to see your engine has the connector

Thanks! This is a new Yami, and if this exists I'll be ecstatic. The mechanic at the dealership I bought it from has a query into Yamaha but he has not heard anything back. He did say that the larger engines had this capability but not mine.

Thanks again.

leemarlow · 13 May 2013, 09:00

Just checked parts listing yes one can be fitted.

Pm sent

9D280 · 13 May 2013, 09:54

Quote:

Originally Posted by Nos4r2

If I remember correctly, Mercury used to use a trim limit switch on their first PTT system-the type with 2 independent rams bolted to the outside of the saddle.

It might be possible to retrofit one?

Loos like problem already solved, but yes, when I was looking at retro-fitting PT to my clamshell I did look at a modified version of that external ram gubbinry. (With some bespoke hydralic plumbing to put the hydraulic unit under the seat for neatness)

Yes, it had a limit switch, as the rams were "simple". The idea was that to Tilt (for towing / beach landing etc) you had to override the stop with a button. Theory was that if it trinmmed too far up, the swivel would clear the clamps and the entire engine would be simply supported by the tilt tube, one turn and the casting would break due to the levarage.

The modern rams have a "bypass" duct at an appropriate place with a low(er) pressure dump valve so the cyl can't hold the prop thrust and it will only tilt beyond there when the engine isn't pushing it back down.

4str · 13 May 2013, 14:32

Quote:

Originally Posted by leemarlow

Just checked parts listing yes one can be fitted.

Pm sent

Thanks for that. If you were not half way around the world you would be my new boat maintenance shop.

I think I am going to embarrass my current shop this morning. They did not know about this, they are a Yamaha dealer and they service a lot of boats.

4str · 24 May 2013, 03:26

A followup.

I installed the switch today and it works perfectly. It looks like it is built for its environment, it is a sealed switch that senses a magnet to cut power to the tilt. The instal was pretty easy.

I only wish it was installed last Saturday - doh!

Thanks again.

Turbodiesel · 25 May 2013, 21:22

Mercury have built in trim limits on the Verado and some opti's you just set the trim limit up through the laptop. Merc also do a trim limit switch that you can retro fit but its pretty crap, it uses a mercury tilt switch and its not very accurate!

martini · 25 May 2013, 23:18

My optimax's came with a plastic tube that clips onto the tilt ram inside the cylinder to limit tilt up.

Took me a while to work out why I couldn't tilt them up all the way!