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View Full Version : Trim and Tilt...........What's the difference?



Reel Nauti
02-05-2008, 07:57 AM
Hi all

Reading the threads and comments about motor trimming to gain better boat ride/handling got me thinking. My 40hp 4stk Yammie is fitted with 'electric trim and tilt'. Sure, it tilts the motor up or down, but what is the trim? Underway at reasonable speed, the tilt will not lift the engine due I guess to the thrust.

Years ago I had trim tabs on a different boat and understand the differences there. But electric Trim and Tilt??? What gives???

Interested in hearing responses from my learned friends!

Thanks

Dave

BM
02-05-2008, 08:28 AM
Dave,

Trim and tilt are 2 different functions yet they are combined together.

A lot of smaller Yams only have "tilt" which is there to enable easy lifting of the engine when not running (or not under power).

Perhaps the easiest definition is to consider the range of movement of your engine from vertical (or thereabouts) out to somewhere approaching horizontal. From engine fuly down position you have perhaps 15 degrees of TRIM when fitted with power trim and tilt. The rest of the movement is TILT.

TRIM adjustments can be made under power to trim the bow of the boat. If you trimmed your engine out into the TILT range and then put the throttle down you will overload the TILT and the engine would force itself down to the outermost TRIM position and stop there.

Most power trim/tilt systems have a large central ram which is the TILT ram and then 2 shorter rams (1 either side). THese are the TRIM rams and are the rams that can handle the load of the engine under power and adjust the engines position.

Cheers

Reel Nauti
02-05-2008, 08:59 AM
Thanks BM that makes it clearer. My 40 Yam only has the one ram, hence it not being able to lift whilst underway I guess. So really, this engine only has tilt? Seems wrong then that they are advertised and sold as having 'trim and tilt'.

More to talk about over a beer/bourbonia!

Cheers

Dave

FNQCairns
02-05-2008, 09:16 AM
Dave only one ram? But sold with trim and tilt...you have 40 neddies thats not huge amount for hydraulics to overcome.
If you operate the hydraulics from full down to full up, does it seem like it is 2 speed? slow for the start them speeds up at a point.
Guessing but a very simple affair to design 2 different valving's into the one unit, the slower speed will denote where the unit is on the stronger valving and will in effect be your trim. If single speed you are stuffed it's tilt all the way.

cheers fnq

mitch92
02-05-2008, 09:35 AM
I've learnt TRIM to be level of adjustment when under pressure/power as in trimming bow up/down. TILT is actual up/down of the engine such as lifting motor out of water etc.

Reel Nauti
02-05-2008, 11:08 AM
Thanks FNQ..............single speed all the way. Will only lift up to a bit better than idling. Any speed above that and it's no go.

Mitch, that's the guts of my question. It would seem from what I have now learned, that trim and tilt are just terms for hydraulically lifting the leg of the engine up or down? Trim is actually tilt and vice versa if the hydraulics are equipped to do it under way to a certain angle as mentioned by BM by FNQ. Mine can't do that, so it's just plain old simple as 'tilt'. Should be advertised as such instead of this 'trim and tilt' propaganda to make the engine sound more elaborate than what it actually is.

Cheers and thanks

Dave

Hornet Rider
02-05-2008, 01:37 PM
Dave,

Here's a link I found very useful in understanding the difference between Trim & Tilt. http://www.marinews.com/boat_article_details.php?recordid=37

BM summarised it well. Just a question though, are you saying that when you purchased you motor/boat that the dealer, or the labeling, indicated that you had 'Trim & Tilt'? Or, are you just making the general point that Trim & Tilt functions can be misunderstood?

cheers

bar raider
02-05-2008, 02:01 PM
I've learnt TRIM to be level of adjustment when under pressure/power as in trimming bow up/down. TILT is actual up/down of the engine such as lifting motor out of water etc.


i agree mitch,
you can still call it trim and tilt if u have only "one ram" or only "one speed"

the term "trim" generally refers to the first 15 or 20 degrees of movement either side of vertical when driving at speed.

the term "tilt" is generally used when moving the outboard further up or out of the water to beach boat or for shallow water running.

so theoretically all hydraulic systems are "trim and tilt"


quote REEL NAUTI

hence it not being able to lift whilst underway I guess

why do you want to lift the motor at speed anyway?

Reel Nauti
02-05-2008, 03:12 PM
Hi BR

It's only a tiller steer job on a 4.4 tinnie, but sometimes underway and coming into a bit of a chop I like to lift the bow a little in an attempt to keep my wife from wearing a lot of water over the bow. I have to reduce speed to little more than idle to be able to do this. I was of the impression that a trim and tilt system was able to do this whilst underway.

HR, when I bought the engine 18months ago it was sold as having 'trim and tilt'. It also said the same on the Yamaha website. The only reference Yamaha make to just 'tilt' is for the external switch on the engine side.

Cheers

Dave

MyEscape
02-05-2008, 03:18 PM
Dave,

I have a 2008 2 stroke Yamaha tiller steer with trim and tilt. I can adjust the trim at any speed.

To be honest I haven't looked with there is 1 or 2 rams. I've only had it 4 weeks but when tilting motor on the trailer you can tell when it changes from trim to tilt.

Steve

MyEscape
02-05-2008, 03:20 PM
Ok Dave, just had a look, it's got 2 rams. Long and the short. Mine's also got the trim/tilt switch on the tiller as well as on the side on the motor.

Steve

bar raider
02-05-2008, 03:52 PM
is it really not trimming up (watched it) when underway or just not lifting the bow ??

ask the dealer if it should caus maybe there are hydraulic/pressure problems, just a thought.

Skusto
02-05-2008, 06:00 PM
oh old tinnie a tiller 30hp yamaha 2 stroke with trim and tilt sounds strange that your 40 fourstroke doesnt.

BM
02-05-2008, 06:04 PM
Dave, to confuse things slightly more, around 1980 Mercury developed a big arse single ram trim/tilt setup for their V6 engines. So this is a departure from the normal 3 ram system I mentioned before.

It was a one speed system but you could trim the engine right out under power (just in case you wanted to go vertical I suppose!!). Later they opted for th e3 ram system which is common across all brands these days.

When you slow to trim the engine out does it hold? or push its way back down?

Cheers

Kleyny
02-05-2008, 07:56 PM
I have an 05 model 60hp merc and its only has one ram that can trim at full speed to bring the nose up or down as required.

But something i have noticed with my system when i bring the motor down from out of the water after it gets to a certain point (close to the stern) it does like a click or a notch.
from what i can gather this is when it comes into the trim section of the ram.
I havent noticed a different speed after this though (but that doesnt mean its not there)

neil

haggis
02-05-2008, 08:05 PM
I have a yammie 4st 40 with trim & tilt & can trim & tilt the motor at any speed .
it is on a 410 runabout . never had any problems with the little yammie .
cheers haggis

Reel Nauti
02-05-2008, 09:29 PM
Mine will not lift the engine at all whilst underway if I am going any faster than a bit more than idle. Perhaps there is a problem. I've also noticed that when I first activate the ignition, prior to starting, that the oil and temp lights do not come on. As I said, this is a tiller job with everything on the stick. The engine is only just now due for it's 10 hr service. I bought it when we lived in Rockhampton and have no idea really what to do or who to go to down here. I'm at Petrie. Your advice is very, very welcome.

Thanks

Dave
Ps: This is the same engine I asked about in another thread about not kicking up if engaging terra firma. On one occasion I hit a sand bar, and we came to a shuddering halt within no time. The engine did not kick up even with that. Perhaps a problem with the hydraulics?

MyEscape
03-05-2008, 05:38 AM
I didn't think the motor wil kick up if you hit sand, only rocks. You will come to a halt though, but the process is a lot slower than hitting a rock, hence no kick up.

Steve

Kleyny
03-05-2008, 09:45 PM
Dave
Ps: This is the same engine I asked about in another thread about not kicking up if engaging terra firma. On one occasion I hit a sand bar, and we came to a shuddering halt within no time. The engine did not kick up even with that. Perhaps a problem with the hydraulics?

Mine comes to a shudering hault when i hit a bank as well:'(

neil