Yamaha 4 Stroke 25hp Trim/tilt Problem

[dumbochickenhead]

Gidday to you all, only new so hope this doesn't give you all too much pain. I have searched and searched for info regarding overhaul/breakdown of trim/tilt motor.
I have a Quintrex Dory 4.2 Wide with a Yamaha F25ELHW 4 stroke, (checked web site and pdf but doesn't look similar to unit and further searching codes tell me it is electric start and manual tilt - eeehhhh!!!) and having some troubles with bow steering (hopefully just not trimmed properly- but still scares the crap out of you). I try to trim up and motor slowly falls back down, will do this for four or five goes, then seems to stay under pressure. Checked oil - clean and level OK. Little bit lost why pressurises after 1/2 dozen goes. Only a filler hole on side of unit. No other adjustments. Thanks in advance for ideas. Need to be able to go fishing each time without changing undies everytime someone moves in the boat. Thanks again

[Outsider1]

Hi DCH,

it would really make it a lot easier to diagnose your problem if you were able to post some pictures of your motor set up.

Have a look at this thread to see what I mean;

http://www.ausfish.com.au/vforum/sho...d.php?t=128448

How to post pictures is described here;

http://www.ausfish.com.au/vforum/sho...d.php?t=103565

Cheers

Dave

[Scott Ashe]

Hi Mate,

How old is you engine, if it's under warranty I'd take it back and let you dealer have a look. Could be something with the Ram. I have the same 2007 model engine, powering an Allycraft Rhino 4.10m.

Cheers
Scott

[Noelm]

being only a 25HP it may be possible that an after market trim setup has been used, also is the bar that stops the Motor going all the way in still in place? this can be set to prevent the trim from pulling the Motor too far in (it does not fix your problem of course) and as mentioned, is it still under Warranty? if so, then do not muck about with it, if not then the Hydraulic system is quite simple, but sometimes requires a few special tools to dismantle it.

[dumbochickenhead]

Thanks for your replies guys, I will post some photos later on tonight of the motor setup. I have only purchased this boat recently in the last two weeks. The boat is 1994 and the motor 1998. The trim/tilt is a single ram and the reservoir/motor is mounted on the rhs of the motor with pipes to the cylinder. There is no visible oil leaks anywhere and no loss of oil when checking level with the engine all the way up. There is a bolt fitted to the 3rd lower hole to restrict the trim in. If the motor was completely down (resting on the bolt), I could lift using trim button to about approx 2-3 inches and the motor would gradually go back down in a matter of 20secs approx , then I would lift motor again and the motor would stay in that position, it then has resistance trying to manually push it down, but doesn't seem to move.

[BM]

Assuming its a genuine trim setup and not aftermarket its quite probably with a low hp engine that you only have a tilt function. Yamaha did/do this with their smaller engines and the tilt is for ease of raising the engine but not designed for trimming the engine whilst underway.

Assuming you are interpreting the serial codes correctly then its sounds like a bit of a "fiddled with" engine.

Cheers

[Noelm]

yep, that is correct, some Engines did come with "trim" and not 'trim and tilt" always a possibility

[Noelm]

wooops that should read "tilt" and not "trim and tilt" geees I am silly sometimes.

[dumbochickenhead]

Okay, trying to upload photos, I accept may be tilt only; now to fix bow steering.

I have read lots of forums regarding heights etc of cav plates, so I understand the contraversy I am about to flooded with and accept all thoughts and appreciate all recommendations , but, after looking at my own photos, I even believe the motor should be raised, maybe, but then again that's is why I have my login name.
Thanks for who can help.004-m.jpg 006-m.jpg
As you can see, around 50mm below bottom, but seems easy still to cavitate if trimmed up a little.(Again, I dont think I should of been loading up the 'tilt' function - should of been resting on bolt as per following picture,012-m.jpg
The following pic has 50mm between hole centres but wont give much grab on inside clamps, do you think this would help by raising.015-m.jpg
Thanks again in advance!!!

[BM]

Been some mods going on there.

The bolt in place of the trim rod is not standard. Someone has obviously fitted a "tilt" system to the engine.

Is the cav plate level with the bottom of the keel extrusion? And in those pics is your engine at right angles to the line of the keel? It doesn't look like it.

Cheers

[dumbochickenhead]

Okay, I have some more info: the keel extension is 50mm deep and finishes about 550mm from the stern of the boat. The following pic has the motor fully down resting on the stop. Do you think it should stay were it is or ??????????
The main problem is I have one or two seated at the rear and one seated at the front. At full power it seems to bow down and is easy to turn if anyone moves to the side even slightly. Sometimes quite scary the boat leans quite badly to the side until all rebalance. Has the sensation it will get away from you. Thanks 001-m.jpg 003-m.jpg 005-m.jpg

[dumbochickenhead]

Any suggestions to make more stable please..