70BETO6H3 - Trim & Tilt Stuck, mangled release valve. Fix & engine ID help req'd

[New Owner Old Boat]

Hey all, I think have air locked the trim tilt on my newly acquired 2 stroke 70hp (70BET0 6H3 L), but the manual release valve has been mangled and has no head.

Question 1 - Is there another way of releasing the air lock if the valve is not operational? Opening the reservoir plug and filling with fluid Plus leaving overnight hasn't allowed it to drop.

Question 2 - Which way / ways should I try to remove the valve? The valve is on the right hand / starboard side, and the casting marks are: Counter clockwise = Power Tilt, Clockwise = Manual Tilt. Does this mean it is a left hand thread and I remove it by turning clockwise?

Question 3 - Engine Plate shows: 70BET0 6H3 L 455161 - Which doesn't appear on the BN parts page - Any ideas what year it is and therefore, what valve I need?

Thanks in advance

New Owner Old Boat

[DennisG01]

Does it not tilt properly? Or does the engine fall back down? How did you cause air to get into the system in the first place?

Air can be trapped throughout the system - not just in the reservoir. To get the air out of a tilt system, you have to (numerous/many times) run the tilt up and down. Each time it goes up, put it on the support stand and check/add fluid.

You're going to have to get creative with the manual release screw and maybe try to create a slot for a screwdriver with Dremel tool and an engraving bit. But it sounds like you're saying it's a bolt-head? Mine has a slot for a screwdriver.

It will be easier if you remove the tilt unit from the bracket.

Mine has a circlip to retain the bolt - does yours have that?

[boscoe99]

A 70BETO was not distributed within the US. That is why you won't find that model in any Yamaha USA parts books.

Seems to be a 1985 model year motor. Should be similar to a US 70ETLK model. https://www.boats.net/catalog/yamaha...ar/1985/70etlk

[New Owner Old Boat]

Thanks Boscoe - I'm in New Zealand but whatever internet searches I did it always led me back to the BN catalogues to work out part no's.

Dennis - It is a newly acquired old boat & motor and the trim tilt was sort of working - before I tried to fix it!

I pulled what was there of the boat apart to put a new transom on, and was in the process of putting it all together again including adding: floor, seats, controls, everything else etc etc. when I inadvertently stopped the trim / tilt from working.

Trim / tilt was mostly working (noisy and a bit hit and miss on speed though) before I pulled everything apart - directly after I put the engine on the transom, I did manage to briefly get it going up and down after rewiring the control unit - I then tilted it up so I could get to the reservoir filler - Hey presto, motor now stuck in up position.

1. I don't actually know that it is an airlock - I just don't know what else would give me the symptoms I have. N.B I was able to add approx 100ml (3.4 ounce?) of fluid to the reservoir
2. I think mine was a slotted screw style head but one side of it is sheared off. the remaining side is also pretty wrecked.
3. The hole to reach it through the bracket is pretty small (approx 3/8 - 1/2 inch diameter I guess) and I am struggling to see if there is a circlip there or not.
4. The transom casting shows turn clockwise to switch it to manual trim / tilt - does that mean that the whole valve will unscrew that way too?
5. If so and my brain is working correctly, can I drill and tap a standard bolt into the valve that will unscrew the valve as the bolt is tightened?

[DennisG01]

It seems strange that you turn it CCW to open the manual release system. Mine is the "normal" way. But, whichever way turns the screw to make it move stbd is the correct. I think there has to be a circlip in the there to stop it. I think it would be a royal pain to try and drill/tap - it should be MUCH easier to just remove the assembly. I was able to remove the entire assembly from the bracket on my 250HP without even lifting the engine off the transom - even though everything I read online said it wasn't possible. It took me all of about 30 minutes, max. It will be much easier to work on this on your workbench. Once you create a new/better slot, you can use a hammer screwdriver.

If the engine isn't physically moving, but the tilt motor is making noises, the problem is in the plumbing (either a passageway is clogged/bad o-ring/fluid level). If there is NO noise, then the issue is electrical.

[New Owner Old Boat]

Cheers Dennis

To the "how to" trim / tilt removal pages I go then.

Some pretty pics for anyone interested.

IMG_4512.jpg
IMG_4513.jpg

[DennisG01]

If it's like mine, it really is pretty straight forward. You can eyeball things by looking at the assembly to see if it will slide out aft. There's really not a whole lot holding it on and it's easy enough to figure out just by looking at it. The electrical is straight forward, too. PB Blaster, a couple times a day for a few days prior, won't hurt, either. Same for the release screw - PB Blaster, 30% Vinegar, muriatic acid, etc. Anything you can do to loosen up old salt. Looking at your pics, though, it doesn't look that bad.