Is something wrong w my tilt?

[mommicked]

Ive noticed my motor, 03 F90, will tilt when in reverse, and anything more than a little throttle. I assumed this is to allow it to pop up if I hit something w the LU while under way. I try to carefully do it now as the engine will slam back down if I dont. This happens more now since I installed a 4 blade prop.

 

[Inducted]

Re: Is something wrong w my tilt?

The PT&T should hold steady. Something is probably leaking internally. Obsorber valve ?????? Leaking ball valve????

 

[mommicked]

Re: Is something wrong w my tilt?

Thanks, for the reply. I dont use reverse often at all and the boat does'nt weigh alot, as long as I gently reverse it, it's OK. The tilt functions fine otherwise and no external leaks. I'll look into it in the spring.

 

[robert graham]

Re: Is something wrong w my tilt?

Might check the fluid level and add some Dextron II automatic transmission fluid if it's low. The motor's not supposed to "slam back down" at all. Good Luck!

 

[mommicked]

Re: Is something wrong w my tilt?

Thanks again for the advice. I'll check and or bleed it as soon as I can.

 

[mommicked]

Re: Is something wrong w my tilt?

Thanks again, Ive only rarely had this happen, crowded ramps, panic stops or trying not to hit submerged logs or trees in deeper water at slow speeds. I've had it rise up,and let it back down slowly w the throttle also. I'll check and bleed the fluid as soon as I can. oooops double post

 

[pine island fred]

Re: Is something wrong w my tilt?

The motor should be locked down in reverse to prevent the leg from climbing out like it is. Is probably a function of the same relief valve that will open if you hit something going forward to allow the motor to kick up. Do not believe there is a mechanical reverse lock like I have seen on some I/O legs. Will check my book and get back to you. FRED

 

[pine island fred]

Re: Is something wrong w my tilt?

I do not like the YAMAHA manuals, very little troubleshooting. My book is for the F-115, yours should be similar. Underneath the pump motor there is an UP relief valve assy. looks like it consist of a spool, pin and spring. On the side of the pump housing is the DOWN relief valve assy. Looks like you do not have to remove the pump motor to get to it.
I have to assume they are normally actuated when the unit hits the up or down limit to prevent burning out the pump motor. ( that squeeling noise when it is full up or down ). In a position less than full down, the 2 trim cylinder rams are going to hold the leg in position to keep the motor trimmed. There should be nothing locking the leg down in case you hit something, let it kick up. In reverse, one or both of those valves has got to lock the leg in position so it does not climb out of the water. I am going to guess it is the UP relief valve. There is an outside chance that the O rings in the ram are leaking but I would think that the leg would slowly drop when it was tilted full up. I have never had reason to try it but think the motor will not go to full throttle in reverse, is a function of linkage. Would be a lot of power working on those small valves. Maybe someone else knows.
Hope that makes sense! Have had a few beers getting ready for a party tonight. regards FRED

 

[mommicked]

Re: Is something wrong w my tilt?

This motors tilt system has only one hydraullic piston, w valve and pump motor attached, no assist rams. The ram looks small to me for the heavy motor but holds it steady at wot w trim applied. I have a manual that appears to be for my engine, though some stuff is missing.

 

[99yam40]

Re: Is something wrong w my tilt?

I have often wished my C40 would kick up easier as I run up into shallow water often, mostly mud and sand, but it still stops to boat real fast when motor digs in and I know that is not good for the transom and motor.

I would think that if it is a one way valve with a weak spring, then it would not slam back down like that as it would seal back off and catch the motor as long as the fluid level is good. If there is air in there then I would think you would hear it as it tried pumping air.
If it stays in place as the trim it out and run, do you have to re-trim the motor after it raises up and slams back down or does it go back to where you have it?
Keep up posted on what you find.

 

[pine island fred]

Re: Is something wrong w my tilt?

A few years ago I briefly had an F-90, I made a mistake and assumed it would be similar to my 115. Mine has the tilt ram as well as 2 trim rams that the motor bracket sits on when the leg is lowered enough for the prop to be in the water. I went back to my factory manual and there is no troubleshooting of the system which has to work the same. Someone should come along and give us more info. I am curious on how it works. FRED

 

[mommicked]

Re: Is something wrong w my tilt?

Sorry if I created confusion here. It drops back down hard, If I kill the throttle or don't let it back down slowly, when its tilted itself up with the reverse thrust. It does not compress the ram to bottoming out. It still sounds like something is wrong w the system from what I'm hearing.

 

[99yam40]

Re: Is something wrong w my tilt?

I do not under stand,
If the ram piston is not moving the there is a problem with the connections as it is tied to the motor at both ends

 

[mommicked]

Re: Is something wrong w my tilt?

I meant the ram stops the motor at watever tilt it was at when it raised itself.