Yamaha F100 tilt/trim issue

[SeaDouble]

Hi all, Nice forum you have here. Thanks for all of the great info.

I have recently bought a boat with a '99 Yamaha F100, and I am having an issue with the tilt/trim working intermittently. Sometimes it works normally, but usually if I trim up or down it will work for a few seconds, then stop. I will then have to wait a while before it will move again. In the meantime, I push the up or down trim button and I hear a click, but no movement. Sometimes I can hold it down, hear the initial click, but no movement, then I keep it held down and it randomly will move after 5 seconds of holding down the button. Weird.

Is this a common issue with these? I read of another issue with the trim/tilt on this motor (not trimming down after trimming all the way up) which is solved by replacing two valves, but that problem sounds different than mine. Same fix maybe?

Thanks alot for any help.

 

[99yam40]

Re: Yamaha F100 tilt/trim issue

You need to check to see if the relay is getting voltage to the trim motor and then see if it is pulling the proper amount of amps.

Could be a problem with relay or motor itself

 

[SeaDouble]

Re: Yamaha F100 tilt/trim issue

Thanks. I'll check that. Appreciate the reply.

 

[pine island fred]

Re: Yamaha F100 tilt/trim issue

My trim unit is laying in the bed of my truck right now. Just replaced the motor for the problem you describe. Intermittent going down although the relay always ckicked. Also sometimes the motor would strain and would not go down.
This is what you face. Replace the motor. If it is one being held down with 4 bolts, YAMAHA is going to charge you $536 for a new motor p/n 64E-43880-01-00. SIERRA will charge you $169.13 plus shipping for the same motor P/N 18-6783. I am very disillusioned by YAMAHA right now so I am a bit biased. You are going to have to disconnect the ram at the top, plastic bushings so the pin slides out easy, in order to get to one of the mount bolts. May as well take out the bottom pin and lay the whole unit on a work bench. Here is why. 3 of the 4 mount bolts will snap. The one that does come out is a blind hole in the pump body, the other 3 are in holes that are drilled completely thru the pump body which is a good thing. The heads will twist off leaving you 3 studs. Take some vice grips and try to remove the remaining bolt shank.
OK, those broke off at the base of the pump which is a good thing. Now, do not waste your time trying to drill and easy out the remaining studs, you will only break off drill bits and easy outs. I took a 3/16 in.. drill and drilled thru the studs so I can remount the motor with nuts and bolts, which is the way it should have been mounted in the first place. I used 10x32 bolts 1 1/2 ins long with self locking nut. Now your job is done BUT!
While that unit is laying in front of you, take a big straight slot screw driver and try to turn the manual release that lets you raise the motor when the pump is bad. Cant turn it can you? That valve is metal not plastic so you are in luck. Try to find the widest straight slot bit you can so it will not walk out of the slot and put it in a small impact driver. Still will not turn? Take the bit and slap the screw with a hammer a few times, then use the impact drive again. Hopefully it will then unscrew about 2 revolutions. Better to do this now than when the boat is in the water.
A bit of ranting if I may. In the last 10 years I have occasionally put a wrench to OMC, MERCS and VOLVO out drives, all salt water. Never had a problem. Put a wrench on a YAMAHA and you can count on bolts breaking off. I am stuck with 2 of them, one still in the box. Is no doubt in my mind, I could open the new one up and start breaking bolts while it is still in the crate. regards FRED

 

[SeaDouble]

Re: Yamaha F100 tilt/trim issue

Thanks for the input. It sounds like we have the exact same issue, except the motor I need to buy is 67F-43880-00-00. I spoke with a shop today that tested my relay and motor and said that's the problem. Its $650-750 for the yamaha part depending on who you buy it from. $239 is the cheapest aftermarket I've found. I think I'm going to give the aftermarket a shot. Hopefully I don't have the same problem as you with the bolts.

 

[pine island fred]

Re: Yamaha F100 tilt/trim issue

Try SIERRA MARINE ON LINE PARTS CATALOG. My motor is an 05- F115. Aside from the paint, it looks like the same motor, probably is. The whole trim unit is built by SHOWA not YAMAHA. Would not surprise me if other mfgs. use the same supplier. If yours is a fresh water motor, you might get lucky. FRED