Tilt/trim motor intermittent

[Mustang65fbk]

You can either use an old turkey baster, or something like this on Amazon...

https://www.amazon.com/Standard-Bottles-Transfer-Transmission-Differential/dp/B0CSK43NVF/ref=asc_df_B0CSK43NVF/?tag=hyprod-20&linkCode=df0&hvadid=693747049168&hvpos=&hvnetw=g&hvrand=8541234370816113962&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1027654&hvtargid=pla-2297021507511&psc=1&mcid=17f9b5f42da43451b22d1e036b9ab98a

 

[Sardinia306Canyon]

I have to ask how in the hell do you fill the reservoir. The hole is only about 5/16.

First, when oil level is low, trim motor will still turn and you will hear that. If the trim motor is not turning then you should verify if current is arriving before and after the relais. If current is there, applying current directly to the plug is not working either and tapping the motor to unstuck the brushes does not work neither then you have to pull the trim motor and thats a pita.
I used a small plastic hose i attached to the ATF bottle what had a conic opening.
Otherwise a pump as shown in the tread before to fill the reservoir till it's overflowing, but then you need to trim up and down several times and refill to get rid of all the air in the system, and that require a working trim or you raise and lower manually.
Raise outboard to max, fill till overflowing, screw on cap and lower the engine to max, raise again and fill till overflowing.
Repeat till full

I used it the rest of the day like that. 40 miles and a couple of hours, got back to the dock and tried it, and all worked normally. A Yamaha mechanic I know said the motor is not really repairable, so if that is the problem, the motor assembly has to be replaced. I will check the voltage if it happens again.

A "self repairing" trim "motor" indicates either a cable or relais problem or the brushes sticking what got temporary solved by vibrations when boating. Intermittent problems are a pita to solve as they mostly happen when it's not possible to verify, at sea for example.
Check first cables and power before you do a expensive and unnecessary mistake with the trim motor and pulling it and verify well if the relais is clicking:
if relais clicks then problem is most likely between relais and trim motor and iwould guess the brushes worn
if relais does not not click then the relais is bad or the problem is before the relais, but this would mean that both switches (control and cowling) are bad what does not happen often.

Again, we repaired several trim motors on my and others boats by replacing the brushes, so they are partially repairable.
In this tread you will get informations and pix about a trim motor, the brushes and how to pull the trim motor.
https://www.thehulltruth.com/boating-forum/1341804-skowa-trim-tilt-leak-what-do-2.html

Chris

 

[seasick]

I use a plastic syringe to fill the reservoir but an easy option is to use a plastic squeezable condiment bottle like you would for mustard or ketchup