Flushing out old power trim fluid

[AK115V4-93]

Hey guys,

I recently purchased a Yamaha 1993 115HP 2 stroke V4 outboard model 115BET (6E5). I am currently doing a service to it. I am looking to flush and change the fluid for the power trim system.

Currently the trim works perfectly but I have no idea how old the fluid is so I have purchased a Yamaha hand pump and bottle of the Yamalube Performance Power Tilt and Trim Fluid.

I understand that I have to make sure the fluid level is up to the filler port on the reservoir but how would you recommend removing all of the old fluid from the system? I want to make sure the fluid is completely new inside all areas of the system.

[RayBersch]

If you really want to do that you could reverse the pump procedure by inserting the pick up end into the reservoir and pump the fluid out. You may need to add a short flexible tube to the pickup end so you can reach the reservoir and manipulate the pump. Catch the fluid in a can or jar. To get it all out you may have to manually move the motor up and down.

But frankly, if it ain't broke don't fix it. Changing the trim fluid is not a regular maintenance item. You have several other regular maintenance items to tend to and taking the time to do them will pay off in spades.

[99yam40]

from what I understand the only way to remove all of the fluid is to take it apart.
the unit is not designed to do what you are trying to do.
as it is put together you fill up the different parts and then fill the tank and bleed the rest of the air out

[AK115V4-93]

Thanks for the replies. I ended up doing the job today. Took quite a while actually; eating up a number of hours and 3 bottles of new fluid. I wanted to make sure all the correct fluids are in the right places and are fresh.

As RayBersch suggested, I ended up getting an oil syringe with a small clear tube attached and slowly sucking out and then replacing what was in the trim fluid reservoir with new fluid. I think the last owner used ATF as the oil was red, but it was in good condition.

I replaced it with Yamalube Performance Power Tilt and Trim Fluid which is of a straw colour so it was easy to see the progress of the flush. After each refill I cycled the system 4 times then used the manual release valve a few times which sounded like it bled off any trapped air. After the final flush I ended up running the trim a few more times and adding extra fluid so it remained full.

So far all appears well. It was tedious to slowly flush out the old red fluid, but I feel it’s far better than opening lines and risking damage. I also replaced the o-ring on the filler plug to ensure no water gets into the system.

[RayBersch]

You're a better man than I, Gunga Din. I am sure you feel better about the whole thing which is a good enough reason to undertake such a task. By the way, ATF Dexron II (which is red) is the recommended fluid for my 2011 F150, but I use the Yamaha branded stuff like you.

I hope you enjoy your new toy - I sure like mine.

[AK115V4-93]

Yep, it was a very slow job to do thoroughly. I also ended up doing the gear case oil so I now know all fluids on the outboard are brand new and are of the correct type.
I want to look after my trim unit as I had a 135HP Johnson previously that had a faulty tilt unit and lifting that thing was a nightmare.

I’ll give the Yamaha a test run on muffs at the end of the week. Quite frankly I am looking forward to Yamaha reliability.