Engine Flushing

[gtreanto]

I have twin F115TXRDs and when I use the internal flush adapter on the port side engine water never comes out of the small water indicator that is on the rear right below the motor cover. When I flush with ears and run the engine it comes out. Anything to worry about? The starboard side engine works as expected.

[guitarzan413]

Probably plugged with salt or debris. I use a string trimmer line and run it up the tattletale hole to clear it out. I don't know if Yamaha has same problem as Honda, but I have come across an outboard where salt had completely plugged fresh water flush port. If you are in salt water, use the ear muffs and RUN your engine to flush, and use a salt terminator, otherwise thermostats are not opening and engine is not getting completely flushed and that can lead to costly repairs. Hope that helps!

[gtreanto]

Thanks.. But it is strange that it works when the

engine runs but not when I use the flush port. Or is this a normal clogged port indication on Yamaha's?

[guitarzan413]

Not sure with the yamaha outboard, but again that is a fresh water flush port, it won't help you in salt water, use the earmuffs and a salt terminator if you run in salt water. I have had to do quite a few muratic acid flushes because folks aren't flushing the engines properly and it's not cheap or good on rubber seals, ect.

[cpostis]

First of all, some people think I go overboard on maintenance.
Now I'm attaching pics and a link to a video of my SX150TXRZ (2001 OX66 2 stroke). Note the deposits within the cooling passages, although religiously flushed with the fresh water flush port, not muffs running, very excessive.
The video https://www.facebook.com/chuck.posti...type=2&theater shows what I do now to flush using a tank. The back pressure, when in a tank, I believe fills and the entire cooling path. Not so sure the entire cooling passages are flushed properly with muffs or fresh water flush port. After my first ever overheat problem,I found the cooling passages clogged with deposits, I did a complete tear down, cleaning, and reassembly. My exhaust plate has orifices that allow the block and heads to drain completely. These, and other orifices within the block and heads orifices were clogged either partially or completely. I had corrosion at the bottom of the block that I had filled and dressed before I reassembled. The motor now runs better than ever since I got it.
I guess I wouldn't pull heads to check for deposits, unless I did have an overheat problem. But, with a motor over 10 years old, maybe you would?

[gtreanto]

Thanks. Not sure if I want to rip things apart

yet. I'll try string trimmer line and see if that helps. I did order Salt-away and will start using it during flushes. Again things don't seem to be clogged. When the engine is in the water or using the muffs water comes out of the hole. Only when using the flush port does the water not come out of the indicator port. It would be nice to have a water coolant diagram.. Is there one for these engines?

[TownsendsFJR1300]

This came up recently with another engine.

Yes, it sounds like that end of the hose is clogged.

A great idea to try is to run the engine on muffs (or in the water) and remove /open the upper, Yamaha hose hook up. Basically back flushing water. You can poke line thru there to help remove it.

I don't remember the original Ops outcome but you can do this procedure W/O it being an issue.

Here's the F150 (from my shop manual), should be similar to this:
(it would also be in the Yamaha shop manual for your engine)

[drumbeater]

You're not trying to run the engines using that flush adapter are you? You are not supposed to do that. That is only for turning the hose on and flushing with hose pressure. You have to use muffs if you are going to run the engine. I'm pretty sure you can damage the water pump doing that if not other engine parts.

[fastback4]

You will need a water pump for sure