The first one is the only way you are actually going to get fresh
water up into the top of the block more than once.
If you want, I can scan the water flow diagram from the shop manual.
The thermostat stops water before it exits the block (that is how it
works).
If the thermostat is closed, you are not going to get circulation
through those passages.
The second suggestion is a maintenance flush
You might want to do that on a 100 hour if that is once a year. I
usually do it at around 300-400 which is once a year for me.
(any time I have the foot off)
Gee, I'll keep all this in mind in case I buy another Yamaha outboard.
Rinsing an ouboard
Threaded Mode
