9.9 yamaha water cooling problems

[Benday]

Several times my piser tube has gotten stopped up and the engine appears to be heating up, missing etc. As it is mounted way out on the stern of my sailboat and hard to get to to service, I cut her off before it gets seriously hot. When I take the cowl off and go to the tube and remove it from the pitot on the head it is wet and after clearing the tube it pumps well and the engine does not run hot or miss anymore. My question: is the piser the only place that water comes out of the engine (can't be) and 2. is it possible that the other water exhaust is clogged or blocked. As I only run the engine at a slow rpm and not a lot, but when I need it I want it there working.<br />Thanks,<br />Ben

 

[Feral Cat]

Re: 9.9 yamaha water cooling problems

If it is a 9.9 4 stroke, most of the water exits through the prop, along with the exhaust. I have two 9.9's on my boat, and they become clogged with salt. Fresh water flushing helps, and pulling the thermostats( very easily done) will give you an idea of how clogged they are. A product called SaltAway may help, have also heard that flushing with a fabric sofener is just as good and a lot cheaper.

 

[coolblue1152]

Re: 9.9 yamaha water cooling problems

I don't think those little motors have overheat alarms. I you sure it's getting too hot. You need to know the temp. You can tell to some degree by touching it. If it is getting hot enough to miss you better not do that again it will distroy itself. The pisser hole on my last engine glogged offten. I would just run a small wire in it to clean it. This is only for indication of water flow. It has very little to do with cooling the engine. So find out if you are really over heating. Buy a manual. Follow the procedure for the termostat checks. I bought a engine that was 90% blocked with salt and corrosion. You need more info.