07 F225 overtemp alarm issue

[davepjr71]

Every once in a while my alarm comes on when I'm *****ing slow or have the boat in idle. If I shut the motor off and then turn back on the issue goes away. A friend thinks it's a faulty thermostat. Can anyone give me some advice?

[boats.net]

I would start with a new water pump, clean and check thermostats.

[davepjr71]

Probable cause of 2007 F225 overheat alarm

I finally got my boat out of the water and went to work replacing parts and trying to determine the cause of the overheat alarm. Since I just bought the boat I want to ensure all of the maintenance. Therefore, I boat new thermostats, poppet valve, and water pump/impeller kit.

I took out both thermostats and tested them. While they tested fine I replaced them and will use old ones as back-up in case of emergency. I took out both thermo switches and tested them. They tested fine. I took off the thermosensor and it tested fine. So, I dropped the lower unit down and took off the water pump housing and was like "Holy $hit, what is this?" Attached is what I found in the housing and probably the culprit for my low speed alarm. I can't figure out how someone could spend so much on a new outboard and have something like this in there? It looks like someone tried to repair it and then use a gasket maker to seal the metal housing to the pump housing. The owner may have never known this was done.

Looking down through the hole for the water tube. Can barely see the desk because of blockage.


Looking from the bottom. Look at the mess under there. It looks like someone tried to repair instead of replacing.

[boats.net]

The picture looks like housing is melted which means it run dry at some time.

[99yam40]

Looks to me like that thing got hot and melted the plastic housing, usually happens when motor is operated with out water available to water intake.
Either running motor with motor raised up out of water or with water hose attached to the flush fitting at power head and nothing at the water intake for the pump, or maybe just some debris covering intake while cruising.
Definitely needs replacing.

[davepjr71]

The unit is being replaced this week.

The impeller does have some rubber missing from it which was probably from dragging with no water. What's odd is the white glue like substance under the cap. Like someone tried to fix the problem by using rubber gasket to secure the cap down. Maybe the guy doing the maintenance messed up and instead of replacing the unit he tried to fix it? I also have to dremel off the metal colar over the plastic spacer to get the impeller off. From talking to people that should have slid right off.

Thank you for your input.

[coueytwo]

I have never had one of those collars come off easy, I have always had to cut them off, all my friends say how easy they come off, I guess the Yamaha Gods do not like me......

[davepjr71]

Yeah, I figured everything else was going to smoothly that there would have to be one part that would cost me more money than expected. Did you replace the wave and flat washers too when you did the change?

[99yam40]

I do not think it is necessary to replace them, just make sure they are all there and you install them in the proper order.
Read up on the procedure on installing the parts, make sure to lift up on the shaft to preload the shaft to keep it off the bottom. Otherwise it will make noise at idle from what I hear.

[davepjr71]

Thank you for the advice. I'll remember to do that.

[throrope]

I commend you for taking on that job.

IMHO, I'm much more confident on the water with my work than an unknown low buck orangutan employed by a shop with little integrity.

[davepjr71]

The dealership I bought the boat at said they did all the maintenance for the owner. Must not be a good shop. The key for the impeller was basically fused to the shaft. I had to cut the key off and groove out the opening for the new key with a drexel. Pain in the butt to do but now works great. Has anyone else had to do that?

[99yam40]

I have read that that happens some times, probably why it is a good idea to replace often like Yamaha says, that way it does not have time to seize up like that. Also R&R of the bolts may keep them from doing the same thing, they are a pain too if they break off.