Where is the thermostat on a Honda 9.9

[jopakent]

I'm in the middle of a battle to restore water flow on my Honda 9.9. I've replaced the impeller because the flow was getting intermittent. Now I have nothing. Part of the problem now is that I've misplaced the tube that routes the outflow from the engine to the little nipple on the right side of the cowling. Also, I can't see where that tube would connect to the engine. I've been looking on the right side of the engine.

Last night I opened up the left side and I think I've found it. There is a small port just above what I think is the thermostat. It looks like it is partially obstructed with salt and there is corrosion all around. I've got the bolts sprayed with 'blaster solution' and hopefully I'll get what I think is the thermostat off tonight. (Even if it's not the thermostat, those bolts must be replaced before they completely rust out.)

Hopefully, once I get the thermostat off, I'll be able to force water through the engine. I have the tube that routes water up from the impeller removed (and its clear). So hopefully, I'll be able to find the blockage and clear it once I get the <thermostat??> off.

Any pix or tips welcome. I would send a pic of what I'm looking at but the attachment thingee seems to be hosed, or I don't have proper permissions.

 

[SteveMFG_Oxford]

Re: Where is the thermostat on a Honda 9.9

I had a Honda 9.9 (1994) I bought new. I discovered that the water exit hole (where the pisser tube connects) out of the engine block was rather small and dried salt crystals or small bits of sand could block it up. I kept a piece of .80 weedwacker line under the cowl in the event it blocked I could ream it out. I had to use it a few times too.

Try the same on yours. Don't rely on just checking the "pisser" tube to see if it's clear. Also, make sure the plastic fitting (black) that is the exit point for the water indicator is clear as well. I had that block with debris too on one or two occasions.

You can check your thermostat in a pan of water at 170 degrees or so. It should open all the way. DO NOT over heat it. If it gets too hot it could be damaged. Ask me how I know.

A bit of Never Seize or Aviation Forms A Gasket can help mitigate corrosion on threads. Just don't over tighten the bolts.

My Honda worked flawlessly for nearly 13 years when I sold it. It became just to much for me to carry around. I now have a Honda 20 permanently mounted on a runabout. I also had a Honda 45 on a big RIB. They are great engines. Take the time to get to know it and you'll love it. Be sure to winterize it properly if it required. It will go a long time.