Honda 40 4Stroke Cooling System

[chopperguy]

My 1998 Honda 40 4Stroke has intemittant flow from the tell-tale, but never overheats. When running at full rpm it will have a nice steady stream then all the sudden it drops to a trickle. I just replaced the water pump, but haven't gotten into the thermostat yet. The cooling jacket cover on the side of the block does show some slight corrosion seeping from the edges. I can't imagine there being a complete blockage because the flow is great at times, then sometimes trickles. I recently purchased this outboard so i don't know it's complete history. Any ideas?

 

[Sea Rider]

Re: Honda 40 4Stroke Cooling System

Blow compressed air through peeing hole or run wire upwards/downwards several times, or carb clean, W-40 squirts upward, let soak, run engine at full throttle, probably salt crusts still clogging slightly water passages.

Being that horse 13 years old, would take cylinder head off and clean well all water circuit/passages specially if has been runing on salt water and you don't know if previous owner has rinsed well engine after use. Change thermo, place new head & crankcase gaskets, slight decarbon if needed, new plugs, torque well and that's it...

Happy Boating