Honda 15hp cooling seems clogged

[tomwassmer]

Hello! I have a early 90's Honda 15 hp 4-stroke. During the last run of the season, I ran into some mud and the tell-tale stopped. I have finally gotten the engine on the workbench and started with a routine impeller change. Everything was as expected. The impeller seemed to be in good shape, although I'll replace it anyway. The intake port on the lower unit was free and clear. No evidence of a clog yet. I proceeded to check out the thermostat housing area. The thermostat itself looked pretty bad so I'll be replacing that as well. I blew air into the intake pipe from the lower unit up toward the thermostat housing to track down any clog in that portion of the system. Air flowed freely. I then blew air into the thermostat housing, hoping to feel it come out the tell tale hole, indicating (at least in my mind) no clog in the post-thermostat portion of the system. Air would not flow at all. Is this as it should be, or have I made progress toward isolating a clog? If air should flow freely between the thermostat housing and the tell tale, does anyone have an idea what/where to check next or how to clear out the clog?
Thanks in advance!

 

[greg daigle]

Re: Honda 15hp cooling seems clogged

try salt termantor its sold at any marine store its a liquid that you put motor in a tank and run some st in it it will remove all salt deposits in enging let it run for twenty min.

 

[tomwassmer]

Re: Honda 15hp cooling seems clogged

Thanks Greg, but I think if it's clogged it would be from dried mud in this case. Do you know if compressed air should be able to flow from the thermostat housing to the tell tale?

 

[Sea Rider]

Re: Honda 15hp cooling seems clogged

Blow compressed air through peeing hole inwards or poke a plastic tie & wrap of same diam, W40, carb cleaner plastic cannula back and forth tell tale with engine on and check if clog frees itself. On many egines tell tale port is connected near outside of upper water tube exit area, it's just an indicator showing water pump is working, has nothing to do with thermo area.

Happy Boating