Honda BF15A cooling problems

Hello, hoping someone has an idea or two. I purchased a 1990 15hp honda that looked in good condition, ran in the tub OK & the Mechanic that had carried out the last 2 services confirmed no problems, good motor, however on it's first run the telltale water outlet stopped running after about 5 minutes, luckily I had some whipper snipper cord in my tool box & I was able to give it a poke up the outlet whereby asmall crystal of salt came out & away the telltale ran again. This has happened on two more occasions & is worrying me somewhat. Another outboard mechanic suggested I blow compressed air back up the inlet but I feel this will just remedy the situation until any more salt makes it's way back down to block the telltale. I purchase some "Salt Away" & have run this through the motor hoping as the ad says, it will disolve the salt & flush it out at it's next running. Does anyone have any feedback on salt away or any other remedies, I would be glad to hear them. Thanks from Queensland Australia.

I just had the same problem with my Honda 9.9 (broken sea shells had gotten sucked up into the cooling ports)

I dropped the lower unit, replaced the impeller, and while the motor was hanging vertically off the transom with the lower unit removed, I sprayed water from a hose into the tell-tale hole -- whatever remained in the cooling ports came out of the water port pipe.

If you don't want to remove the lower unit, you could also pull the thermostat and flush directly into the cooling port (if it's just "salt" that's in there)

I put quotation marks around "salt" because it's also known as oxidized aluminum... the perils of saltwater use

BTW, if you pull the T-stat to flush it, make sure you replace the O ring on the T-stat cover

Thanks Marketic for the response, that sounds like the next evolution to take if the Salt Away doesn't do what it claims, will keep you posted.