We are the new owners of an old Tohatsu 5hp 2 cycle outboard probably from the 80's . Should there be water coming out of the tell tale tube when the motor is first started or does a thermostat stop the flow until the motor is hot? About how long should we wait for the water to come out of the tell tale before we panic? Thanks Doug Com-pac19 Lake Guntersville, Alabama
Doesn't sound right to me, but I don't know the specific OB.
Here's a pdf from Tohatsu for 5 HP carbureted 2-strokes, with and without the internal tank. Doesn't give a model year. Page 8 says check for flow after starting. No mention of waiting until it warms up. It doesn't have a parts diagram, but you could look for that if you wanted to verify for sure that there is or isn't a thermostat.
http://www.tohatsu.com/tech_info/own_man_pdfs/Toh5B_5BS.pdf
Most blockages for me have been corrosion right at the discharge hole, and easily cleared. Good luck!
It can take a few seconds for water to pump through the system but you should see something regardless of engine temp within 20 seconds. If you don't you need to check the impeller, because even if it's a blockage the impeller is likely shot from overheating. I'd get the whole kit with gaskets and housing. And with it apart check all the passages both inlet to pump and through to outlet. It's common for sand and such to clog things up. And if you find any chunks or vanes missing from the impeller those can get stuck inside too.
The tell tale stream is separate from the actual cooling circuit. It is just there to tell you that you have circulation. If you have a thermostat it will not stop the tell tale stream, it should come on immediately. You could have a problem with your impeller or more often you could have a spider web or dirt dauber plug in the tell tale pipe. Poke something up there and if that is not successful then tear it down and check the water pump. Not a big or complicated job.
Thanks for the advice. A local repair shop suggested I run the motor for 5 or 10 minutes to see if the thermostat would open.
Doug Guntersville,AL
Everyone else is correct. Water should come out of the telltale right away. In a motor that old you should change the impellor anyway. Spark plug, lower unit lube, impellor, etc. is regular maintenance. There are lots of UTube videos showing how a do-it-yourselfer can complete all of these jobs. Never trust the person before you in ownership. AND don't forget to use ethanol free, high octane gas in every small engine.
Thanks again for the feedback. The problem has been perhaps temporarily fixed by a local shop who used air pressure to back flush the tell tale. The previous owner had used the motor in salt water and maybe not flushed it. As noted by you folks the water appears from the Tell tale very quickly with a good flow. Doug com-pac19 "Adagio" Guntersville AL
water should come out instantly on most engines, if not all(well everyone I've ever seen)
My smaller outboards, Tohatsu 6hp 4 stroke and Yamaha 4 hp 4 stroke, will push water out just by turning the engine over with the pull chord....