2 stroke 25 hp Tohatsu ???

[Ad88]

Took it out ran fine( pumping water ok) across lake shut it down to fish, headed back home running 3/4 throttle shut down lots of steam. Used trolling motor to get home pulled plugs looked ok, hit starter and fired right up then died??? Replaced impeller 3 years ago, new plugs.
Thanks for any info

 

[Sea Rider]

Welcome to Iboats,

To start with, how old is that 25 HP horse, bought it new, second hand purchase, was it used at sea, was conveniently flushed after use ?

If engine dropped dead while heading back home and with lots of steam, where actually lots of steam, powerhead, peeing port or back middle leg port ? Did lower leg catched any thing, plastic, bag, debris etc that could have clogged all 3 lower water intakes and you weren't aware of this condition ? Is thermo shot ? remove it and check, clean or replace if heavily corrroded, salty.

If engine has experienced an overheat cond due to debris or thermo, will need to re torque current head gasket to specs, if with missing issues while boating specially at 3/4 to full wot, need a new head gasket torqued to 30 NM. Take advantage to clean all water passages from crak case and cylinder head as well. Engine will work and cool much better.

Happy Boating

 

[Ad88]

Bought used, had 5 years with minimal usage. Thinking I may have a clogged water passage as stated above ( hopefully) will clean intakes/ and check thermo tomorrow afternoon, will also re torque head gasket if needed.
Thank You Sea Rider

 

[Sea Rider]

I've heard about and seeen engines to have minimum uses but stored carelessly. The only way to fully clean all interior water passages is removing cylinder head and do it manually, assuming engine has run on salt waters and has huge interior salt layers, crust formations.

In such cases, a direct method less efficient though is to remove thermo, install a water hose there to flush head and crakcase as well with high water pressure for at least 5 minutes, this should clear small clogs throughout all water passages. If thermo is in bad cond, get yourself a new one along thermo gasket.

If you had a overheat cond when going back to Terra Firme, it's mandatory to perform a head retorque to specs. You could bump that 25 into a 30 HP for peanuts cost.

Running engines on fresh and salt waters are two completely different scenarios...

Happy Boating

 

[Ad88]

Upon further inspection -No thermo installed, dropped lu to check water pump, impeller is fine along with housing no grooves and rubber is is in good shape. Will flush using method described from above. How about the 25 to 30 upgrade?

 

[Sea Rider]

If engine doesn't have a thermo install a new one, thermo controls temperature as for the engine to work at its precise temp range. If not engine will work too cold or take too much time to warm up and not run efficiently. There's plenty information about the 25>30 upgrade in this section, a matter to find the entire post as it's long to re post it again.

To start with need to order a 30 HP carb gasket as the 25 HP gasket is air restricted, take advantage to order a thermo and thermo gasket as well.

Happy Boating

 

[Ad88]

Just got thru flushing it out, pee stream is strong, idles great, will order thermo and gaskets. Do you have a suggestion on who to order from.
Thanks
Andrew

 

[Sea Rider]

Can order from Paul (pvanv) in this section. PM him..

​Happy Boating