Tohatsu 50 2 Stroke

Hi there,

Any help here would be much appreciated. The engine is on a Zapcat and should do about 50mph. At the moment we are lucky to get 20 out of it. It has had the carbs stripped with new reeds, its got new plugs and has fresh fuel running a 50:1 mix. We did accidently run a mix with far too much oil in which was causing stalling and delayed acceleration. SInce then the fuel has been changed and the plugs cleaned. We are still not getting any top end speed and the acceleration certainly isn't what it should be. The only time the engine did seem to run properly was moments before we ran out of fuel when we were running at full throttle and the boat suddenly accelerated up towards a more acceptable top speed before dying.

Could this be because the fuel/air mix in the carbs is wrong so that just before the fuel ran out the engine was receiving the right amount of fuel instead of too much.

Thanks in advance

ScaredyCat.

Re: Tohatsu 50 2 Stroke

Speaking generically you usually wouldn't notice the difference with too much oil except for more smoke.
Unless you fouled the plugs.I would check the compression then unhook and ground one plug wire at a time and note how it runs.Did you do the carbs by the book? They are not interchangeable.Does it respond to a little choke at wot?Have you tried sqeezing the primer bulb at speed?Have you check the syncronization? Before checking sync check ignition timing.

Re: Tohatsu 50 2 Stroke

Hi, obviously you race with this motor, if it is on a zapcat .... or train with it .... too much oil won't do anything exept smoke alot .... sounds to me like the carbs need to be sync 'ed and make sure the carbs are in their correct order .... did you replace the reeds with standard tohatsu reeds or with boysen reeds? ......

Re: Tohatsu 50 2 Stroke

The symptom is too broad to provide a one stop cure, but, check compression, check for sprark on each of the three cylinders and check your gear oil. If all seem okay then look at the entire fuel system.

Re: Tohatsu 50 2 Stroke

put new plugs in . it is hard to clean a fouled plug and git good performance . it also sounds like it could be running to rich ,