Tohatsu

[BrenBray]

Hi all. I am in desperate need of help. I have a 1995 Tohatsu M50D that is absolutely driving me nuts! The motor starts and idles fine, stumbles and lacks power when fully advancing the throttle. When it finally is able to bring the boat up on a plane, it runs pretty good, but still does not seem to be at max rpm's (no tach to know what the rpm's are). It seems as though I can run approximately five minutes with no problems, then the motor suddenly seems to cut back to idle, I shift into neutral then the motor usually dies. Most of the time I can restart the motor and get back up on a plane for only a minute before we go through the same thing again. I have changed all three spark plugs, cleaned the fuel filter, rebuilt all three carbs, changed all of the fuel lines, rebuilt the fuel pump, and I am using an external fuel tank with a new fuel line and primer bulb. Here's a question, how hard should the primer bulb stay? I've heard hard and some say it will be somewhat soft. Please help, I'm at wits end. Any comment or suggestions will be much appreciated.

 

[TOHATSU GURU]

Re: Tohatsu

The bulb should be firm. Sometimes that means rock hard, but usually you can still still squeeze it. To troubleshoot your engine follow the steps below:

1) Buy a service manual.

or

2) Take it in to a dealer.

Outboard engines are a made up of a complex group of separate systems. It takes years of training to learn how to diagnose and repair them if the problem is anything other than minor. If you still want to try this yourself there are three basic tests to perform before you do anything else.

1) Check compression

2) Check for fire on all three plugs(Hint...Check when the engine is NOT running correctly)

3) Check you gear oil

4) Clean your carburetors...Again.

 

[BrenBray]

Re: Tohatsu

What do reed valves do? Would this possibly be a cause to the problem?

 

[TOHATSU GURU]

Re: Tohatsu

Think of the reeds as the gate keepers of the engine block. They open and close with each engine revolution allowing the fuel in so that it can explode and move the pistons. A reed could be bent or broken and that would cause the engine to run poorly, however, it would run poorly all the time.