Tachometer overspeed on Tohatsu 40H

[hashdonkey]

I've been running my Tohatsu 40Hp 2-stroke without any problems until a few days ago when it started Ok but cut out as soon as I increased the revs. After disconnecting and reconnecting the fuel line at the tank this problem went away but ever since then the tach goes right off the guage as soon as I put it into forward and increase the power. I'm certain the engine's not doing the 7000+ rpm the guage says it is at full throttle, nor the 5000 rpm it now shows before the boat even planes. I've gone through the wiring from the engine to the tach and there doesn't seem to be any problem, does anyone have an idea what might have happened? It seems strange that this started immediately after the fuel line problem. Thanks.

 

[TOHATSU GURU]

Re: Tachometer overspeed on Tohatsu 40H

The fuel system can't affect the tach so the problem is not related. Off hand it sounds like you spun the hub in your propeller.

 

[hashdonkey]

Re: Tachometer overspeed on Tohatsu 40H

Thanks Elvin, excuse my ignorance but what does spinning the hub in the propeller entail? If this is the problem is it safe to continue using the motor until I can get it fixed, we're in the middle of the Pacific boating season at present and I'd rather leave the repair until after Christmas if possible.

 

[TOHATSU GURU]

Re: Tachometer overspeed on Tohatsu 40H

Your propeller is made up of multiple parts that are melded together. The center splined part is revolving inside the section that has the blades on it. You can either get that prop fixed or buy a new one, but you need to do one or the other before you use your boat again.

 

[hashdonkey]

Re: Tachometer overspeed on Tohatsu 40H

Thanks Elvin, I'm onto it.