Tohatsu 50 mystery

A forum for discussing topics relating to MacGregor Powersailor Sailboats
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gyroplanes
Engineer
Posts: 197
Joined: Thu Nov 06, 2008 12:23 pm
Sailboat: MacGregor 26X
Location: Lansing, Illinois (Chicago, so suburb)

Re: Tohatsu 50 mystery

Post by gyroplanes »

I just got off the phone with 2 dealers.
After the usual items we all guessed at, he said to try unplugging the wiring harness form the power throttle quadrant. I find it hard to believe it is a bad switch because it is so predictable.
Dealer 2 said it could be a spider nest in the carb float vent. It would have to be one carb for all three for that to be the deal. I can't remember if I have 1 carb per cylinder or 1 for all three.

I will try these things and then, if that doesn't work, introducing fuel into the intake externally, at the time of shut off (duct taped very small hose to inlet hooked to a squeeze bottle) If the oil bearing fuel doesn't revive it, it's probably got to be electrical.

I hope a spider cramped my speed. I'd like to clean out a nest and maybe hit the advertised speed number instead of the 10 MPH tops with fins up, ballast and 4 adults on board. :-) come on spidey
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Russ
Admiral
Posts: 8342
Joined: Thu Oct 11, 2007 12:01 pm
Sailboat: MacGregor 26M
Location: Bozeman, Montana "Luna Azul" 2008 M 70hp Suzi

Re: Tohatsu 50 mystery

Post by Russ »

gyroplanes wrote: it shuts down fast, like a shut off key (or safety lanyard pulled) and will restart and run just fine in a few seconds after cranking.
This makes me think electrical or as mentioned above, some kind of safety cut off. Overheating is my guess. If it were fuel, you'd hear it gasp. We all recognize the sound of starving for fuel (don't we). What you describe is something is shutting the switch off.

Now what makes me think overheating is that you say it cuts off after a few minutes. So it reaches high revs, just can't maintain them. If it were the throttle control safety switch, you'd get shut down as soon as you punched it. Yea, sounds like somethings heating up and shutting you down.
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parrothead
First Officer
Posts: 426
Joined: Sun Mar 06, 2005 7:25 am
Sailboat: MacGregor 26M
Location: Former vessel: '05 M "Blue Heaven" - Nissan 50 TLDI --- Now owner of a Gemini 3400

Re: Tohatsu 50 mystery

Post by parrothead »

How healthy is the "pee" stream? Our 50hp Nissan TLDI {a Tohatsu of another color} exhibited similar symptoms last season. A reduction in water flow was resulting in vapor lock.
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