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Old 15-01-2010, 11:00   #1
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Tohatsu MFS9.8AS Four-Stroke Problems

I own a tohatsu MFS9.8AS 4-stroke. The motor does fine idiling in neutral and acceration in neutral but when engaged in gear it will not accelerate, acts as if the EFS is activated but oil light is not on. I recently had the motor worked on because the valve keepers had came off. the mechanic said it had over reved at some point. I didn't beleive that then nor do i now. came you advise me what to check for?
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Old 16-01-2010, 06:38   #2
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Greetings and welcome aboard the CF, Gaff.

They probably won’t help with your current problem, but FWIW, here’s the Tohatsu Owners’ Manuals:
Tohatsu Outboards: Authorized North American Distributor for Tohatsu Outboard Motors, Parts, & Accessories.

Including the 9.8A:

Including the 9.8A3:

Service & Parts manuals for Tohatsu outboards are available from Clymer Manuals and can be ordered at 1-888-708-4703, or
Tohatsu marine repair manuals from

Good luck!
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"

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Old 16-01-2010, 08:21   #3
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Where are you? Did the engine run ok after the valve work?
Will & Muffin
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"Yes, well.. perhaps some more wine" (Julia Child)
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