Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 15-01-2010, 11:00   #1
Registered User

Join Date: Jan 2010
Posts: 1
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?
Gaff756 is offline   Reply With Quote
Old 16-01-2010, 06:38   #2
Moderator Emeritus
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 29,364
Images: 240
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?"

GordMay is offline   Reply With Quote
Old 16-01-2010, 08:21   #3
Senior Cruiser
S/V Antares's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Annapolis, Bahamas
Boat: 1983 Gulfstar 36
Posts: 1,240
Images: 1
Where are you? Did the engine run ok after the valve work?
Will & Muffin
Lucy the dog

"Yes, well.. perhaps some more wine" (Julia Child)
S/V Antares is offline   Reply With Quote

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tohatsu 18hp Two-Stroke, Anyone? sobriyah Engines and Propulsion Systems 2 14-01-2010 19:22
For Sale: Tohatsu 3.5hp 4 stroke (Martha's Vineyard) benjiwoodboat Classifieds Archive 0 17-08-2009 11:00
For Sale: '07 Tohatsu 3.5hp 4 Stroke benjiwoodboat Classifieds Archive 0 26-07-2009 06:40
Yanah 15HP vs. Tohatsu 18HP (2-Stroke OB) The_PIRATE Engines and Propulsion Systems 2 28-08-2007 12:34
Nissan/Tohatsu 4 stroke Outboard? exposure General Sailing Forum 7 19-07-2005 17:15

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 12:37.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.