Reply
 
Thread Tools Search this Thread
 
Old 03 September 2014, 12:08   #1
PJT
Member
 
Country: UK - England
Length: 3m +
Join Date: Feb 2014
Posts: 2
Tohatsu 9.8 two stroke, starts well, no power

Hi,

Just bought a very clean 2006 Tohatsu 9.8 2 stroke with low hours. No power though and sounds like off a cylinder when reved

Starts easily.
Idles well.
At low revs, sounds perfect.

Out of gear
- up to half throttle, revs climb steadily and sounds perfect.
- up to full throttle, revs high and then revs drop, does not stall. Sounds like off a cylinder....

In gear/under load
- revs to about 25%, giving out not much power......1980s 4HP is faster :-)

So far (with no difference)
- New fuel always used
- Carb cleaned x2 (perfect)
- New plugs

Something electrical perhaps ?

Advice much appreciated. Thanks.
__________________

__________________
PJT is offline   Reply With Quote
Old 03 September 2014, 14:26   #2
Member
 
Country: UK - Wales
Town: abergele
Boat name: all mine
Make: ribtec 3m
Length: 3m +
Engine: tohatsu 9.8 hp 2st
Join Date: Sep 2012
Posts: 275
take one plug lead of and see if it starts (dont run for to long) check fuel filter engine side and filter in the fuel tank when you say clean carb have you soaked it for 24 hours in cleaner with everything removed ?? electrical could be a coil, cdi, leads, have you checked that both plugs are sparking??
__________________

__________________
slate1234 is offline   Reply With Quote
Old 03 September 2014, 14:29   #3
Member
 
Country: UK - Wales
Town: abergele
Boat name: all mine
Make: ribtec 3m
Length: 3m +
Engine: tohatsu 9.8 hp 2st
Join Date: Sep 2012
Posts: 275
9.8hp on a 4m+ now that's hoping
__________________
slate1234 is offline   Reply With Quote
Old 03 September 2014, 19:45   #4
Member
 
m chappelow's Avatar
 
Country: UK - England
Town: yorkshire
Boat name: little vicky
Make: avon ex RNLI
Length: 3m +
Engine: tohatsu
Join Date: Mar 2008
Posts: 2,310
Tohatsu 9.8 two stroke, starts well, no power

I had same problem with a near brand new Tohatsu a few years ago 10 hrs running ,
Turned out to be a crack on a spark plug ceramic insulator , it would start ist pull & run fine upto 3/4 power then it would drop off & go onto one cylinder , at first without really close inspection the plug looked fine , but what was happening is the broken insulter was vibrating up & down down the electrode shutting the spark off the tip then was shorting out back up inside the plug .
New plug & has been right ever since ,, though you did say earlier you had replaced the plugs ?
__________________
m chappelow is offline   Reply With Quote
Old 04 September 2014, 04:31   #5
PJT
Member
 
Country: UK - England
Length: 3m +
Join Date: Feb 2014
Posts: 2
Thanks for advice. Will investigate further
__________________
PJT is offline   Reply With Quote
Old 10 September 2014, 04:37   #6
Spammer
 
Country: Canada
Town: Southern Ontario
Boat name: -Unknown-
Make: SeaMax
Length: 4m +
Engine: Merc/Minn Kota
Join Date: Mar 2012
Posts: 216
Switch box, loose magneto or Mag connectors or bad coil. Start by tightening Switch box after sanding off any rust or corrosion to where box attaches to block ; same with both coils. Look for cracks in insulation of both plug wires. When it does giving problems. Shut-down check each plug see if one is wet with fuel. If one is, 1/2 the battle is done if repairing it.
__________________

__________________
Nightfisher is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 20:29.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.