Reply
 
Thread Tools Search this Thread
 
Old 08 February 2023, 08:54   #1
Member
 
maverick58's Avatar
 
Country: UK - England
Length: 4m +
Join Date: Jul 2018
Posts: 83
Tohatsu fuel ratio.

Morning all. Iíve just taken ownership of a 2005 tohatsu 9.8 2 stroke. I know tohatsu recommend a fuel/oil ratio of 50:1, I fired her up for the 1st time yesterday and it smoked like hell even after running for 5 mins, which Also produced some oil residue around the back of the prop. My last 2 stroke merc was 100:1. Can anyone shed some light on that exact same engine and what they run fuel/oil. Itís definately running too rich. Many thanks. Click image for larger version

Name:	IMG_4050.jpg
Views:	47
Size:	67.7 KB
ID:	142112
__________________

__________________
maverick58 is offline   Reply With Quote
Old 08 February 2023, 12:12   #2
Member
 
Country: UK - Scotland
Make: Destroyer 5.5/Ring18
Length: 3m +
Engine: Yam 90HP/Yam200HP
Join Date: Jul 2009
Posts: 875
Fenlander may see this post and reply, heís an expert on this engine
__________________

__________________
69cmw is offline   Reply With Quote
Old 08 February 2023, 13:12   #3
Member
 
chipko's Avatar
 
Country: UK - England
Town: Up North and right a bit
Make: XS500/Merc340/Bic245
Length: 5m +
Engine: Mar 60/20/3.5/Hon2.3
Join Date: Sep 2013
Posts: 843
That looks ace.

Can confirm they run 50:1
Tohatsu recommend you run in for the first 10 hours at 25:1. As good practice we also fire ours up initially at 25:1 on half a tank at the start of the season.

Ours is a tad smoky at tickover on 50.1 and even tolerates the 25:1 without foulingÖ.mind you we donít faff around much at trolling speeds.
__________________
chipko is online now   Reply With Quote
Old 08 February 2023, 16:20   #4
RIBnet Supporter
 
willk's Avatar
 
Country: Ireland
Length: no boat
Join Date: Feb 2008
Posts: 14,492
Quote:
Originally Posted by maverick58 View Post
I know tohatsu recommend a fuel/oil ratio of 50:1Attachment 142112
I had one of these - 50:1 is correct. Unless you are running at high revs all the time you will get residue. If you are a potterer, then I would suggest that you might consider 75:1. The previous keeper of my engine was a fisherman and he ran it on 100:1 - it didn't seem to cause any issues with it.
__________________
Who knows what evil lurks in the hearts of men?
willk is offline   Reply With Quote
Old 09 February 2023, 10:32   #5
Member
 
Country: UK - England
Town: East Anglia
Boat name: Nimrod II
Make: Aerotec 380
Length: 3m +
Engine: Tohatsu 9.8 2-stroke
Join Date: Nov 2007
Posts: 7,640
I’ve owned two of these and done the 10hrs running in at 25:1. Even at that oil heavy mixture I didn’t find the smoke terrible. I now use 50:1 and it’s fine. I always use Quicksilver oil, what’s your brand of choice?
Are you adding anything to the oil like a stabiliser! Are you 100% sure of your mix ratio?
__________________
Fenlander is offline   Reply With Quote
Old 09 February 2023, 18:18   #6
Member
 
maverick58's Avatar
 
Country: UK - England
Length: 4m +
Join Date: Jul 2018
Posts: 83
Quote:
Originally Posted by Fenlander View Post
Iíve owned two of these and done the 10hrs running in at 25:1. Even at that oil heavy mixture I didnít find the smoke terrible. I now use 50:1 and itís fine. I always use Quicksilver oil, whatís your brand of choice?
Are you adding anything to the oil like a stabiliser! Are you 100% sure of your mix ratio?

Iíve been using 2 stroke outboards for quite a few years so itís deffo the right ratio. Fresh fuel and fresh quicksilver too. When some 2 strokes run at 100:1 I must admit a 100ml of oil does seem like a lot for just 5Lís of fuel. Pulled the plugs and they seem to be a bit wet indicating over lube & running rich. Previous owner was adamant he ran at 100:1 plus a bit on top for good measure.
__________________
maverick58 is offline   Reply With Quote
Old 01 March 2023, 19:41   #7
Member
 
Country: Greece
Join Date: Mar 2023
Posts: 2
Hi all. My first comment here. Questions! How do I actually create a post? I'm looking to buy a Tohatsu 9.8 2 stroke. I am in Greece, and of course can not buy new. I have found a seller in the Channel Islands but not sure if it's the way to go. I'd like to create a new post entirely and source information and insights. Thank you kindly, Hinton
__________________
Hinton is offline   Reply With Quote
Old 01 March 2023, 20:16   #8
Member
 
maverick58's Avatar
 
Country: UK - England
Length: 4m +
Join Date: Jul 2018
Posts: 83
Quote:
Originally Posted by Hinton View Post
Hi all. My first comment here. Questions! How do I actually create a post? I'm looking to buy a Tohatsu 9.8 2 stroke. I am in Greece, and of course can not buy new. I have found a seller in the Channel Islands but not sure if it's the way to go. I'd like to create a new post entirely and source information and insights. Thank you kindly, Hinton

Click image for larger version

Name:	IMG_4141.jpg
Views:	18
Size:	58.8 KB
ID:	142275
Tap the highlighted button and create post. Choose a section to post your Q to. Do they not have 2nd hand tohatsuís in Greece?? The channel island supplier might be able to arrange international shipping from their end. Or perhaps find the tohatsu distributor for your country.
__________________
maverick58 is offline   Reply With Quote
Old 01 March 2023, 21:33   #9
Member
 
Country: Greece
Join Date: Mar 2023
Posts: 2
@maverick58 Hi. Thank you. Unfortunately they are not available in Greece or the EU due to emissions regulations. Also, there are none currently in the used market. I think, when they do show up, they are expensive and bought up quickly. I stupidly sold my old Johnson 9.9 last week, but now have decided to go with a bigger RIB, and so I need a strong, lightweight engine again. Seems a 2 stroke is the way to go. I'll be creating a post shortly! Thanks again, Hinton.
__________________

__________________
Hinton 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




All times are GMT. The time now is 06:44.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.