Page 1 of 3 123 LastLast
Results 1 to 10 of 22
  1. #1
    Join Date
    Apr 2003
    Posts
    37

    Default Outboard 2 stroke ratios

    Recently purchased a Mariner 4hp 2 stroke but what is the correct petrol/2 stroke mix ratio, I was told it is 100-1 is this correct? what ratio do you use and would I see an advantage in performace if for example I use a mix ratio of 100-1 rather than say 50-1?

    Thanks
    CC

    <hr width=100% size=1>

  2. #2
    mainshiptom's Avatar
    mainshiptom is offline Registered User
    Location : Faversham kent uk
    Join Date
    Jul 2002
    Posts
    3,172

    Default Re: Outboard 2 stroke ratios

    I have the same engine !

    I tend to put 100ml for every 5 liters.

    100/5000=1/50

    Tom

    <hr width=100% size=1>

  3. #3
    DavidJ's Avatar
    DavidJ is offline Registered User
    Location : home Brum, boat Costa Brava
    Join Date
    Jun 2001
    Posts
    3,361

    Default Re: Outboard 2 stroke ratios

    Be very careful with this one. I have a 4hp Marina bought some 5/6 years ago which is 50:1 It is highly likely that they changed to 100:1 at some stage.
    If you use 100:1 in a 50:1 machine it with seize
    If you use 50:1 in a 100:1 machine you will get pre ignition and eventually damage the engine.
    Suggest contacting the manufacturers with the seriel no.

    <hr width=100% size=1>

  4. #4
    Join Date
    Apr 2003
    Posts
    37

    Default Re: Outboard 2 stroke ratios

    Tom,

    Do you use it on a 2.80 inflateable? mine is on a 2.80 Avon Rover I haven't used it yet (roll on the weekend)! how many knots would I expect? I have seen a few inflatables on our local stretch of river looks good fun

    <hr width=100% size=1>

  5. #5
    Join Date
    Nov 2002
    Posts
    19,761

    Default Re: Outboard 2 stroke ratios

    I've got a 2hp Mariner and that's 50-1, so p'raps its a Mariner thang.

    Try it out and see what colour smoke comes out; if little or none, then you've got it more or less right. I can't remember (tho' thousands will no doubt leap in at this point) but white smoke=not enough oil and grey/black smoke= too much, I think? (Flames = outboard b*&&ered).

    <hr width=100% size=1>
    Itis apis spotanda bigon etoo

  6. #6
    jfm's Avatar
    jfm is offline Registered User
    Location : London/Antibes
    Join Date
    May 2001
    Posts
    17,447

    Default Re: Outboard 2 stroke ratios

    Davidj is right on. They used to be 50/1, now 100/1. You need to be precise about which motor it is. Post a pic maybe. If it is the Tohatsu 4hp that is bort by Merc and painted in mariner/mercury colours, and &lt;5years old, then 100:1. If any doubt, use 50/1 till you're sure, as the 100/1 motor will run ok ish on 50/1

    <hr width=100% size=1>

  7. #7
    Join Date
    Apr 2003
    Posts
    37

    Default Re: Outboard 2 stroke ratios

    It is the one with a grey cover and brown/red/orange/bright orange stripes running horizontally it also has foward/neutral/reverse gears and the option for an external fuel tank...does this help? maybe I need to get in contact with mariner, is it british or an american manufacturer? or any ideas on where they are located?

  8. #8
    Join Date
    Apr 2002
    Posts
    472

    Default Re: Outboard 2 stroke ratios

    I used to have a Yamaha 20. I thought that the ratio was 50/1 but it ran like ****. Then I found out that it should be 100/1 and it ran brilliantly. So at the very least it makes a difference to the running of the engine even before you take into account that it will damage it.

    <hr width=100% size=1>

  9. #9
    DavidJ's Avatar
    DavidJ is offline Registered User
    Location : home Brum, boat Costa Brava
    Join Date
    Jun 2001
    Posts
    3,361

    Default Re: Outboard 2 stroke ratios

    Mine (50:1) model has no option for external fuel tank but I wouldn't like to guess in conclusion that you have the later (100:1) model
    I don't believe the smoke is the test, by the way, because it all comes out...The 50:1 will be smoky, run on both machines.

    <hr width=100% size=1>

  10. #10
    jfm's Avatar
    jfm is offline Registered User
    Location : London/Antibes
    Join Date
    May 2001
    Posts
    17,447

    Default Re: Outboard 2 stroke ratios

    That description doesn't prove it but if it has the external tank option and a valve on the port side that swings 90deg to select external tank then it sounds like the later 100:1 model. These run ok on 50:1 and the running in period requires that ratio, but they start much better on 100:1 becuase the petrol atomises better with less oil.

    Mariner is part of Mercury, ie part of Brunswick based in USA, they own Sealine, Searay and loads of other boat firms. You cannot contact them directly AFAIK, too big. The importer is EPBarrus I think. There are lots of spoddy US forums that can tell you all you need on merc/mariner products, but I warn you, get your anorak on :-)

    Eg <A target="_blank" HREF=http://www.pfs-ware.com/kwast/disc_toc.htm>http://www.pfs-ware.com/kwast/disc_toc.htm</A>.



    <hr width=100% size=1>

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •