Mixing 2T Oil

Forums Technical Two Stroke: Help needed Mixing 2T Oil

Viewing 9 reply threads
  • Author
    • #9669
      Neil Evans

      Hello ALL, am fairly new to group and got my TS250/1 running nice now except today I had a problem fuelling up. Here I added petrol (3gallons), then added 3 measures mineral 2T from upturned petrol cap. Tried to mix by shaking bike from side to side. Half a mile down the road she died. At home I stripped and cleaned the oily carb and almost neat oil came out of the petrol tap. Running sweet now but worried for the next time I fuel up.

      So the question is am I doing something wrong or was I unlucky, should I be adding oil first then petrol in the hope for agitation from flowing petrol??

      Any words of wisdom gratefully received

      Many Thanks, Neil from Salford

    • #9670
      ‘AAA Dummy

      put 100ml of oil to 4.6 ltrs of petrol
      regards Tony.

    • #9674
      Neil Evans

      Thanks Tony, that’s what I did, in situ and oil went straight to botttom of tank, despite shaking the bike the oil found its way into carb.

      Was wondering if this happened to others and if there is a solution. Premixing and transferring to tank is not practical on the road.

      Cheers, Neil

    • #9675
      ‘AAA Dummy

      Hi Neil
      Your comment “So the question is am I doing something wrong or was I unlucky, should I be adding oil first then petrol in the hope for agitation from flowing petrol??” is what I normally do and I don’t have any immediate problems running, however if I lay up the bike (and I do) when you go to re-use my bikes they can be temperamental but once warmed up usually things get back to normal.

      I also keep handy a plastic fuel cam with pre mix so if I am getting low I can use this and of course it’s easy to gently shake …..

      ATB Stuart

    • #9676
      Malcolm Thomason

      On pre-mix bikes I always try to pour in the oil alongside the petrol as this seems to mix it nicely. I use a suitable size bottle for 5 litres at a time. Also, switch off the fuel tap before refuelling and give the bike a shake before switching back on. Good two-stroke oil usually mixes quite well, unlike the straight mineral oil we used back in the 16:1 sixties.

    • #9677
      ‘AAA Dummy

      Yes, I had this problem once refuelling a Yamaha yz250. It was virtually empty, i didn’t turn off the petrol tap, and I put the oil in first on its own. I then put the petrol in from the pump and gave the bike a shake to mix it up, but it wouldn’t start as the oil had gone straight into the petrol tap. What I do now is turn off petrol tap, put in half the petrol then all the oil then the rest of the petrol, put cap on, and give it a good shake. I haven’t had a problem doing it this way on my mz

    • #9678
      Richard Smith

      When in constant motorway use I normally fill bike to certain level dependant on price and divide the litres by 0.033 and just pour in how many ML the output of the calculation gives, after the bike has been filled of petrol.

      When my riding is around town I only re-fuel when bike goes into reserve normally put half a tank of fuel in, then empty the 500ml bottle of oil (I use the cheapest mineral I can get in bulk) that I keep with me and then carry on re-fuelling after that has emptied into the tank.

      Interestingly, I’ve never really shaken the bike to agitate mixing. Not had a problem with over-heating (due to lack of concentration of oil after fill up) nor had pure oil coming out of the tap.

      And I’ve done 10,000 miles on my 250 MZ in the past 6 months..!

      • This reply was modified 6 years, 6 months ago by Richard Smith.
    • #9686
      Neil Evans

      Thanks for all your thoughts. I like the half and half measure and will def turn off fuel tap in future whilst refuelling.

      One other thought I had was diluting some of the oil with petrol before dispensing into the tank, but could be a messy way 🙂

    • #9701
      John Latuskie

      Make sure you’re using 1:50 mix not 1:33 as the latter oils up the plug.
      Part fill tank then add oil, no need to agitate tank, no need to turn
      off petrol tap even if it’s on Reserve. By the time you have paid for the fuel the mixing will be complete.

    • #16199
      Paul Rotheram


      I’m a new member who’s just acquired an ES250/2. The book says the mix is 33:1. So far I’ve only ridden the bike a few miles and it did leave a vast smoke trail. Should I change the mix to 50:1 using semi-synthetic oil?

Viewing 9 reply threads
  • You must be logged in to reply to this topic.