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Discussion » Questions » Science and Technology » What will running a 2cycle engine do if ran at double the fuel/oil mix?

What will running a 2cycle engine do if ran at double the fuel/oil mix?

Ski Doo was worked on and the mechanic said put oil in fuel at 20:1 and still put the oil in the injector. Does this make for a 40:1 mix? And will it hurt the engine? (older engine 1992)

Posted - August 19, 2018

Responses


  • 14795
    To much oil in a two stroke engine does far more damage than a leaner  mixture....you should never over oil ...
      August 19, 2018 5:38 PM MDT
    3

  • 14795
    You need to drain the fuel and refill with the correct mixture....if you've only started it and run it for a minute ,most likely it not damaged as the engines not got up to running temperature ....
      August 19, 2018 5:43 PM MDT
    2

  • 34415
    Thank you. It has been ran this way for a month or so...probably 10-12 hours. The kids have been taking it out. We just found out what the mechanic told them. Kind of blew our mind. We just planned on unhooking the injection pump since they are premiximg the fuel. 
      August 20, 2018 4:59 AM MDT
    2

  • 10026
    Hi my2cents~ I don't know anything about Ski-Doos but I tried and found these links.  I'm hoping they go through.  If not, please let me know and I'll try to send them another way.  The last one might be the best.  I think they are online to ask directly, anytime.  I hope these help.  Good Luck! :) :)

    https://www.snowmobileforum.com/general-sled-chat/88314-oil-injection.html
     
    I've been weary of it, because my friends kawasaki zxi 900 (jet ski) blew up. ... My 1978 yamaha exciter, and 1992 yamaha phazer both have oil injection, and .... I think ski-doos typically die rich; whereas Polaris goes lean during failure. ... Personally I have put over 6000 miles on my 1979 Yamaha Exciter and never had a ...

    https://www.snowmobileforum.com/ski-doo.../71021-2000-mxz-oil-issues.html
     
    Jan 9, 2013 - 1992 Ski Doo Mach 1 (SC-10/2 suspended) March '07 SF.com Sled of the Month! ... Remove the oil injection line going to that cylinder and start it. ... So what do you think if both oil lines are putting out the same amount of oil to ... oil that has flooded the bottom end in the cylinder on the clutch side also I want ...

    https://www.denniskirk.com/blog/.../what-to-do-when-your-snowmobile-wont-start/
     
    Dec 16, 2013 - If you have over-choked the sled while trying to start it, theengine could become flooded. ... Clean the plug and put it back in. ... Youwill also want to make sure that your fuel pump, fuel lines and ... Thecylinder needs to have enough compression to compress the .... Hi I have aski doo formula z 518 (9994).

    www.justanswer.com/Injector‎
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      August 19, 2018 5:59 PM MDT
    2

  • 34415
    Thank you. Links worked great. 
      August 20, 2018 5:09 AM MDT
    2

  • This will double the oil, but not the fuel.  It will run A LOT cooler and probably foul spark plugs.

    How long did the Ski Doo mechanic tell you to do this?

    Sounds like he wants to run the engine cooler than normal because of a "rebuild" scenario.  Did he replace the rings and/or bearings?

    "If it is a "break-in" strategy, I'd be more comfortable running the correct mixture and just babying the engine for XXX amount of hours."

      August 19, 2018 10:18 PM MDT
    4

  • 34415
    No engine rebuild. It was cutting out after a while acting like it could get no fuel. Changed lines etc. But no engine rebuild. 
    He told them to put in the fuel and in the injection pump. Told them older engine needs more oil. 

    I am confused. I have read that more oil makes it run hotter....then I read cooler. If cooler then it could make sense for an older engine....IDK. 
      August 20, 2018 5:16 AM MDT
    2

  • https://hw.menardc.com/main/items/media/PINNA017/Prod_Tech_Spec/2-Cycle_Oil_Information.pdf

    (
    read the last two paragraphs) ... next to last paragraph states that the oil is THE ONLY lubricant and without lubricant the engine overheats.

    So your mechanic is changing your gas/oil ratio from 20:1 to 20:2.  Same amount of gas, twice as much oil ... 10:1.  It will definitely run cooler, if it runs at all.  :)   (That's a big ratio change)
      August 20, 2018 6:14 AM MDT
    1

  • 22891
    have no idea
      September 9, 2018 4:54 PM MDT
    1