Break in period with low oil to gas ratio

Discussion in 'Motorized Bicycle General Discussion' started by arguevera, Jul 16, 2017 at 10:12 PM.

  1. arguevera

    arguevera New Member

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    Some backstory first:
    • Engine is a typical ebay 80cc 2 stroke kit
    • When I first mixed the fuel, I negligently calculated the ratio wrong and ended up with 2 gallons of mixed fuel with a ratio somewhere between 32:1 and 40:1.
    • I have used up almost the entire 2 gallons.
    • The bike has been rode for around 100-150 miles so far (for the past 20 days).
    • The climate where I live is generally cool (San Francisco)
    • During this break in period, RPMs ranged between low and high, but cruising was always low to medium.
    • During this break in period, there was a lot of uphills (SF) and in some cases I had to assist by pedaling.
    • Break in period seemed to go good as the engine developed a lot of power during the period.
    • Engine has no problem starting or idling
    Basically I just realized I have been running with quite a low oil to gas ratio for the break in period and was wondering if it seemed to have gone great, is there any underlying damage that could have occurred? For example, I know that piston and cylinder walls can be scored and damage can be done to the piston rings, but all those would result in a loss of power. If my power has only been improving during the period, can I assume that no damage has been done?
     
  2. Chaz

    Chaz Member

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    Welcome to the forum. I would say that you don't have anything to worry about. I have read here that many very experienced builders will use the mix ratio that they plan to use permanently as the break in ratio as well. There are many opinions on breaking in but I believe the key is just don't overheat and vary the rpm which is exactly as you did so you're fine.
     
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  3. arguevera

    arguevera New Member

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    Thanks for the reply! So in all, since there was no catastrophic failure and the engine power increased during that time, the worse that could have happened was some increased wear?
     
  4. Chaz

    Chaz Member

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    You did everything right. I would say you've only got normal wear.

    I don't know what oil you are using but for long term use I think full synthetic is the way to go. I followed some advice here and on one engine I used dino oil for the break in and then switched to synthetic. The theory is that synthetic is too slippery for break in and may not seat the rings properly. Who knows, but there is some logic to it and it worked fine for me.
     
    #4 Chaz, Jul 17, 2017 at 12:43 PM
    Last edited: Jul 17, 2017 at 12:53 PM
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  5. arguevera

    arguevera New Member

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    Okay sounds good, thanks for the advice!
     
  6. xseler

    xseler Active Member

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    All above is correct. 'Broke' mine in at 32:1 for the first gallon. Run it at 50:1 thereafter. It's been 4 1/2 years now ---- it runs better now than when it was 'newer'! I've only ran synthetic Echo oil since the beginning.
     

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