Just bought the kit and build progress

Discussion in '2-Stroke Engines' started by ghost pedaler, Mar 2, 2010.

  1. ghost pedaler

    ghost pedaler New Member

    First things first. What mixture should I start out for the break-in?
     

  2. professor

    professor Active Member

    Gas and oil.

    Hey, Ghost, welcome to Motoredbikes!
    I don't have one, but have read a lot of posts and you can't go wrong following your kit's directions.
     
  3. AussieSteve

    AussieSteve Active Member

    Yep.
    Generally, about 16:1 is recommended for break-in, then 20:1 forever. (That's what's recommended with many kits.)
    Many will argue, but I've done that and never had problems. Plug never oils up and is always light tan in colour.
     
  4. ghost pedaler

    ghost pedaler New Member

    Sounds good to me. Roughly, on these motors, whats the mileage range for the break-in?
     
  5. AussieSteve

    AussieSteve Active Member

    The instructions with my kit recommended 500km.
    Generally, though, 3-4 tankfuls will pretty well do it.
    Don't baby it too much - rev it out a little, but don't hammer it yet.
     
  6. ghost pedaler

    ghost pedaler New Member

    3-4 tanks sounds ideal. Since you can probably pull 85 - 110 mpg.
     
  7. Fabian

    Fabian Well-Known Member

    I've been a strong advocate of 20:1 fuel/oil ratio, but others have spoken glowing praise of 50:1 or even 100:1.

    Even at 50:1, a percentage of cooling is lost as there is far less oil to absorb heat, a particularly important aspect when travelling at 5 miles an hour on a 100 degree (40 degrees celcius) day with the engine struggling it's guts out on a steep hill and virtually no forward air flow - it's cooking away and the oil is playing an important part in removing heat.

    I'm not sure how the engine would cope with that scenario at 100:1

    I've never had plug fouling issues with 20:1 and that's using an NGK BP8HS
    The only time i've noticed the BP8HS struggle to stay at operating temperature is when idling for a long time whilst cleaning and lubricating the chain.
    Oil naturally falls out of suspension and settles in the crankcase and when the throttle is opened the plug gets a good oil wash and struggles to clear it's throat blowing it out the system- that's the worst it gets.

    Fabian
     
    Last edited: Mar 4, 2010
  8. AussieSteve

    AussieSteve Active Member

    The other good reason for a high oil concentration is that it improves the piston-ring to cylinder wall seal, especially in these horribly made little engines.
     
  9. Fabian

    Fabian Well-Known Member

    Completely agree with your comment: The other good reason for a high oil concentration is that it improves the piston-ring to cylinder wall seal, especially in these horribly made little engines.
     
  10. ghost pedaler

    ghost pedaler New Member

    Well, I got the kit in the mail today.

    I made sure that the screws were tight on the carburetor. I was curious to see what was in the bottom of the carb so, I removed the 2 screws from that cap and saw that there is a plastic round piece in there. I put that round plastic part back in and then screwed the cap back in. But, now it rattles around in the cap?? That can't be right. Was that supposed tensioned in there or something??
     

    Attached Files:

    • carb.JPG
      carb.JPG
      File size:
      132.8 KB
      Views:
      53
    Last edited: Mar 5, 2010
  11. AussieSteve

    AussieSteve Active Member

    The cap is at the top, not the bottom.
    What you're referring to is the float bowl. The plastic donut-shaped thing is the float.
    It will rattle if you shake it when there's no fuel in the carb.
    The float rises with the fuel level in the float bowl and presses on a pair of fingers that in turn close the float needle valve, regulating the fuel flow to maintain a constant fuel level in the float bowl.
    As long as nothing else is loose there's nothing to worry about, at this stage.
     
  12. ghost pedaler

    ghost pedaler New Member

    Thanks for the explanation. I thought maybe something popped off. I guess don't really know anything about carbs. lol
     
  13. AussieSteve

    AussieSteve Active Member

    Glad I could help.
    It won't take long to learn about these carbs, there's not much to them and there's a wealth of information on this site.

    This thread, NT Carb Tuning Basics, has a bit of info and some labelled pics.

    Also, srdavo's Carburetor Assembly Pics is worth a look.
     
Loading...