Blogging bike

Discussion in '2-Stroke Engines' started by geebt48cc, Feb 2, 2011.

  1. geebt48cc

    geebt48cc Member

    New 66cc Skyhawk with 15/miles only. Bike with new CNS and starts/idles good, but wants to blog after idle and then nothing else? I've got another stock muffler that I tried that was opened up some at bottom. Now it runs like it should (not going over 20mph do to break-in) ...Mix 16:1,NGK B6,free flow filter only.

    I slowly sealed intake both carb and attachment to engine.............zero leaks

    Any ideas?

    Glen
     

    Attached Files:

    Last edited: Feb 3, 2011

  2. motorpsycho

    motorpsycho Active Member

    you mean BOG?
    95% of the time, a bog is caused by an air-fuel ratio that is too lean.
    It could be one of 3 things, either your air-fuel ratio is too lean, you have an air leak (which you said that you didn't have) or the muffler is plugged up.
     
  3. geebt48cc

    geebt48cc Member

    Yes, Bogging............So, when you get motor kit, do you think stock muffler could of been plugged up before installed? See, only have 14.8 miles on new motor. You can see in last picture that I've really gone over and sealed for air leaks. It can't be lean, because with a couple of plug chops it's always wet at 16:1.

    ?? Thanks
     
  4. motorpsycho

    motorpsycho Active Member

    well, you are getting the fuel-oil ratio mixed up with the fuel-air ratio.
    If your plug is wet, that means there is too much oil (because you are running at 16:1) if your plug is wet with a 32:1 ratio (a lot less oil), then your carb is too rich on the fuel-air ratio which would mean that you would need to re-jet your carb leaner with a smaller jet.
    but again, your fuel-air ratio could be too lean which would mean that you might have to re-jet the carb with a bigger jet. air-fuel ratio and oil-fuel ratio are 2 different tnings,and normally the fuel-oil ratio is not really described as rich or lean. so really, your plug can be wet with a lean jetted carb, and a high oil-gas ratio.
    I have found that MOST of the time, the stock n.t. carbs are jetted too lean from the start. My 66 c.c. had a .70 jet in it and i had to go up to a .74 to get it to run right. my 50 c.c. has a .70 jet in it as well, and it runs just about perfect with the smaller jet because it's a little less c.c.'s.

    It's doubtful that the new muffler is clogged up already, but running a 16:1 fuel-oil ratio, allows a ton of oil to be blown out of the exhaust. so who knows, maybe your muffler is clogged already.

    I love it when someone asks a question, and when someone gives them the answer they say "no, it can't be that."
     
  5. geebt48cc

    geebt48cc Member

    No,No, I'm all ears! Do you believe that I should just start out with a lighter mix........say jump up to 25:1? Note: Its only got 15 miles total at this point.
     
  6. motorpsycho

    motorpsycho Active Member

    I can't speak for everyone else, or say what's "right" but i broke both of my engines in on 20:1 non synthetic 2 stroke oil.
    after i ran about 2 tanks of the 20:1 mix, i went to a 32:1 mix with synthetic 2 stroke oil.
    a lot of people will say that 16:1 is just too much oil, even tho most manufacturers say to break in these engines with a 16:1 mix.
    i feel that a 20:1 mix is still enough oil for break in, but you might want to get other opinions on that because everyone has different ideas.
     
  7. geebt48cc

    geebt48cc Member

    Yes synthetic is the stuff, I'm also going to synthetic (Amsoil) after the first few tanks. Uno, So, didn't you just get a new CNS carb? If so, be honest and tell me what you think?

    Glen
     

    Attached Files:

    Last edited: Feb 3, 2011
  8. motorpsycho

    motorpsycho Active Member

    well, i got a cns clone carb. same style, different manufacturer. It's made by Wabro, and it is exactly like the cns carb.
    I out it on and my engine ran great, but it was a tad too lean for me.
    I tried to re-jet it, but the threads in the delorto jets are too small to fit in it.
    So, i ran this carb for about a day and took it back off.
    it ran great right out of the box other than it's jetted too lean.
    so, i took the stock nt carb, and re-jetted it, which made my engine run 10 times better than when it had the stock jet in it.
    I still have my cns clone carb and a high flow air filter for it, but it's just sitting in a box right now.
     
  9. geebt48cc

    geebt48cc Member

    Nice............Well, I guess this is a clone CNS as well. See, it's titled as a CNS, but SKYHAWKS version that comes with 66cc kit. I just had it out for a few miles, and chain seems to keep jumping off. Heck, my last 48cc GT2 Skyhawk kit went on without any problems last year, and is still doing well. This one doesn't seem like it wants to cooperate? No, I should of known that there would be issues considering it went together so well..............
     
Loading...