49cc is going strong

Discussion in '2-Stroke Engines' started by geebt48cc, Jul 13, 2010.

  1. geebt48cc

    geebt48cc Member

    :jester: Ok, hold your breath, everything on the Skyhawk 48cc is doing what it should. ............and legal too:D

    I was wondering after new NGK plug, Wire, and Air Filter, should I go with a Expansion Chamber............
    Last edited: Jul 14, 2010

  2. Molotov256

    Molotov256 Member

    Short answer: Yes

    Long answer: The only 2 bolt on mods I've noticed any significant performance increase from are expansion exhausts and boost bottles. Boost bottles don't seem to help me go faster, but both of my HT motors run a whole lot smoother with them installed.

    Smart answer: Get additional opinions from more experienced members.
  3. Al.Fisherman

    Al.Fisherman Active Member

    After installing my homemade (PVC) boost bottle we had to turn down the idle. I don't know if it is because of the bottle but we don't have any blow back through the carburetor. Was easier to start, I don't know about speed as I haven't had mine WOT for any length of time on a 0 grade. No personal experience with the EC, but from what others say it is the most noticeable mod as far as the engine goes.


    Attached Files:

    Last edited: Jul 14, 2010
  4. AussieSteve

    AussieSteve Active Member

    Glad you got everything sorted out. My 2c worth - get an expansion chamber. Biggest single improvement to any 2-stroke engine's performance.
  5. geebt48cc

    geebt48cc Member

    I guess I'll order an expansion chamber for it. Uno, on the boost bottle, I was wondering how long it last once installed? Steve, can you give me your opinion on what type of EC you would suggest?

  6. AussieSteve

    AussieSteve Active Member

    I think that the Sick Bike Parts chamber is about the best, from what I've read. (I have one here, not fitted yet.)
  7. geebt48cc

    geebt48cc Member

    Yes, that's who I would go with. Steve, I also wonder if I should do boost bottle with it?

  8. AussieSteve

    AussieSteve Active Member

    Not sure Glen. I have no experience with boost bottles. I've always looked on them as a bit of a novelty, but many guys swear by them.
    Ron knows more than I do on that subject.
  9. MrShorty

    MrShorty Member

    I went with the SBP chamber, and I could feel a difference.
    I made my own boost bottle out of a float that I had in the garage. Doing
    some research before I made it, I found a site that said a boost bottle should
    be within 3cc + or - of the cc's of the motor that it will be used on. Mine is
    exactly 66cc. I know this by going to a pharmacy and buying for a needle less
    syringe and filling it up with water after the hose was on the bottle.

    Attached Files:

  10. geebt48cc

    geebt48cc Member

    Steve, more of me wants to think that novelty is a good description of the boost bottle thing? Guess it can't hurt?

    No, I just think that it's a phycological tactic? Who knows?

    Listen, took plug out after about 5/miles.......(light tan in color now) and very clean.
    Last edited: Jul 14, 2010
  11. Al.Fisherman

    Al.Fisherman Active Member

    Hey, make one and try it, you might be surprised. You can make one for less then $3.00. It's basically the labor (about a hour if you need to measure), fitting the intake nipple takes the longest, that brings up the cost. Mine is also down to the cc, not counting the plastic hose. With the luck out of the first two I made, I'll put them on all builds. Some don't get the same results. Just for info, there is NO part of the brass nipple that sticks out into the intake manifold to hinder fuel/air flow. Instructions on how I built mine if desired, upon request.
  12. geebt48cc

    geebt48cc Member

    Ngk B6hs

    Simple question of NGK plugs,

    So, the B6HS is a good plug for higher outside temps than B5HS?

  13. GearNut

    GearNut Active Member

    It depends on what your engine needs. The higher the plug number, the colder the plug, so the way you stated it, yes. Your engine will have to tell you if it is needed or not though.
    I can say that in all my motorcycles one plug worked in all weather related temperatures.
    The specific plug of choice depended on the specific motorcycle though.
  14. AussieSteve

    AussieSteve Active Member

    I agree with Gearnut. The B6HS is slightly colder. If I were you, I'd stick with it. It's the most suited to these engines.
    You could possibly use a B5HS in Winter, but it wouldn't make any real noticeable difference except that it might burn a little cleaner in cold conditions.
  15. geebt48cc

    geebt48cc Member

    RUNS very good, but?

    I finally got this 48cc Shyhawk running great, but when I did a plug chop, it really looks like it might be running to lean? The only reason I'm typing about this is because I don't want to hurt motor.

    The plug is dry, very light tan (One very small area, I think I even see white). It's on the second notch............Do you think I should take it down another notch to third, or just enjoy it like it is on second?

    The only reason I ask, is because I don't want to prematurely hurt a good running situation? 25:1, 4 1/2 tanks, about 250 miles

    Last edited: Jul 15, 2010
  16. GearNut

    GearNut Active Member

    Yes, lower the clip one notch to raise the needle.
    A bit on the rich side is better for these engines. It provides more oil laden fuel to lubricate the cheap bearings used in these kits which need all the help they can get.
  17. geebt48cc

    geebt48cc Member

    VERY AMEN!!!!!!!!!!!!!!!!!!!!!!!~ You know what I was thinking? I bet it's just a matter of time till someone,somewhere makes a great quality 2/stroke HT!!!!~

    They'll "RULE THE ROOST!"~

    PS: But when, and only when you get these little china dreams get settled and going well, they hold there own for that BIG amount of money.