Expecting more ............

Discussion in 'Performance Mods' started by geebt48cc, Nov 4, 2010.

  1. geebt48cc

    geebt48cc Member

    Hey all,

    I just got back from nice trip and I didn't quite have as much power as normal? See, the other day I port matched the Intake/Exhaust and thought for sure that there would be at least a little more power. So, when I put SBP expaintion chamber back together the small rubber pieces just fell apart.

    Well, wonder if sense 1 of the two pieces wheren't used on this last trip if hurt my performance, causing problem......

    .......any ideas

    Glen
     

  2. Pablo

    Pablo Motored Bikes Sponsor

    If you really opened your ports up to match, this probably changed your previous fuel/air requirement. What size jet do you have? How does your plug look?

    Missing the silicone seals won't change the running too much, but it will leak. You can use exhaust pipe sealer or get new seals. We will have black in the future.
     
  3. geebt48cc

    geebt48cc Member

    Yes, I just went to match the ports to the jug. The intake was very much off. Jug was square, and intake was round, so I matched to jug. The plug was a very nice tan.....Now after porting, it's trying to turn a darker gray in color.

    TY
     
  4. Pablo

    Pablo Motored Bikes Sponsor

    Hmm...maybe a little rich now, but that shouldn't effect power too much.
     
  5. geebt48cc

    geebt48cc Member

    Hope you're well Pablo.

    So, do you think I should jump up on needle. That will be the last adjustment. Uno, also, it's the original HT market speed carb w/jets. I wonder if I could drill the high speed jet? Isn't the needle adjustment onl for lows and muds, or just get next size up?

    Whats the size of bit?

    TY
     
  6. Pablo

    Pablo Motored Bikes Sponsor

    But if you drill it out it will be richer, or do you plan on filling and drilling?

    You could try dropping the needle but I assume your power is lacking at WFO?
     
  7. Pablo

    Pablo Motored Bikes Sponsor

    I would try a .66 or .68 jet.
     
  8. geebt48cc

    geebt48cc Member

    The original size jet for stock Skyhawk 48cc 10/2009. Total miles only 300.

    It has to run with choke half-way on. I've checked so well for any leaks? In any other case of porting intake (that attaches to jug) , would you need to change jets? Could there just be a leak? Sealed intake gasket with o-ring on carb like it was before.

    TY
     
  9. Ghost0

    Ghost0 Guest

    If it runs better with the choke on then it is too lean. This is usually due to an intake leak. Try raising the needle by lowering the clip after you have checked and confirmed there are no air leaks. If it gets better after raising the needle then maybe look for a larger jet rather than a smaller one but ensure there are no leaks first.
     
  10. HeadSmess

    HeadSmess Well-Known Member

    air leak, gunk in the jet, or just too lean now.

    i will point out right now that when the gasket goes on any sort of EXPANSION/TUNED PIPE...performance drops drastically. the pipe generates high pressures that are only contained by gaskets! any leaks or holes arent appreciated!

    so rubber things breaking would be half your prob. id say all the prob if it wasnt for that choke bit...

    always a dead giveaway when my gaskets gone... i cant get much over 35kmh...
     
    Last edited: Nov 5, 2010
  11. Pablo

    Pablo Motored Bikes Sponsor


    Dude - you should have said this at first. You have an air leak or somehow a fuel restriction problem. Fix it and get back with us. Make sure you are using a real fuel filter, a good fuel valve and that your carb parts are spotless. You said it was running fine before, or so I thought. Something so gross, yeah don't go messing with jet sizes until the obvious problems are fixed.
     
  12. geebt48cc

    geebt48cc Member

    No, was running great with chocolate colored plug. See, after porting (intakes to match) runs just a we bit slower with a grayish colored plug.

    See, the whole point of matching the ports was to at least gain alittle bit more. Didn't mean to bother you guys with this stuff, just wanted to see if there was something obvious that I'm overlooking.

    thanks............
     
    Last edited: Nov 5, 2010
  13. Pablo

    Pablo Motored Bikes Sponsor

    Not bothering anyone at all, just logically your bike can't possibly be running all that great if you have to keep the choke half closed to make it run.

    As they say, fix the easy stuff first. Here's a series of questions:

    1) Is your head gasket leaking?
    2) Are the nuts properly torqued?
    3) What are you using for an intake gasket? Is it whole and well sealed?
    4) Is the carb well seated against the o-ring and no exposed gaps? (I used an o-ring AND blue RTV)
    5) Are you using the in tank screen?
    6) Which fuel valve are you using?
    7) Does fuel flow freely and quickly?
    8) Is the float set correctly?
    9) Is there any grap in the float valve or main jet?
    10) Does your needle have a nice slow but good taper?
     
  14. geebt48cc

    geebt48cc Member

    1) Is your head gasket leaking? Original (300 miles) zero leaks
    2) Are the nuts properly torqued? Yes, 12lbs each
    3) What are you using for an intake gasket? Is it whole and well sealed? Original
    4) Is the carb well seated against the o-ring and no exposed gaps? (I used an o-ring AND blue RTV) Same here
    5) Are you using the in tank screen? Yes, never had any problem, but can check
    6) Which fuel valve are you using? Same as what SBP has. Original from GASBIKE on Skyhawk GT2 new of 12/o9/2009
    7) Does fuel flow freely and quickly? It looks very free flowing and full
    8) Is the float set correctly?....21m from base to gasket
    9) Is there any grap in the float valve or main jet? (?) made sure everything was tight
    10) Does your needle have a nice slow but good taper? Yes, now, and been on second from lean on top of needle
    __________________
     
    Last edited: Nov 5, 2010
  15. Pablo

    Pablo Motored Bikes Sponsor

    5) take tank screen out and use inline filter
    6) Don't understand. You have our valve or Gasbike stock valve?
    9) I meant to type **** (krap) or dirt stuck in the jet or the valve the fills the bowl?
    10) The needle itself - you added taper to it??

    11) What fuel/oil mix?
    12) Have you changed the ratio?
    13) How fresh is the fuel?

    Again - there is a reason for the running with 1/3 choke....
     
  16. geebt48cc

    geebt48cc Member

    5) take tank screen out and use inline filter
    6) Don't understand. You have our valve or Gasbike stock valve?
    9) I meant to type **** (krap) or dirt stuck in the jet or the valve the fills the bowl?
    10) The needle itself - you added taper to it??

    11) What fuel/oil mix? just switched from 25:1, to 32:1 after 3 1/2 tanks or 280 miles
    12) Have you changed the ratio? Never
    13) How fresh is the fuel? 5 weeks

    Again - there is a reason for the running with 1/3 choke...

    Hey, thanks for your time here!~:) Glen
     
  17. geebt48cc

    geebt48cc Member

    I have the GASBIKE stock valve..............Which never has leaked but does still have stock screen. I very much cleaned tank before I installed.

    I've never done anything to needle .......

    When I made sure float was 21m....I checked about 5 months ago, and everything clean in bowl + jets
     
    Last edited: Nov 5, 2010
  18. Pablo

    Pablo Motored Bikes Sponsor

    I advise getting rid of tank screen and getting a inline filter - and sometimes the stock valves just suck.

    You need to make sure that the needle has a nice gentle taper - hard to describe but more smooth than a round toothpick.

    Jets could easily be loaded with stuff from after the tank filter.
     
  19. geebt48cc

    geebt48cc Member

    Ok, appreciate that information. I have always had a inline filter from day one, but I'll get a new one anyway with checking and cleaning jets. Uno, wanted to ask you if thoughs screens really get that bad, even if the tank was cleaned to the max before any gas was put in? Total gas that has been used in tank is 3 1/2 total sense engine came out of box.

    So, as far as the needle is concerned, should I just take the needle out and lightly sand (taper) some to shape? Taper to blunt end , right?
     
    Last edited: Nov 5, 2010
  20. Pablo

    Pablo Motored Bikes Sponsor

    Oh if you have an inline filter already, then just lose the tank one. No need. Eliminate that variable.

    No need to shape your needle if it is already shaped in a nice taper. All I'm asking you to do is check it.....and I know from experience if it's not tapered, it will run like dog doo-doo unless you choke it....
     
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