Whizzer Carb Adjustment Screws

Discussion in 'Whizzer Motorized Bicycles' started by MoonKS, May 3, 2008.

  1. MoonKS

    MoonKS Member

    Hi everyone,

    I believe my Whizzer might be idling a bit high - I am looking at the adjustment screws on the carb and I am not sure what each one does...

    I have attached a picture of the carb on my NE5 - I labeled one screw A and one B. What is the purpose of each one - I turned A counterclockwise a bit and it brought the idle down a bit....

    I know one is for air mixture.... I am just trying to learn what each screw is responsible for and what the ramifications of adjusting them are (making too rich or too lean).

    Thanks in advance!



    Attached Files:

  2. MoonKS

    MoonKS Member

    And while I am on the subject - do I have to order the inline fuel filter for my NE5 from Whizzer or is there some alternative I can buy in my local autoparts store?

    My Whizzer has just over 300 miles on her and the fuel filter is full of little black specks....
  3. 22mm carb

    HI Moon, the "A" screw jacks the slide up and down via a ramp cut in the side of the slide, this is Idle Speed Adjustment.

    The smaller "B" screw is then an Idle Mixture Screw, which I beleive to be the air-bleed type, due to it being in the throat of the carb.

    This would mean, preset idle with the speed screw, refine the mixture, reset speed to desired, and then refine mixture, if needed.

  4. MoonKS

    MoonKS Member

    Thanks Mike!
  5. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi MoonKS,
    Mike is correct the air mixture adjustment screw is AIR on the 22 MM carburetor. Turning the idle mixture screw counter clockwise adds air [lean], normally the screw is 1 - 1/2 turns out. The best way to adjust the idle mixture screw is to start with a warm motor, adjust idle mixture for fastest idle and the adjust idle adjust screw to maintain an idle between 1200 and 2000 RPMs [don't lower idle to sound cool below 1200, because the motor is a "splash" system].
    The 26 MM carburetor is just the opposite on the idle mixture adjustment because it is FUEL [not air], and turning the screw counter clockwise adds fuel [rich], and the normal setting is 1 turn out. The adjustment on the 22 MM has less effect than the 26 MM carburetor.
    Have fun,
  6. MoonKS

    MoonKS Member

    Hi Quenton - do you mean 1 to 1.5 turns or 1/2 to 1 turn.

    And by turns do you mean a full 360 degrees or a 180 degrees?

    Sorry for my lack of understanding....


  7. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Matthew,
    Thanks for pointing out the error in my post. 1 and 1.5 turns out. One turn = 360 degrees.

    Have fun,
  8. MoonKS

    MoonKS Member

    Hi Quenton,

    Thanks for the information! I adjusted the screw appropriately - I replaced my fuel filter with a better quality line from a Go-Kart/Lawn Mower repair shop - I found a clear filter but it was 1/4" - but I got some nice clamps from the shop that clamp tightly and there are no leaks.

    Tuning my idle and air mixture - cleaning out the gas tank today - putting a new fuel filter on - putting the new Iridium plug in - she runs a lot nicer - surprising what some simple improvements and maintenance will accomplish!


  9. go-rebels

    go-rebels Member

    Thanks Quenton,

    How do I know if I have a 22mm or 26mm carb? Also, for reference, which way do I turn the idle adjust screw to increase RPM (CW or CCW?)
  10. Carb 101 continues

    Hi Go, well not much chance that you have a 26mm, it would be the 22mm as the 26's were pulled at Headquarters.

  11. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Go,
    Just finished the final quality control checks on hundreds of "mushroom" lifters, and will ship yours tomorrow. Maybe I go a little too far on quality control, but it is part of our company policy at EZ Motorbike to make sure we only offer the best. During my checks I actually found one lifter that was off by .002", but after more research I discovered it was the original I sent as a sample [I found it because I ended up with a odd number, as we ordered them in sets]. It looks our new vendor takes quality control seriously.
    I wouldn't spend any time adjusting the carburetor until you install the new lifters, because it will change slightly after the install. The lifters alter the performance in many ways including the idle settings. When you install the mushroom lifters please set the clearance on the intake at .006" and the exhaust at .008" [I set mine at .005" and .007"]because the new lifters are so precision. The new lifters increase the duration, lower the valve train stress, lower the weight, hold the valves wide open longer, but most importantly make the motor far more durable [bullet proof]. The mushroom lifters help all new edition Whizzer motors including a stock WC-1 because it reduces the "snap" and the lifter "rolls" over onto the camshaft ramp. Because of the lighter weight the new lifters also help reduce the "pounding" of the valve seats when the valves are returning to the closed position. Many have upgraded the WC-1 motors with the NE cylinder kit, but continued to use the stock .150" lift camshaft, the mushroom lifters will also enhance the performance in the lower and midrange of the converted motors.
    Converting to the mushroom lifters will help every version of the new edition motors, so it is a "win-win" upgrade.

    After the lifters are installed and the clearances set, warm the motor up for approx. 5 minuites [ride it, don't let it sit and idle]. With a warm motor adjust the air mixture screw for maximum idle speed, then turn inward [clockwise] about 1/16 of a turn to make the low speed mixture a little on the rich side. Remember the adjustment on the 22 MM carburetor controls air, not fuel, so turning it clockwise [just a tiny bit] makes the flow richer. The best place to start is to adjust the screw all the way in [careful, don't over tighten], the back out approx 1 and 1/2 turns as a starting point, then with a hot motor find the spot with the higest RPMs.

    I doubt you have a 26 MM carburetor because I purchased 99% of them in 2005. The 26 MM has the air mixture screw under the front of the carburetor and therefore adjusts fuel, not air.

    Happy New Year,
  12. go-rebels

    go-rebels Member

    Thanks Quenton!

    I look forward to tinkering with my new (22 mile bike). I picked it up Monday and it is cosmetically near perfect. I ran it once but it ran somewhat poorly, probably due to very old gasoline. I'll drain that and fire it up once more so I have a baseline as to how the thing runs 'stock'. The only things I've done so far is change the oil (10W-40 Mobile One) and replace a blown 5A fuse.

    The battery was dead and I recharged that too. How is the battery recharged?

    Thanks again!
  13. KilroyCD

    KilroyCD Active Member

    Go-rebels, I'd change that oil again. The Whizzer engine will usually purge itself of a multi-viscosity oil in short order. You'll find it getting blown out the breather. The specs are to use straight 40W oil in Whizzers.
  14. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Go,

    I think most of the fuses are 7 Amp, As stated in an earlier post by KilroyCD you should remove the oil and replace with straight 40 Wt. Another problem is using synt. oil, because it won't let the rings and cylinder mate together. I have tested the synt. oil and find is of no value on the Whizzer motor, in fact it will leave the crankcase faster through the crankcase vent system.
    If you are using the original gasoline I would drain it all and when putting fresh gasoline in the tank I would use some Gummout carburetor cleaner [mixed very heavy] for the next 2 tanks full.
    The charging system is somewhat "border line" and won't charge a dead battery while operating the lights. I use a small "trickle" charger to start with a fresh charge and the charging system can usually keep it up if fully charged. The charger I use is an old camcorder charger used to charge the 1.2 amp in a camcorder, but K-Mart & walmart usually stock a small charger.
    Have fun,
    Last edited: Jan 2, 2009
  15. go-rebels

    go-rebels Member

    Hmmm, the fuse that was blown was a 5A, so that is what I replaced it with. I will switch it out to a 7A.

    I'll also change the oil back over to straight 40W.

    A few years ago I purchased a "Battery Tender", one of the best trickle chargers on the market, and use it to keep my lawnmower battery fully charged when it's parked. I used it to charge the Whizzer Battery but time will tell if the charge holds.

    Anyway, back to the carb. If I take off the bowl to the carb, the quarter gallon of gas in the tank should drain right through the carb, right? Then I can spray the innards with Gumout, reassemble, fill with fresh gas (w/added Gumout) and be good to go, correct?
  16. Carb

    Hi Go, you can remove the float bowl, but usually cannot put it back on till the gaskey (o-ring) shrinks back down.

    Why not use the carb drain line, OR do it thru the fuel line at carb?

  17. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Go, Like Mike said, the O-ring will swell when the gas hits it. Either use a hair dryer to shrink it back to size or lay out in sunshine. Be sure to spray cleaner into all passages in the carburetor body, and also spray into main & pilot jet. Don't use pressurized air unless the float bowl is removed or you will crush the float.

    Have fun,
  18. go-rebels

    go-rebels Member

    Yes, I'll leave the bowl untouched. The last bowl I removed created a gasket that never shrunk back to proper size!

    I'll run gunout through the fuel line directly.

    Thanks again for all the help fellas!
  19. BonitaPanther

    BonitaPanther Member

    Hey Guys, all this makes sense, but on mine the Tach reads higher when the tire is off the ground and lower when I am sitting on it. Should the tire be up or should I be sitting on it when I make the adjustments.....
    Or does the fact that the RPM changes mean I have other issues?

    Last edited: May 1, 2009
  20. RdKryton

    RdKryton Active Member

    It is normal for the RPM's to be higher when the rear wheel is off the ground. I would make my settings when the RPM's are around 1000-1200. Remember to warm the motor all the way up before you change anything.