Whizzer valve lap tools & techniques

Discussion in 'Whizzer Motorized Bicycles' started by Traveler, Aug 3, 2009.

  1. Traveler

    Traveler Member

    What is a good kit to buy to lap the valves in a Whizzer H engine? The valves are pretty small, so I am thinking it may take some special equipment.
     

  2. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Traveler,
    You can purchase a tool at most auto parts stores [NAPA, etc] to lap the valves in. It has a suction cup on both ends [large & small].

    If the valve seats need to be cut it will be expensive because the tools needed aren't cheap. The tools are made by Neway.

    Have fun,
     
  3. Traveler

    Traveler Member

    Thanks. I didn't think the suction cups would be small enough.
    There is a Nappa close buy. I'll check it out.
     
  4. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    If you can't locate the correct suction cup size, just attach a pair of long nose vicegrip pliers to the bottom of the stem and push downward with your finger as you twist the pliers. If you need pictures of this method send me a request via email quincy163@yahoo.com


    Have fun,
     
  5. Traveler

    Traveler Member

    Pretty ingenious Quenton. Thanks.
     
  6. Traveler

    Traveler Member

    I have the tools to lap the valves on my Whizzer H engine. I have a "Whizzer Service Facts" book. It has no info that I can find for the steps in lapping the valves. I am mainly interested in the best way of getting the valve springs loose. My book shows removing the cylinder. I know how the lapping tool works. I have the head removed, and am ready to remove the valve cover. I would like to do it without removing the cylinder if possible. Can anyone outline the easiest and safest steps? (for the engine) Thanks for any info.
     
  7. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Traveler,

    I think trying to lap the valves with the cylinder on the motor would be very difficult to do. I place the cylinder on my work bench with the valve heads against the bench [cylinder upside down]. I then use a large screwdriver to press down on the washer until the "C" clip is easily removed. I simply reverse the proceedure when I re-install the "C" clip after the valve work.

    If you remove the "C" clip with the cylinder intact it might be next to impossible to re-install without someone holding the valves in place in the process.

    After I cut the valve seats or lap the valves I wash the cylinder with water to remove the lapping material and of the metal cut from the seats, which would be hard to do correctly if the cylinder was still attached.

    Let us know if you figure a way to do without cylinder removal.

    Have fun,
     
  8. Traveler

    Traveler Member

    Thanks Quenton. That's the method shown in the book. Just wanted to find out if there was an easier way. I probably need to try and find out what size rings I may need anyway.
     
  9. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Traveler,
    The vintage Whizzer company actually had a tool to remove the "C" clips and the part number was SPT-2223 and called a spring depressor. It is simply a peice of tubing with a door cut out to allow access to the "C" clip, and you had to use long nose pliers to pull the "C" clip out. I just normally use a large screwdriver on the rear of the retainer washer and push the front of the washer with my finger to keep the washer from binding on the valve stem while it is being "depressed". Once the retaining washer is lower than the slot in the valve stem the "C" clip can normally be pushed aside easily. The trick is to use a LARGE screwdriver, because it won't slip off the edge of the retaining washer as easily.

    To me removing & re-installing the valves, springs, washers, & clips is the easiest part of doing the "valve job" on a Whizzer. However I have worked on hundreds of cylinders, so the repetition might make it seems easier.

    On very common mistake I continue to see is the "C" clip installed upside down. The flat edge of the clip is located away from the washer. If installed correctly the rounded edge sets inside the retaining washer because the washer has a rounded area that fits the "C" clip exactly. If installed upside down the "C" clip will rock and widen the slot [groove] in the valve stem and cause extra wear on the "C" clip. About 75% of all the motors I work on have the clips installed wrong.

    I have a bunch of heavy duty [high performance] valve springs to fit the motor if needed.

    Have fun
     
  10. Traveler

    Traveler Member

    Thanks Quenton. I think I will pull the cylindar, rod and piston so I can do it right. I need to look at the rings anyway.

    I have a digital calliper. What measurements do I have to take to determine the right replacement rings?

    As always, thanks for your help. It is appreciated a lot.
     
  11. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Traveler,

    The clearance will depend on which version of the Whizzer piston used in your motor. Most versions of the piston will need .003" to .004" skirt to cylinder wall clearance. The ring gap on new rings will be correct if the piston to cylinder clearance is correct.

    When checking the clearance be sure to measure the piston below the wrist pin because the vintage pistons are cam ground.

    Unless you need to check the rod bearings I wouldn't remove the rod in the process if avoidable.

    Have fun,
     
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