Whizzer intake restrictor plate questions.

Discussion in 'Whizzer Motorized Bicycles' started by del, Oct 8, 2007.

  1. del

    del Guest

    Howdy, Folks,

    I'm a new member here, so I'd guess that this topic has been covered. But going through the thousands of posts became a bit daunting.. So, I apologize for my ignorance in advance...

    I just bought a new Whizzer and, in the process of getting the needle-valve set at the right notch in the main jet, found myself pondering how to get rid of the restrictor at the input to the intake manifold. Has anyone done that? If so, how did you do it?

    I've read a few things here and there on the internet. But none of the folks elsewhere answered some fundamental problems...

    One person said to hog-out the gasket material with a hand drill, but said nothing about how to keep bits of gasket pieces out of the intake manifold. Another person said to remove the thick restrictor gasket, but said nothing about why you might want to isolate the carb from engine heat with an insulating gasket..

    Any ideas, or references to previous posts, would be appreciated.

    Last edited by a moderator: Oct 8, 2007

  2. New Whizzer intake

    Hi well altering the intake is illegal, but, if you don't care about that, or are going to ride "offroad" then which exact model do you have? Do you have the aluminum extension on the intake between carb and barrel?

  3. del

    del Guest

    Howdy, Mike,

    Am I wrong here? I thought the intake restrictor was there to reduce the top speed of the bike, so it would be a legal moped... The Whizzer seems to have too many CC's to call it a moped in Illinois, so I've licensed it as a motorcycle.
    So, I'm not convinced that opening up the intake is illegal for me. But I could be missing something...

    It's a 2007 NE 5. The trip between the carb and the engine goes:
    carb, plastic spacer, gasket, thick restrictor gasket, intake manifold..
    Nothing else...

    Does that help?


  4. gone_fishin

    gone_fishin Guest

    can i take a guess that the mod is a matter of emmissions, hence the legality issue?

    sorry to interrupt, but i'm really interested in learning more about these engines.
  5. bamabikeguy

    bamabikeguy Active Member

    Jack, my tinkering genius customer over in Eva, has 2 Whizzers bought at a closeout about 5-6 months ago.

    He called the California Whizzer distributor, found on a sticker placed somewhere on the bike, had a VERY informative conversation with the technical rep (Del- look in your private messages box).

    The lack of a transmission is the Whizzer claim (no matter that it is 136cc) to moped status. Don't know how they do it, but I guess it's the buyer responsibility/onus to especially obey city speed limits.
  6. restrictors

    Hi well I was just getting info for telling you how to do the job correctly, and as a CA dealer, I need to give you the old "illegal to tamper" song and dance!

    Take the black plastic, and use it to transfer the hole sizes to the flesh-colored piece. Then, I use a "uni-bit" tapered cone-shaped drill bit in my Dewalt cordless, and ream the hole from both sides to get it opened up, and reassemble in the exact same order as it came apart.

    Hope this helps,

  7. Egor

    Egor Guest

    Here in ca. the law is 2hp max, no shifting gears, no speed in excess of 28mph, and has to be able to be pedaled independent of the engine. That being said we just carved the center out of the restrictor spacer to the size of the intake tract and installed in proper order. Have fun, Dave
    PS: Keep it under 28mph, or you know what will happen.
  8. del

    del Guest

    Thanks for the great info, folks! It is much appreciated!

    It appears that, in spite of Federal "Guidelines", every state
    and town in the country seems to have their own laws. I
    won't go into details about my lengthy conversation with
    the Illinois DOT (though it is a bit humerous). But, no matter
    what I said about it being a moped, I was told that if it had 138cc's
    it _would_ go faster than a moped...

    So, in order to avoid being hassled by the local constabulary,
    I've licensed it as a motorcycle.

    I don't know what the top speed was when I first got it; I had
    other problems to solve. But once I got the main mixture set
    correctly it would go 30 MPH. For an old f**t like me, that
    seemed scary-fast enough.

    So, over the next few days, I'll contemplate the restrictor
    and decide how to attack it. Even though speed is not my goal,
    I don't like the idea of an engine that's not allowed to breathe free.


  9. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    It is very important that you don't remove the restrictor, because it is needed to help insolate the carburetor from the cylinder. If you open the hole to match the other spacers it should add a large amount of power in the mid to upper RPM levels.
    Last edited: Oct 11, 2007
  10. del

    del Guest

    That's what I thought, Quenton,

    The last thing you want is a carb that gets so hot the fuel boils in it!
    That would not be good....


  11. Egor

    Egor Guest

    The heat insulator should be in front of the restrictor, it is fiber with an O ring in it. If you registered it as MC then throw away the restrictor, here in Ca we are trying to keep the MP's happy and show them it is still there. Do the muffler next, pull out the baffle and trim it off, then replace. What will help the most is moving the timing plate, but you will need to make a small hole in the flywheel and tap it, move it ahead till you can just see the hole you are leaving, that is a safe starting point. All this stuff will help the engine Stay cool, and make it cruse effortlessly. Have fun Dave
    PS: Fill the tank with Alkie, remove the carb jets and get a high comp head, and do Bonneville. LOL You don't have to wear the same outfit.

    Attached Files:

  12. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Just a few quick comments concerning the restrictor & muffler insert. It is important to keep the restrictor plate in the intake passage to keep the carburetor cool. It is ok to open the restrictor to match the carburetor & intake port, just don't remove it entirely. The exhaust muffler insert on the current production NE motors should not be altered because It already designed for maximum flow and the necessary amount of back pressure. It is important to note that 3 different inserts have been used during the NE production. It is easy to identify the best unit by looking at the size of the hole in the insert. If the hole is approx. 1" leave it alone, if not purchase the current production insert from a Whizzer dealer [very cheap]. If the timing plate is moved 7/16" counter clockwise the timing will be 23 degrees BTDC [stock is 14 degrees BTDC]
  13. Timing Change

    Won't just rotating the cam gear clockwise 1 tooth do the same thing?
  14. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Zombie, Advancing the camshaft changes the timing concerning the valve open and closeing points, whereas advancing the ignition timing changes the point where the spark plugs fires. Although you are correct that both changes can alter the motors power band. Theory wise advancing the camshaft adds more torque on the lower end, as does advancing the ignition timing. But in real life the Whizzer motor produces more power at the top end by advancing the camshaft & timing, most likely because the motor needs more torque in general. It is also possible the timing [both camshaft & ignition] is retarded to meet EPA standards, and advancing them puts the motor closer to normal. Just for the record the vintage "H" & "J" motors fired at 30 degrees BTDC, and the later more powerful "300", "500", & "700" motors retarded the timing to 25 degrees BTDC.
  15. Stock changes

    I have a completely stock motor & an almost new cylinder just sitting in the garage waiting for the install. I plan on using it temporarily with a multiple speed rear end. (NuVinci Planetary) Just until I get the bugs out. Then it will get one of Qs heads & a bigger carb.

    The intake restrictor is easy to open, but I want to maximize the low end torque. Should I advance the cam gear and advance the timing plate? How do you know for sure that the motor is firing at 23 degrees BTDC? And will this be the best option for maxing the low end torque? Can someone go into more detail on exactly how to move the timing plate?
  16. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Zomby, Sorry I spelled your name wrong in an earlier post. If you want more low end torque just open the restrictor to 18MM. I think the 22 MM carburetor has a venturi 0f 17.9 MM. Advancing the ignition timing to 23 degrees BTDC won't help enough to notice. However it won't hurt to advance the timing if you just want to make changes to your motor for something to do. I can verify the change will end up at 23 degrees BTDC, by measuring the flywheel, divide by 360 to find the amount of advance by moving the trigger. If you advance more than 7/16" on many motors the fire will drop because the magnets are not aligned correctly for maximum transfer. On some motors advancing past 23 degrees will almost stop the motor [depending on which pick-up is used]. If you want to advance the timing without problems, simply remove the current trigger plate from the flywheel, lay the plate on the flywheel counter-clockwise until the plate covers 1/2 of the original hole, mark flywheel for new hole. Drill and tap to 5MM X.80, re-install the plate using the new hole and your motor will fire at 23 degrees BTDC. I have several motors [modified] that I aligned the magnets on the flywheel for maximum transfer , made a special adjustable plate to hold the ignition pick-up, and located the trigger plate to match the system and have been able to run as high as 40 degrees BTDC. So far 25 to 27 degrees BTDC works best for top end. Just to make your life a lot easier, if you deceide to move the trigger plate, it helps if you also move the plate slightly when removing the screw holding it to the flywheel. If you don't you may find it difficult to avoid damage to the screw during removal, in fact I have drilled out several before learning this "trick". I think almost all NE motors have the camshaft advance one tooth. Hope this information is helpful.
    Have fun,
    Last edited: Dec 21, 2007
  17. Egor

    Egor Guest

    Quenton - It is interesting you bring up the cam timing, in the 70's Chevrolet retarded the cam timing trying to meet the smog limits. We used to remove the front cover and just ignore the timing marks and set it to the original position, what a difference. You can slow the cam down on any flat head without getting near the piston as in a OHV engine. I used to always do my Briggs & Stratton go cart, I would never tell my friends and they could never figure out why my cart was so fast. I would always open the points as far as I could get away with too. I have too friends with Whizzers and both have a fiber insulator in front of the restrictor, just like a motorcycle, I have not seen one that is missing. On the two I did I hogged the restrictor all the way out, the reasion was, at full throttle the air was moving too slow to pull fuel up and it would lean out and start poping, you could back off on the throttle and it would be fine. Have fun Dave
  18. metal restrictor

    OK I just took the carb off & this motor has a metal plug in the intake that goes almost all the way to the valve.... More like a sleeve with a hole through it. #&%^*@$%% It won't come out. I even removed the intake valve to try to tap it out from the top. This might have to be drilled out. My other cylinder does not have this in there. Any Tricks to removing this sucker??

    Oh and to advance the cam which way do I allign the marks 1 tooth clockwise to the mark on the crank gear or counterclock to the crank gear?
  19. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Zomby, Sorry I thought you were working on a NE motor. The WC-1 motor has a sleeve pressed into the intake port. To remove it thread the hole with a 3/8 X 16 tap, find a deep well socket that will allow the removed sleeve to fit inside, next use a 3/8 X 16 bolt 6" long to fit through the socket and thread into the threaded sleeve. Locate the socket at the mouth of the port with the nut near the head of the bolt and the washer next insert the long bolt through the socket hole and thread into the sleeve, as you tighten the nut it will pull the sleeve into the socket. If this sounds confusing, let me know and I will try to explain it again, easy to do but hard to tell how. Turn the camshaft one tooth counter-clockwise, when finished the camshaft dot will be closer to the top of the motor.
    Last edited: Dec 21, 2007
  20. removed it

    I got it out by pounding the bejeevers out of it through the valve port. Wow no wonder this motor was such a dog.. That sleeve only allowed 8mm of flow through the intake. With it gone it now has 18. I would never have done this if I hadn't already seen one without this sleeve. It was pressed in there so hard I believe Mr. Whizzer didn't want this to EVER come out. Maybe this is why it is only 1.95 HP. I'd suggest don't try this at home cause I had to pound / Beat it into submission as MBM would say. You will do some damage if not properly equiped for this chore.
    Last edited by a moderator: Dec 21, 2007