Whizzer intake restrictor plate questions.

[Zomby Builder]

Intake restrictor

What a difference this makes!!! It is a PIA to remove, but worth it...







This sleeve restricts the intake from 18 mm to 8mm.

I was however: able to use my very favorite tool; a 3 lb. sledge hammer!

 

[Quenton Guenther]

Smooth out the inside of the intake port if you want a little extra power. A few comments about the WC-1 cylinder might be important to mention now that the restrictor has been removed. The WC-1 motor doesn't do well when modified because of the increased cylinder tempature, sometimes in excess of 600 degrees. When the restrictor is removed the power is increased and with power comes heat. The fins on the NE cylinder were increased to deal with the extra heat, and the NE head is made differently to also lower the operating tempature. Whizzer owners tell me of 1999 models with over 6000 miles on their bikes, but the motor was "pure stock", and I have had owners with modified motors that stopped working correctly at about 500 miles. I myself made over a dozen WC-1 cylinders into scrap trying to make it do something it wasn't designed to do. While it is true I did get some really good average speeds [52 MPH], sadly the cylinders lasted under 500 miles. Actually it wasn't only the cylinder that dis-liked the heat, but the head also liked to warp to test the limits of the head gasket. Just remember the "vintage" heads must have suffered the same fate because there is a section in the "vintage" manual about re-surfacing the head, hum! funny how history repeats its self. Just for the record the WC-1 has a much longer intake port, smaller head bolts, and smaller intake valve than the NE cylinder.
Just remember to keep that WC-1 cylinder cool if possible, and is better to run the carburetor a little rich than lean. I did notice your cylinder was painted black, which in my opion & personal tests does help keep it cooler. You might also want to install a copper head gasket on the WC-1 to lengthen the lifspan. I think the copper head gaskets for the WC-1 are available at several places, but I have them if needed.
Hope this information is helpful,
Quenton

 

[Egor]

Qunton - On the WC1 cylinder did it have a sleeve or was it just Aluminum? How did they fail? piston stuck or galled liner! I used to build a lot of hot bikes and one of the things we had trouble with was the material the piston was made from, IE if they would swell or if they were stable. The cam grind on the piston was critical also, there is a science to the shape of a piston. You should be able to deal with the heat if it is correct, also retarded ignition will heat things up. Take a good Honda motorcycle piston and mike all the areas, you would be amazed. Then check an after-market part. Have fun, Dave

 

[Quenton Guenther]

Hi Dave, The WC-1 motor does have a metal cylinder sleeve, and the issues concerning the earlier motor are not piston related. When the WC-1 is over heated the aluminum cylinder expands faster than the valve seats, and the seats become loose. Over the last 8 years many have tried to cure the problem of loose seats on the WC-1 cylinder. I even paid a company in Ohio $1200.00 to eventually solve the valve seat issues, and many have tried "staking" the seats, replacing with oversize seats, different metal for the seats, using exterior set screws, etc. During the last efforts to remedy the valve seat problems the company in Ohio concluded the repair price to be $175.00 per cylinder [dealer cost], sadly it was a major waste of my money because the NE cylinder only retails for $184.75. And the NE cylinder has many upgrades to overcome any issues concerning heat & performance. Whizzer's NE cylinder is by far the best choice if anyone plans to extract additional power from the motor because of the larger head bolts, larger intake valve, shorter and larger I.D. intake port, larger cooling fins, redesigned head, etc. During my research concerning the WC-1 motor I found if the motor is left pure stock it worked as represented by Whizzer, but if modified it was almost sure to develope loose valve seats. Whizzer USA offers a complete kit to convert the earlier WC-1 motor to the NE top end. The kit even includes the cylinder, head, bolts, gaskets, piston, rings, exhaust manifold, and a really good set of instructions. It is also possible to convert the earlier motor by just replacing the cylinder, head, head bolts, gaskets, & exhaust manifold. The head on the NE has a different bolt pattern and isn't interchangeable, and requires a different exhaust manifold to clear the larger cylinder fins. Hope this information is helpful.
Quenton

 

[Egor]

OK, thanks for the info. I have seen a few WC1's for sale and wondered what the issues would be. that is not an easy fix, over the years I have had a few B&S engines with the same trouble, there was not a lot you could do, but what you explained. Honda casts the seats in the head so they lock in and are not removable. I had one engine a fellow had done with bronze seats, I cut the angles for him and fitted the valves, never saw him again, I only guess it worked. Have fun, Dave

 

[Quenton Guenther]

The NE cylinder is also cast with the seats. The WC-1 cut the block & press fit the seats. Several have replaced the seats [larger] on the NE cylinder without any problems, I guess the larger fins and different aluminum also aid in keeping the tempature down.
Quenton

 

[bill green]

there is a new manifold that go,s between head and carb , It drops carb temp and runs better aat all rpm.this is by whizzer and is cheep I have three at this time.BILL

 

[Quenton Guenther]

Hi Bill, Cut the manifold in half and you will see almost 500 additional RPMs on the top end. It is also possible to add 4 MPH on the top end by matching the manifold [19MM] to the intake port [18MM]. Best feature of the manifold is by moving the carburetor slightly to the rear it allows more clearance for the throttle cable in relationship to the frame.
Quenton

 

[bill green]

HI Quenton, I have already shortend manifold by 1/4 and matched the ports.also Im running the weber head you told me about. thank you for your help Bill green . vancouver Whizzer

 

[Quenton Guenther]

Hi Bill, Is it fast?
Whizzer OuterBanks
Quenton