Whizzer with no top end

GoldenMotor.com

Scootmeister

Member
Mar 15, 2011
243
5
16
North Carolina
Has anyone re-jetted an 18mm carb on a WC-1 after upgrading the jug and removing restrictors? After dialing in the fuel/air mixture the engine starts immediately and runs great getting up to 35 or 36 mph at 3/4 throttle before falling on its face for the remaining 1/4. Debbie at Whizzer USA tells me the 18mm came standard with a #80 main jet but I don't know if I should go down to a 78 or up to an 82. I know the drill for riding a mile with the throttle full open and checking the plug, but I'm sure someone has already dialed in an 18mm and could share their experience. Also, how difficult is it to change the fork seals on one of these? Mine started leaking at 200 miles!
 

Fossil

New Member
Mar 15, 2008
228
2
0
Guthriesville Pa
A guess on my part would be to go up to an 82. I say this because you removed the restrictions in the intake so you are getting more air. My only concern is I only have experience with the NE5 22mm carb. I updated and modified my 2000 WC-1 but I did not reuse the 18mm carb. I am using an 84 or 86 jet (I forget now) but my engine is highly modified. Is the chrome on the exhaust pipe right at the head turning dark blue? If so you are running lean and hot so an larger jet size would be in order.
Good luck.

Jim
 
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Scootmeister

Member
Mar 15, 2011
243
5
16
North Carolina
.wee.Thanks, Jim. My engine has a milled head, re-worked NE jug, progressive valve springs, copper gasket, and aluminum carb spacer. I'm not sure if enlarged valves were installed. I checked the exhaust and it isn't blue. Maybe a 22m carb is in order, but if I'm already getting 35 mph and could bump that to 45 with proper jetting, I'd be satisfied. If I convert the bike to hydraulic disc brakes to better handle the higher speeds, a 22mm carb might be in order. I have 203mm discs on my motorized bike and it stops on a dime. If I decide to go to the next level, where can I get a 22mm carb and how much do they cost? Thanks for the tips.
 

Fossil

New Member
Mar 15, 2008
228
2
0
Guthriesville Pa
You can find them on Ebay but they may or may not work correctly for you. Quenton may have one. He is a member here and I'm sure he will chime in. You can also PM him and ask if he has anymore. I tried a 26mm carb for a while and it ran great but was very hard to start. I used a 104 jet in that carb.The 22mm carb has been the best all around solution for me. As far as upgrades to the brakes I changed the wheels to Worksman drum brake wheels with 11ga spokes. These drum brakes are very good once they are broken in. I have a steep driveway and they will put be over the handle bars if I'm not careful. The hard thing about the rear drum brake is the sheave mounted correctly to the spokes.
 

Attachments

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All NE cylinder have a larger intake valve [24 MM].

The camshaft MUST be advanced one tooth, otherwise the motor is way too rich.

The stock carburetor will work best if the camshaft is the WC-1 stock version.

The top end speed is controlled by the main jet, and most often the jet is too large, not too small.

Look at the sparkplug, if it is black, and you have been riding at WOT for a short period of time the jet is too large. If you ride at WOT for several miles, then check the plug and it is white, the jetting is too lean [small]. You are looking for a tan or brown color after running at WOT for several miles.

You should be able to reach 45 MPH if the motor is tuned correctly. The lifter clearance should also be checked........007" intake, and .009" exhaust on your setup.

Test the bike with the intake breather removed, as many of the early motors ended up with large amounts of oil in the breather element from the oil vent hose. If the breather is obstructed it will act as the choke is slightly closed [will kill top end quickly]. Also try removing the muffle insert and check the results, as the earlier insert is very restrictive, and mostly effects the top end RPM.

The correct 22 MM carburetor is very expensive [$130.00], however it is setup correctly for the Whizzer motor with the correct slide, needle, pilot, and main jet, whereas others are almost impossible to make work correctly. I doubt you will need the 22 MM carburetor unless you upgrade the camshaft & exhaust system.

Have fun,
 

dmb

Active Member
Dec 4, 2010
1,354
3
36
lakewood ca
change your fork oil to dot3 brake fluid to swell the seals. then change back if you need heavyer oil or leave it if you want. warning it eats paint!
 

Scootmeister

Member
Mar 15, 2011
243
5
16
North Carolina
Good idea, Dennis, but I'm reluctant because the oil is running down the fork tubes and the DOT could wipe out my paint. I'm afraid my seals are cracked because my dust covers are. I'm thinking they are probably the same rubber. I'm also thinking If the seals are o-rings I could simply replace with standard sized neopreme. If they aren't 0-rings I will try to acquire from Whizzer USA.
 

Scootmeister

Member
Mar 15, 2011
243
5
16
North Carolina
Thanks, Quenton. I checked the plug and its black with soot. The air filter is clean because I disconnected the vent tube and ran it down below the engine. Guess I need a 76 or 78 jet. Also, I'm using NAPA 40 wt oil and though it doesn't blow out the vent hose, it seems to thin out quickly. I picked up a quart of Castrol 40 wt and am thinking about replacing the NAPA. Does the brand of oil make that much difference in your experience?