I need help with Whizzer clutch slipping

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,615
421
83
Los Angeles, CA.
Hey fellas... I'm working on a Whizzer for a friend & the clutch is slipping really bad!!

I've tightened all the belts, but the problem seems to be in the clutch pads aren't grabbing enough.
I sand papered the pad & bell surfaces, & even removed the springs that pull the three clutch pads in... This all helped a little, but the bike is still winding at really high RPMs & barely moving. :(

Any ideas? Are there any heavier pads I can buy for it?

I included some pics of the clutch... Thanks in advance! :)
whizzer1.jpg
whizzer1.jpg
whizzer2.jpg
whizzer3.jpg
 

Tony01

Well-Known Member
Nov 28, 2012
1,388
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sf bay area
I don’t remember who sells it, but there is a max-torque based jackshaft out there for these. There is a problem in that the spacing gets messed up because whizzers usually had a manual clutch with the JS pulleys right next to each other. I’m trying to fix the issue on my buddies whizzer with the max-torque auto clutch. Probably going to move the motor about a half inch to the left.

also you may want to run a cogged type v-belt for the front due to the tiny pulley. Believe it is the AX style belt.

Can’t really help with that stock clutch though
 
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wrench

Member
Aug 20, 2019
48
15
8
So Cal
Your springs might be too strong Contact Paul @ www.whizzercruzzerparts.com to buy the correct springs.
The clutch wont work with no springs

The clutch looks new and needs to be burned in You will notice only a fraction of the pad is making contact to the drum you will need to keep sanding off the pad contact black burned area until you get at least 1/2 pad to drum contact. When ya get the clutch to engage ride around the neighborhood revving the engine, Yes the clutch will slip but you'll be burning it in.
To speed up the burn in process park the front wheel against the wall and burn in the clutch until ya get full pad to drum contact. Whizzer USA called this the Burn in period
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,615
421
83
Los Angeles, CA.
Your springs might be too strong Contact Paul @ www.whizzercruzzerparts.com to buy the correct springs.
The clutch wont work with no springs

The clutch looks new and needs to be burned in You will notice only a fraction of the pad is making contact to the drum you will need to keep sanding off the pad contact black burned area until you get at least 1/2 pad to drum contact. When ya get the clutch to engage ride around the neighborhood revving the engine, Yes the clutch will slip but you'll be burning it in.
To speed up the burn in process park the front wheel against the wall and burn in the clutch until ya get full pad to drum contact. Whizzer USA called this the Burn in period

That's pretty much what I figured out on my own.

I noticed that the clutch was grabbing a little more every time I rode it... so I totally removed the springs & sanded the pads to match the clutch bell.

It actually rides really nice now without the springs. (^)
 

wrench

Member
Aug 20, 2019
48
15
8
So Cal
That's pretty much what I figured out on my own.

I noticed that the clutch was grabbing a little more every time I rode it... so I totally removed the springs & sanded the pads to match the clutch bell.

It actually rides really nice now without the springs. (^)
Now that ya got the clutch to engage better put the springs back in.
You'll have better performance with clutch engagement at higher RPMs.

Whizzer USA and Cruzzer have used different strength springs over the years not sure what springs ya got.

I use the springs Cruzzer uses now and I also lighten my clutch shoes to get the clutch RPM engagement I like.

I thought I remembered trying the clutch without springs once. I guess I didn't like the way it engaged at low RPMs. Excuse me for saying it wouldn't work.

Pic of a lightened clutch shoe and the Cruzzer spring
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I also modified the clutch to spin better but will require some explaining.
pic of the cover plate and Bronze bushings.
This set up requires shortening the Whizzer Clutch Shaft to 35mm
Also requires making sure the spacer in the clutch shaft between the 6901 bearings is the correct length.
No slop and I get full pad coverage by the drum
DSCF7438.JPG
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DSCF7444 - Copy.JPG
DSCF7453.JPG


There is more than one way to Skin a KAT
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Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,615
421
83
Los Angeles, CA.
Thanks for the advice, but I originally posted this over a month ago asking for help.... I got ZERO help when I needed it!!

I solved the problem, & the bike is now back to it's owner (& running great without the springs). ;)

*edit* ... I like how the engine engages at low RPMs without the springs... It's very nice for 'cruising' around the beaches & streets.
 
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wrench

Member
Aug 20, 2019
48
15
8
So Cal
Thanks for the advice, but I originally posted this over a month ago asking for help.... I got ZERO help when I needed it!!

I solved the problem, & the bike is now back to it's owner (& running great without the springs). ;)

*edit* ... I like how the engine engages at low RPMs without the springs... It's very nice for 'cruising' around the beaches & streets.
Been busy on another site I'll try and check here more often
Always willing to share info to make these Whizzers run better.

I know the clutch can wear funny the way it's currently set up.
The retaining washer eats into the clutch face The clutch shaft wears into the retaining washer. The clutch drum only covers part of the shoe pad. My pictures are posted for others to notice who might be having an issue with their clutch
I've had my NE-5 for 15 years, Check out my odometer Miles.
Since this pic I now have almost 38,500 miles
ALOHA

Yes, It's kinda tricky taking a spedo pic going 50 mph
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DSCF8377.JPG
 
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wrench

Member
Aug 20, 2019
48
15
8
So Cal
Hey fellas... I'm working on a Whizzer for a friend & the clutch is slipping really bad!!

I've tightened all the belts, but the problem seems to be in the clutch pads aren't grabbing enough.
I sand papered the pad & bell surfaces, & even removed the springs that pull the three clutch pads in... This all helped a little, but the bike is still winding at really high RPMs & barely moving. :(

Any ideas? Are there any heavier pads I can buy for it?

I included some pics of the clutch... Thanks in advance! :) View attachment 105668 View attachment 105668 View attachment 105669 View attachment 105670
Actually I was kinda surprised to see this question from Venice Motor Bikes.
 
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wrench

Member
Aug 20, 2019
48
15
8
So Cal
If someone thinks they have fixed a slipping Whizzer Centrifugal clutch By removing the springs,
They haven't solved a problem they have just created Poor Clutch Performance

Fixing a centrifugal clutch from slipping by removing the springs is wrong.
Centrifugal clutch have springs for a reason.
1) Engine will idle smooth, Clutch pads not engaged (No load) Normal Idle speed is 1,200 RPMs
2) Clutch will engage at a certain engine RPM speed Usually 2,200 RPMs
3) Clutch engagement RPMs can be made higher or lower by using different strength springs.
4) Clutch springs greatly improve performance
5) Clutch springs Help with acceleration when coming out of corners by keeping the motor within the correct RPM range also helps with acceleration from a stop and greatly improves hill climbing capabilities.
There are more reasons to list of why springs are used but I think 5 is enough

The only reason not to use clutch springs with a Whizzer Centrifugal clutch is.
1) inexperience
 

MEASURE TWICE

Well-Known Member
Jul 13, 2010
2,429
518
113
CA
I just connected the picture about lightening the pads, guess for grabbing at a higher rpm. I have not really had any issue with clutch, but engine and clutch with no gearing to switch has limitations on trail riding. Thinking like 14% grade dirt fire roads, really could use 15hp.The parts I always clean after lube the bushing are on the bell inside and the part of the shoe that contacts. Sand with emory cloth and clean with acetone. Also a not very good belt sheave had a butt weld bump where the extruded sheave wrapped around. I took a dremel grinder and sand by hand, then no slipping except when going through small streams. I have 3.5 briggs with a max torque for my DIY, does well enough for a few trails and roads for OHV I like doing.
 

wrench

Member
Aug 20, 2019
48
15
8
So Cal
Here's few pics of the bike... it's a vintage Monark Whizzer with a modern engine View attachment 105908 View attachment 105909 View attachment 105910 View attachment 105911
Not sure why the builder thinks it's a good Idea to use the clutch arm mounting bolt as the motor mount. I would suggest to the builder to use the stock mount bolt location on the motor.
The clutch arm mounting bolt needs to be able to pivot with the clutch arm.
So no way the clutch arm mounting bolt should be used as a motor mount bolt
That means if ya tighten it down tight it prevents the clutch arm from moving
If ya make the bolt snug so the clutch arm will be able to move then the motor mount is loose


Also sure is a waist of having a 65W stator Should at least run a Vintage headlight and a tail light. That would compliment a nice build.

Do you know how many 2 stroke guys wish they had a 65w Stator to run lights off their motor?
 
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