Compression Release

[Brent Merkley]

Here is what I did

Hi zomby
I had been frustrated by the same problem. I fixed the problem 100%. To solve this problem completely, the crank case pressure needs to be vented much better. The amount of oil I have seen spit out of the cover is a joke, thanks to such great engineering by the factory. This is what I did to solve the crank case pressure problem. I disasembled the motor completely except for the crank rod assembly, I milled out the interior dividers in the labyrinth in two of the case halves. There are two places where gas can vent into the labryrinth pocket one is for the gass and one is for oil to drain back into the bottom of the case. I opened thse two holes to about 1/4 inch.dia. When I reassembled the case halves I stuffed the now open pockets with copper plated steel scrub pad material. Oil collects better on this material then on the cast in labyrinth. My compression release cover has an enlarged hole for a bit of 3/8 brass pipe with a hose that goes to my homemade breather. The breather is made much as Quenton recomended except that my breather attaches to the case to allow gasses to vent from the modified crankcase breather (labyrinth) system as well as the hose from the compression cover.

To fix the leaking at the compression cover I drilled out the shaft where the lever is crimped or stamped onto the cam shaft, drilled and threaded a hole so that a small allen bolt& washer could be used to reattach the lever. I reamed a bit of brass tubing to fit over the shaft with about .002 clearance, then I reamed the cover plate to the size of the brass tube and pressed it in with some sleeve retainer compound. Also I chucked the cam in my lathe and turned a small 1/4 radius around the back side so an o ring would have a better compression fit to the back side of the cover. The whole assembly works smoothly and has no play at all, the O ring has a nice seat and best of all it dosent leak, ask my wife she lets me park my Whizzer in our living room.

Best of luck
Brent Merkley

 

[Zomby Builder]

Really Brent - you get to park in your living room.. Some guys have all the luck. I'm lucky that I don't have to sleep in the garage sometimes.

I discovered something that I did out of sequence. The cover that I sent Quenton already had the lever welded. So he had no chance of taking the play out of that cam lever connection. I had a new one in my parts pile so I took it apart, machined a bevel on the interface so an o-ring would seat between the cam & the cover then I put a washer on the other side of the cover under the lever to take out the play. Then clamped the whole assembly together and welded the lever to the shaft so there was no play whatsoever. This worked like a charm.

After it cooled I put the o-ring on & attached the spring. Not leaking at all now.

The stock assembly is very deceiving because the spring puts tension on the cam & lever connection hiding the play between the parts. You have to take it apart & reassemble it without the spring to see how much play there really is. (There is a lot) Oil seeps through there very easily.

Sorry that I didn't take pics of the steps now, but I didn't know it would work so well.

I also made an oil collector with PCV valve similar to what a lot of you have modeled out of PVC except I just used Gates rubber hose & Chore Boy copper scrub. Same general idea just filled the rubber tubing with the Chore Boy & clamped the PCV valve to the end.

 

[Brent Merkley]

Good fix

Hi zomby
Always more then one way to skin a cat. Glad you have a bike that stays clean and full of oil. I also drilled a pocket hole in my drain plug and installed a magnet, cant be too safe!!
Cheers
Brent

 

[augidog]

27 views & not one response

guilty..but i always look at Zomby-posts...couldn't help so i just watched...looks like problem-solved

 

[Quenton Guenther]

It is possible to remove the exessive play between the pin and the hole in the cover by knurling the pin for a tighter fit, but still needs the "O' ring to make the best seal possible.

BTW the pressure will drop when the motor breaks-in more. It can take up to 500 miles before the break-in process is complete.

Have fun,

 

[Zomby Builder]

Whizzer design engineers???

Dear Mr. Whizzer:

I was just tallying all the $$ that I spent on correcting this obvious (now) flaw in design of this part.

I bought 3 at 18.85 each plus shipping from Whizzer USA.

I sent one to Quenton (he did not charge me for the o-ring modification) but I had already welded the lever to the shaft without taking out the play so it still leaked a little.

I spent at least 20 hours of my time trying on & taking off the covers on both motors.

I stripped out the threads on my previous motor from all the on - off & had to use longer bolts.

My new motor came with a stock one (although welded by Bill) (no o-ring) I installed the o-ring, but still had the play in the shaft so it still leaked.

Finally got one to work without leaking. After failing & ruining two new ones.

I didn't mention that the stock lever is very cheaply press fit onto the shaft, I discovered this the hard way when the first one I had came apart on the road. I thought I had fixed it by welding it together.

How long has Whizzer been using this design on new bikes & selling this part? If they were Toyota or GM there would have been a massive recall. Oh how the California lawyers would get rich on this class action......................

Sincerely,
Zomby

 

[Zomby Builder]

It is possible to remove the exessive play between the pin and the hole in the cover by knurling the pin for a tighter fit, but still needs the "O' ring to make the best seal possible.

BTW the pressure will drop when the motor breaks-in more. It can take up to 500 miles before the break-in process is complete.

Have fun,

Quenton you should sell these fully modified for around 75.00 make a little $$ & save future owners the frustration. I believe there are lots of folks like myself that have this same trouble.