Compression Release

[Zomby Builder]

Does anybody have a compression release that DOES NOT LEAK????

I have bought several of these. The stock ones are junk. Or do I just get shoddy ones? I had Quenton modify one, it leaked too. I modded it further & guess what -- It still leaked. I tried Bills, It leaks too.

This is not acceptable. Not a major leak, but still a leak. Have any of you had success in stopping this annoying problem or is this the way it will always be????????????

 

[Zomby Builder]

27 views & not one response

Does this mean that you all live with this problem? WTF!! One response would be good.....

 

[whizzer48]

Do you have a gasket for it?
If you talking about oil drip I use Gasgacinch for vw engine and any gasket.
It help the seal out where the seal can't do it job.
It like water down contact cement easy to clean up. Just wait a little to dry little and then put it on. Or do it went and have a rag ready to clean. Silcone in this case would be too thick. Most autopart store have it.



http://www.mamotorworks.com/acvw-air-cooled-vw-gasket-sealer-gasgacinch-1-129-10562.html

 

[Zomby Builder]

It's not leaking from the gasket. From the seal (or lack of) between the lever & spring...





Here is Quentons fix...... My smaller O-ring mod.. No working - Still leaking around the spring. Not sealing. Bill Greens leaks the same way. Stock whizzer part pours oil from HERE. This has got to be a common problem.. What is it?

O-ring ??????

 

[Fabian]

I've been screaming out for someone to install a compression release valve in the cylinder head of the Chinese 2-stroke bicycle engines, especially when used with the SBP Shift kit

Below is a commonly used compression release valve used in many chainsaws.
They are very compact, work with perfect reliability; don't leak and just do what they're designed to do.

Fabian

 

[james65]

I've been screaming out for someone to install a compression release valve in the cylinder head of the Chinese 2-stroke bicycle engines, especially when used with the SBP Shift kit

Below is a commonly used compression release valve used in many chainsaws.
They are very compact, work with perfect reliability; don't leak and just do what they're designed to do.

Fabian

Do you have to manualy depress the blue button to operate that valve ?

 

[Fabian]

Yes, you just push on the blue button and when the engine fires, cylinder pressure pops it back out.

Almost every chainsaw uses them these days, and every one of my chainsaws has a decompression release button.
I've never had one fail - "ever"

Fabian

 

[whizzer48]

If the oil just flood/ roll down the plate if it was me, I would try welding a halfmoon weld around the top. It may act like a house roof.

I don't think a resign it worth it. If you running a pvc valve can it be make the blowby going out the o ring?

 

[whizzer48]

Here a good picture what is under the spring.

 

[Quenton Guenther]

Hi Zomby,

Installing the "O" ring normally stops the leak, however if you have exessive crankcase pressure the "O" ring won't stop the flow of oil.

The best method so far is to remove the lever, remove the cam pin, and machine a ledge to allow the "O" ring to rest in the groove [between the cam and plate]. If you just install the "O" ring over the pin it won't stay against the cover to make a good seal.

Using a fresh bore and a cam ground piston [stock new edition Whizzer pistons are NOT cam ground] normally drops the crankcase pressure right away. Not sure why you motor didn't drop the pressure if the bore is correct and you used a cam ground piston.

The reason most Whizzer motors have high crankcase pressure is due to the piston & rings not sealing and allows blow-by into the crankcase. The majority of the Whizzer motors will settle down by the time 500 miles has been logged on the motor. Another cause is the breather system, and installing a small tube inside the tappet area will aid in reducing the amount of oil in the chamber. Insert tube in hole at the bottom of the NE cylinder and make the tube long enough to stop approx 1/8" from the top of the chamber. Drill 2 small holes at the base of the tube to allow the oil to drain back into the crankcase. The tube should be 1 1/2" long and the center hole should be 5/16". In order to press fit the tube into the hole at the base of the tappet area it needs to be .475" O.D.

See attachments



As far as the suggested use of the automatic compression release, Whizzer already installed the device on all the late model NE-Rs and Ambassadors and they leak compression badly and must be replaced with a 10 MM fine thread bolt.

Using the compression release on a 2 stroke was used in the early 70s on the race track before anyone figured out the open release at high RPMs removed all the oil from the cylinder. I watched hundreds of race bikes blow up when the release was used at the end of the straight to slow the bike for corner entry. It is amazing how quickly a 2 stroke will lock when the oil is removed from the piston/cylinder at 8000 RPMs.

Have fun,