Petcock Problemo!!

Maybe I missed it but what about the tank cap itself venting...checked/confirmed operating correctly?

Just a thought...

OMR

Old Man Rock wrote:

Maybe I missed it but what about the tank cap itself venting...checked/confirmed operating correctly?

Just a thought...

OMR

His bike works fine if the tank is in the prime position.

The Syringe should go back even in prime?

rsrcafe wrote:

The Syringe should go back even in prime?

Yes, as long as you are attaching the syringe to the vacuum port on the petcock. There should never be any airflow through the vacuum port on the petcock. If it did, then the bike would have a vacuum leak on the #4 cylinder (or which ever cylinder the vacuum petcock is connected to). Regardless of petcock position, there should be no air through the vacuum port. If there is, then something is not sealed properly.

Alright everyone, I solved the problem. Turns out that the petcock I have uses a long since obsolete(since it is notpictred in parts breakdow) diaphragm seal (top hat I mentioned in first post). I took it to my buddies dad (the tech who jetted the bike I might add)and it turns out that the seal was sticking in place even when the diaphragm opened due to ethanol in pump gas. The answer SUPER GLUE!!
The tech and I figured a dab of super glue on the male end of the daiphragm would hold the seal to it and would pull it open even if it got a little sticky from the gas/ethanol.
Go Figure...

Thanks for all your valuble input.

what would happen if you just ditched the whole vacuum setup and slapped on a new pingel? would that damage your carburetor if it was not vacuum type?

O.K ill try again ...where does this vacume line from the petcock connect to the carb and if it isnt connected will the bike still at least start and idle just whant to get mine running but for now dont have a gas tank can I hook up a temp tank without a vacume line just gravity...

I've never owned a bike with a vacuum petcock, but im pretty sure it doesn't connect to the carburetor. If I were you, i would do a little bit of research on how a vacuum type petcock works. But i cant imagine any harm being caused as long as gas is flowing to the carburetor. Install an inline filter so you can see if there is gas flow.

On many KZ's, it does in fact connect to the carburetor. usually carb #4. The carb has a port that goes directly to the intake manifold.

In other bikes I've seen the port on one fo the actual intake manifolds.

So it can be in one of several places, but you'll need someone who knows specifically on your bike.

wow, i learned something today. thanks! Sounds complicated though. I would much prefer a gravity fed system.

You will need to be certain that all four vacuum ports are blocked off when you try to start the engine with your temporary fuel supply. There are a couple of threads here about making an inexpensive tank to use for tuning purposes. If any vacuum ports are open, that cylinder will run extremely lean, causing the engine to be hard to start and to have an erratic idle and to run like goose poop.

The vacuum line goes from the petcock to a vacuum port on top of any one of your carbs.When the engine runs the vacuum from the carb opens the diaphragm in the petcock and fuel flows.When the engine is off,no vacuum,the diaphragm closes and no fuel should flow if everything is working like it should.As long as u have the stock petcock,u need a vacuum supply for it to work correctly. The Pingel petcocks lots of folks here use has no vacuum operated diaphragm and flows by gravity.Much simpler-but about 100 pesadas a pop.--worth it.bj