Topic: Dunk the Petcock?

[Dr. Noisewater]

Hey guys I have a '75 and the petcock is completely gummed up. I can still move the lever, but no fluid is passing through this thing. As you probably know, the '75 sucks for petcocks. It can't be rebuilt and replacements are rare and around $100. I'll eventually splurge on a new one, but just for the sake of seeing if the bike will run is there a good way of cleaning it out so it will actually allow fuel to flow?

I thought about carb cleaner or something, but isn't there a gasket or something inside that could be destroyed by something that corrosive? I tried searching, but only found stuff relating to petcocks that can be rebuilt. Thanks for any ideas.

[chewbacca5000]

Hey guys I have a '75 and the petcock is completely gummed up. I can still move the lever, but no fluid is passing through this thing. As you probably know, the '75 sucks for petcocks. It can't be rebuilt and replacements are rare and around $100. I'll eventually splurge on a new one, but just for the sake of seeing if the bike will run is there a good way of cleaning it out so it will actually allow fuel to flow?

I normally take them apart and put them in my ultrasonic cleaner and they come back like new.  Does wonders on many parts.  Post a pic of the petcock and we can give a better answer.

I thought about carb cleaner or something, but isn't there a gasket or something inside that could be destroyed by something that corrosive? I tried searching, but only found stuff relating to petcocks that can be rebuilt. Thanks for any ideas.

[madScientist]

Take a 20oz water bottle...drill a hole in the cap...insert fuel hose and jbweld around the hose. Then drill a hole in the other end and put a screw in it.

Fill the water bottle with gas and put the other end of the hose on the carb. Undue the screw to allow air to pass and you now hae a small fuel tank.

[bjbuchanan]

Take it off and take the two Phillipa out that holds the thing together. Take out the rubber seal and clean the hell out of it. Don't use stuff that eats aluminum tho. For this kinda work, carbs too I prefer to use a leather/vinyl needle. Big and strong but flexible and pointed enough to get in there

[Dr. Noisewater]

So the 75's can be taken apart by those little phillips? Here's what I'm working with..

[goldarrow]

I just rebuilt mine yesterday.  You can take the internals out.

Undo the front two screws, be careful not to strip the heads, use pick tool to clean the two screw holes behind, put small drops on penetrant, let it sit for a little.  come back later and those two front screws should come out easy.

Now Remove the top lock nut, it is left hand thread, once removed, then just clean every thing out.  Metric O-rings from harbor freight 5.99 a box works fine

[Dr. Noisewater]

Thanks goldarrow, I have it all taken apart now. I tried cleaning it the best I could and didn't get far. It's soaking in degreaser now.

[ekpent]

You can soak it in a can of carb dunk.

[texianbiker]

Pure Simple Green works great and does no harm if you take the pieces out within 30 minutes or so.