ougaf

I found mine at Bikebandit.com. It was $75 + s/h.

I went ahead and ordered the a new petcock. I put it on and it is running great. Apparently, those petcocks have a lifespan of ~5-6 years. That's all that I can figure since mine was bad and the used one I put on had the same problem. It would be nice to find a simple way of testing one. Thanks again for all of your input!

I am thinking the same thing about the vacuum being messed up. The vacuum line goes from the backside of the fuel cock to the side of the carb. Last night I took the fuel cock apart and so no damage to the diaphragm or any real grime in it. After I put it back together I tried to test the operation of the fuel cock. In the Prime position, you can blow through the gas line and air will go through the valve. In the On and Res positions, you can blow through the gas line and air will go through the valve until you put your finger over the vacuum port. When you plug the vacuum, it closes the valve. There isn't an Off position which seems odd to me. I believe that the fuel cock is working the way it is supposed to??? It makes me wonder if there is a restriction in the carb that is keeping a vacuum on the fuel cock and keeping the valve closed. As far as the backfiring and misfiring, I am not sure why it runs fine when vacuum is disconnected from the fuel cock to the carb. He said that the only reason he plugged each end was to keep gas from coming out of the petcock and to keep trash out of the carb port. Is it possible that if a fuel cock is bad that the gas would flow through the vacuum line and into the carb and cause it to misfire? Thanks again for your help!

I have an 03 Suzuki LTZ400. I made the mistake of letting it sit a couple of months with some apparent bad gas. I tore the carburetor apart and the needle & seat were completely seized up. I replaced them and cleaned the jets. I put everything back together and it still ran really bad. I went ahead and took into the motorcycle shop. They tore the carb apart and gave it a thorough cleaning. When I went to pick it up the mechanic said that he got it running good, but the pet cock was bad. He said that he recommended putting a new one on it (~$110), but he would have to order it and that he had "rigged" it to where it would run fine in the meantime. He capped of the vaccum line at the carb and flugged the line coming from the pet cock and put the cock on Prime. He was right in the fact that it runs fine that way. I decided to try to find a cheaper alternative than paying the $100+ for the valve. I found a used one that came of a bike that was supposed to be working good when the motor seized up. I changed out the fuel cocks and hook back up the vacuum line. When I started it, it started missing and back firing. I plugged off the vacuum line again, put it on Prime, and it ran fine again. What are the odds that I have 2 bad pet cocks? Can the pet cock be taken apart and cleaned? Could this still be a carb issue with the vacuum? Any help would be greatly appreciated.