Petcock vacuum or no vacuum!

I've recently had a starting issue with my 81 XY650. It seems to be flooding quite easily. I decided to start it with out the vacuum hose hooked to the petcock. After a bit, I eliminated the flooding, so I turned the petcock to prime. I left the vacuum unhooked and did not cover the vacuum port on the third carb. The bike ran better that it ever has. What would be the problem if I were to block both vacuum ports and continue to run using the prime position when its running and the regular position when its off? Also, why would the bike run better with the carb port open? I expected it to have a problem idling.

 

If the bike was running better with the vacuum port open (leaning out that cylinder) it tells us it's running rich for some reason. It sounds like you may have carburetor issues as well as the petcock problem, or maybe just need a new air filter? You CAN run in "PRI" and use "ON" as "off" (I'm currently doing that right now on one bike until I get my petcock fully rebuilt) but it kind of defeats the purpose of the vacuum operated petcock.

 

Does it matter which port the vacuum hose is connected? Has anyone ever connected all four together and then connected the union to the petcock?

 

1: No. Both my Secas came with it attached to #2, my spare head had it on #3. 2: Someone may have, but there is no need. The vacuum from one is enough to activate a properly working petcock. Petcocks tend to get "lazy" with age, even with no obvious holes in the diaphragm or anything. As long as the inside of your petcock is smooth and not pitted or corroded where the o-ring from the diaphragm seats, you can successfully rebuild it. It's a very simple but delicate mechanism.

 

FYI, the one thing that you might regret most from not using the vacuum line to the petcock is that you will lose your reserve in the tank. While in the PRIME position, the tank will empty and when you run out of gas....... you have no reserve to go to. At least it is that way on the one sitting here. Don't ask how I know.

 

Do all XJ's have fuel gauges, or only the SECAs?... Or only SOME of the SECAs?

 

750 Seca's do, not the 550 or 650.
Don't know about Maxim.

 

Hi

Were can you get a petcock rebuild kit for a XJ 1982 seca
posted to OZ

 

OH Chacalllll.