new petcock not working-electrical problem?

[kirkh213a]

re jetted my carburetor, ordered new petcock, put it all together- no fuel will come out of the petcock. I suspect an electrical issue. when you do the suck test, the petcock needs electricity to function correct? how do I diagnose the electrical problem? is there a fuse somewhere that I haven't found? btw when I take the tank off and put gas in directly she runs nice.progress

[FJmonkey]

We need more information on the year of your FJ. It sounds like a Gravity Feed (GF) 84 to 87. The 86/87 petcock needs power to control the reserve function only, but it can be bypassed.

[kirkh213a]

86 fj1200 gravity feed.
why cant I blow through the petcock where the fuel should run through? shouldn't that be open for fuel to run through?

[FJmonkey]

86 fj1200 gravity feed.
why cant I blow through the petcock where the fuel should run through? shouldn't that be open for fuel to run through?

84/87 petcock 101 - You want the petcock to flow if the engine is running and not flow if it is stopped. That is why it is vacuum controlled.  When you crash/fall over it is nice to have the fuel cut off. 

[redwolf50]

Does it run for a little bit when you put the tank back on?if so check the fuel line routing...from experience it can and will kink..and shut off supply lol

[Fj.itis]

This might be a stupid question but is the vaccuum hose hooked up from second carb inlet to the petcock itself?

[kirkh213a]

thanks to everyone for helping me. I found a video on how the petcock works. I tried it on my new one and it works. so now the bike starts and runs! sorry I don't think things through before I yell for help. I do need to figure out why the tach doesn't work. should I start a new post?

[racerrad8]

So, did you buy a new Yamaha petcock or something else?

If you purchased the new Yamaha petcock then you have to hook it up to vacuum for it to open and flow fuel as already mentioned. You can leave the electrical portion unhooked for now as it is not to control fuel flow only acts a fuel reserve system. When it is unhooked the fuel tank can run completely dry.

Randy - RPM

<edit> I'm glad you got it sorted.

[Tripper]

I have the opposite problem, petcock flows with engine off. Is it rebuildable? Does RPM have replacements? New? (not giving my dealer the money if a board supporter can get it first) It's an 86 FJ1200.

[Pat Conlon]

Tripper, I answered your question when I moved it out of the Files.