Fuel leak, Petcock and carb tuning

[Sean Shameless]

Hello all, I'm have a small fuel leak problem. I've read a pile of old posts here on the subject but each is a little different so I figured I'd start my own.
I've also included a pic of my petcock for clarity (that sounds dirty).

So I bought a somewhat modified 1981 XS400HS.
I bought it starting and running (and it did). The PO said the carbs were just rebuilt and cleaned but needs to be tuned and needed air filters.
After being parked overnight I noticed the next day that there had been a slow fuel leak. I traced it to the air filter boot.
I noticed the petcock was on res so I put it in the down "on" position but have since read either position should be fine and it shouldn't be flooding the carbs.
As a noob mechanic I just want to put a plan of attack together and run it past you guys.

-I'm thinking I could either temporarily add an on/off valve to control mess while working on things or should I just drain the tank?

-Then I can change the oil, filter and clean the sump screen. (I'm assuming it's full of gas at this point).

-Get a kit and rebuild the petcock And reinstall (following the guide on here) http://www.xs400.com/threads/how-to-rebuild-your-leaky-or-starving-petcock.8033/
Kit: http://www.siriusconinc.com/pro-detail.php?pid=&product_id=1787

-remove the carbs and check the float valve level using the service manual on here.

-reinstall carbs.

-Adjust the synchronization using the manometer here http://www.xs400.com/threads/cheap-manometer-for-carb-sync.5437/ and use the process in the service manual mentioned above.

Install the air filters and try it all out.
Air Filter: http://www.motorcycle-superstore.co...tlink&utm_medium=affiliate&utm_campaign=41227

I'm super green here so feel free to school me.

 

[arfstrom]

Reading this seemed like you just did everything. Your plans seem solid. So far, things I noticed, 1-non-standard clutch cable. so it seems you might be missing the neat thing that angles the cable to clutch device, part 11 in the attached pic. While your in there, see if the clutch actuator is showing wear. The spring seems to wear a path to freedom.

With fuel being dump out the boots, that usally means there is fuel in the oil. smell the oil.

Since there is some modifications already, it seems the petcock may have been changed already. so when you take you tank off, if there isn't a vacuum line running to the intake boot, then someone changed it to a non-vacuum petcock.

The fuel line, needs a new filter.

I do have a suspicion that the petcock needs assistances, I recommend putting a small oring, behind the big one, in such a way that the big one is being pushed to the front. I have a thread with pics somewhere. I have to get to work, good luck
Tobie

 

[Jeff0133]

Check if the P.O. messed with the carbs float levels...

 

[Sean Shameless]

Check if the P.O. messed with the carbs float levels...

I sent him a message telling him what was happening and asking if he had any thoughts.
I suggested I could rebuild the petcock, could check the floats, could clean and or/ rebuild the carbs.
I could also try to get a bit cheap and add an in in line on/off valve temporarily.
His response was "The petcock needs a filter inside tank". Followed by "Carbs are fresh rebuilt but need to be tuned".
Truth is I paid very little for the bike and bought it "as is" so I think I'm on my own. He seemed like a good dude but he's moved on from this project.
I know I'm in over my head a wee bit mechanically but with the internet being what it is I'm getting up to speed pretty quickly.
I try to do as much homework as I can before I ask questions so I front waste people's time on here.

 

[arfstrom]

Here is an excellent resource for petcocks.
Halfway down the website, (next link) you will see the original oring, and the new ones. my solution, would just have a mating surface that is protruded out more, and seal the hole regardless of crummy Quality control from the manufacture. The pic is from my photo album.
http://www.maxim-x.com/petcock.html


My filter has fallen out as well. for me, I know I can stick it back in, (todays project) It fell out due to being dropped. With out that filter, that means you do not have a reservior. so it doesn't matter if your on "On" or "RES" .
Ebay has this.
http://www.ebay.com/itm/YAMAHA-PETC...m3a68273699:m:m7vmFs7JR1wrNH2APhTmrOg&vxp=mtr