petcock position?

[goesto11]

1979 XS 11 SPECIAL: when parked for a while, petcocks on or off?

[natemoen]

Turn them off. It's extra protection. In theory the octy (of still there) will cut the fuel off, but could fail. In theory the floats will shut the fuel off but could fail. Just get into the safe habit of turning the petcocks off.

[goesto11]

thanks, but is there any harm in leaving them in 'on' position?

[crazy steve]

If everything is working right, no. This assumes that you still have the 'octupus' or 'octy' in place and it's functioning correctly. But these are imfamous for failing from age, and at that point you're now depending on the float valves at the carbs to prevent fuel flow when stopped. These are known to leak slightly too if worn (unless they've been upgraded to viton-tipped needles), and fuel can flow into the cylinders and dilute your oil. If this happens and you don't catch it, running the bike with contaminated oil will kill the bearings and now you need a new motor.

So like Nate said, it's no-cost insurance to turn them off...

[goesto11]

thanks for the replies! i never had a bike this old before, it's a learning curve....

[natemoen]

thanks for the replies! i never had a bike this old before, it's a learning curve....

It certainly is! But it is fun!

[brcree]

petcocks....

Let me chime in here for some help with mine......the petcocks I have now never leaked until I removed them and cleaned them out. Now I wake up this morning and gas everywhere. I don't have the Octy, replaced all fuel lines back the way they were. Had them in the off position as well...??????? Does it matter how the rubber piece with the holes in goes in?

[DGXSER]

HERE....is a thread I made on Special Petcock repair. No the holes should not matter.

As to the leaking of fuel, with removing the petcocks, you probably shook a bunch of the gunk off the bottom of the tank and it has now worked its way into the carbs and causing the floats to stick open. I'd add some seafoam and run it through and see if they clear up. Also if you do not already use them, get some inline fuel filters.

[brcree]

fuel

Hay D....I've got in-line filters already...and use Sea-foam alot, I just cleaned and adj. the floats last week and haven't ridden it yet...so I'm baffled as to why the gas everywhere....

[natemoen]

I am guess in you had them apart to set the floats, something just got hung up and if you were to give the a knock and the floats will fall back in line.

If you cleaned the petcocks out they may have had some crap on them (wouldn't even have to be much) that was helping to make a seal, by cleaning them you removed that helper material.

As to the gasket, yes it does matter how it goes in.

[cywelchjr]

Always the first thing I do if I get any gas leakage from MC carbs, it tap them with the handle of my hammer (it's rubber, don't want to actually damage anything) which will generally free up any hanging floats. Since I ride almost every day all year round, it's not likely to be a problem again for a LONG time.

(of course I'm pretty sure that's why I have a second engine in mine, the PO did have a gas pouring out of the air box problems, and likely gas in the oil too).

[DGXSER]

I'm betting you loosened some crud up somewhere that got to the floats, or you set them such they drop down lower. Check the gaskets in the float bowls are cut even with the edges of the bowls on the sides.

Also, depending on fuel line your using, that could be an issue. I've relayed this before I know, but it drove me nuts for a week or more. When I first rebuilt the carbs I got automotive fuel line from a local AZ store and re piped my fuel lines. Well, I had gas running every time I hooked them up. I cleaned those things till the bolt heads shined, and same thing, hook em up on the bike and a float leaked. They would hold great for the bench test, even the upright test, but put them on the bike and one of those PITA B'strds would leak. I finally figured out the nipples on the Ts in the fuel system was abraiding off little flakes of the soft rubber in the inside of th auto fuel line, and THAT was getting to the float valves and holding one open. I switched to Tygon type line and never had another issue.