Topic: The Petcock Incident

[wedoo2]

One of the nozzles of my petcock came out today as I was pulling off the fuel line.  Can this be reattached?  Pounded in, soldered?  Gum?

[Gordon]

Just push it back in.

[wedoo2]

That just seems so...........easy.  There has been very little about this build that was   easy.

[Spanner 1]

Mine did that too..... just shove it back in, won't leak, should be o.k.

[wedoo2]

I did it.  Worked fine, but now that I am getting gas, the bowls runneth over.  Seems I don't know how to adjust my floats.  Everything is new too.

[Gordon]

What bike is this on?

[wedoo2]

74 550.  It's not been a really great day.

[verslagen1]

take a plastic handle of a screwdriver and wrap the bowls.
either your floats are stuck or the valve just needs a little help finding home.

[Kevin D]

My petcock did the same. I pushed the nipple in and then gave it a gentle rap or two with the hammer. New, supple, 5.5mm fuel line, and its been good for 10 years.

Also, cleaned/replaced float needles as necessary, smoothed float hinge pins and mounting posts, set float levels.

Also, replaced this petcock gasket under the lever.

No more leaks here.

[grcamna2]

I think the inside of that petcock brass tube deal there is a taper fit..I tapped mine in good & no sweat.

[wedoo2]

I got a rebuild kit for the petcock and it does not leak.  The nozzle does not leak now that it is back on.  I have new fuel lines and I completely rebuilt the carburetors, including new float adjuster valves.  I doubt that they are sticking, but I guess you never know.  I'm pretty sure all four are leaking.

So I am guessing that the floats are adjusted wrong.  Any other ideas before I wrestle them off?

 

[Kevin D]

Cracked overflow tube - I haven't had to deal with that.

I marked the overflow drain hoses to sort which were leaking.

Some use a clear tube screwed into the bowl drain as a sight level gauge. The level should be a bit below the bowl flange. I drained my float bowls into yogurt cups and compared levels. The picture shows a little less than perfectly even levels

If you search you will find stories and pics of all of the above.

take a plastic handle of a screwdriver and rap the bowls

+1

[Gordon]

Is it possible you put the floats in upside down?  Did you take them all apart at the same time or did you do one at a time so you could use the others as a guide to getting them back together correctly?  The floats should be oriented like they are in the pictures in this thread:

http://forums.sohc4.net/index.php?topic=22930.msg237780#msg237780

[wedoo2]

First of all I didn't think of the overflow tubes, but I read on here where someone had all four that leaked.  Sounds like a bit of bad luck, but could be likely due to whatever the cause of the failure was.  I am going to take the carbs off the bike today and check to see if they leak around the base.  Then solder them I suppose.

And it is possible that the floats are in upside down so I can look at that too.  This what one of them looked like after assembly.



This is how I measure the float adjustment, except I did use a metric ruler.



Comments?  Believe it or not, if you drop that slider with the needle in it on your foot, it will go through and stab your toe.  Someone told me that.

[Kevin D]

overflow tubes

Hairline cracks in the brass tube. Sealed with shrink tubing??

Also, I had one brass float that didn't float.

I very gently shined/deburred the marked areas at the float hinge, and the hinge pin, for better operation.

[Dimitri13]

Likely culprits of the fresh rebuild leaking: Fix

Float needle not finding it's seat: Tap it with a screwdriver handle or some size 12s.
Cracked overflow tube(s): Heat shrink tube.
One of the passages in the carb body is gunked up: Spray carb cleaner through each and every hole.
Each side of the float isn't even: Use a straightedge and verify both sides of the float are even.
Float(s) upside down (highly unlikely): The side with the indents go towards the carb body (as in the picture you posted)

Just from my experience with my own 74 550's carbs. The overflow tube was the main thing culprit, but everything else contributed. The way I tested it was plugging one side of the tube with my finger, and using a pressure gauge attached to the other side. I'm sure you can figure out the rest.

[Spanner 1]

One more thing.... bowl gasket can 'bow' in at the sides slightly when your putting the bowl up to the body and the gasket can foul the side of the float.... fairly common IMO as the float to bowl gasket clearance is very small.

[brokenspoke]

Comments?  Believe it or not, if you drop that slider with the needle in it on your foot, it will go through and stab your toe.  Someone told me that.

One might want to verify that needle isn't bent after dropping it on ones' foot. I lack experience on these type of carbs but on an old two stroke I had real problems with a bent needle.  I couldn't even tell it was bent without rolling it on a flat surface. Never managed to straighten it properly either, had to replace.

[Don R]

My brother tapped a petcock nipple back in and this year it fell out while on the trailer. He lost a tank of gas because he always leaves the fuel on. I was ahead of him on my bike fortunatly. I'd think about some red locktite or jb weld on the nipple, at least cable tie the hoses together.