My 60th birthday present

Mailman said:
I'll take readings again if I can ever have this thing running for for more than a few minutes.
My rebuilt petcocks drool so bad I can't un it very long.:doh:
Click to expand...

I had drool as well but I used brand new o rings and brand new fibre washers and it stopped. If it doesn't - then get yourself some of that Hylomar Blue stuff. It WILL stop a fuel leak Bob.

As I said earlier, I just googled it and it came via amazon.com from an aircraft maintenance place in, I think, Georgia.
 
Gary, that is a very thourough write up you did there. Very nice! I might have to give my petcocks a closer look.

Pete, I remember your experience with your leaking petcock. That's how I remembered the Hylomar.

I have a lot to think about. One way or another I will resolve this.

Thanks gentlemen for your input.
 
Hmmmm....Bob - can you identify from where the petcocks are leaking?

I bought two new (NON-vacuum) petcocks for Lucille from XSDirect / MikesXS because the originals were just too messed up to salvage and I had heard that rebuilding them was a dodgey proposition. They sealed up perfectly - the first time.

However, when I acquired the better looking tank for Lucille, I transferred the petcocks from the "old" to the "new" tank and I tried to re-use the little fibre washers on the mounting screws - and they leaked. Soooo, I bought several new sets of fibre washers and once again, with new ones in place, all was well again.

The point is - it wasn't the petcock body and valve arrangement that was leaking. It was the mounting screws - and they seem to require new fibre washers each time they are removed and put back on. I now will keep a stock of those magical washers and the oddly shaped o-rings on-hand for the next time I have to mess with my fuel tank.
 
Pete,
Yeah, I took a careful look to see where they were leaking. In this photo it was seeping around the black gasket that goes between the petcock body and the back plate.
image.jpeg
 
If that's the leak, it should be fixable with a thicker homemade gasket. Save the old part, even if it takes a week and $50 of gas to source the parts, that's how I do it.

Scott

Edit....Not recommending this, but............many gaskets have been made from cereal boxes.
 
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The gasket in my '71 petcocks is thin 1/32" neoprene.
Here's a 3" roll on eBay: http://www.ebay.com/itm/272170534966

You could take your petcock plate, smear a thin coat of grease on the sealing surface, press it onto the neoprene sheet, and it'll leave an impression that can be used as a cutting guide. Well, that's how I do it...
 
I used cereal boxes to make seals for the tappet covers many years ago, but I varnished them and left to dry for a few days before using them. In my youth I made a head gasket from cardboard and it lasted about 10 seconds before it blew out. Following that I used about 20 layers of aluminium cooking foil and it lasted many months. I have replaced the fibre washers on the pet cock with copper washers and they have sealed very nicely, but the washers must be annealed first before use or reuse.
 
Copper washers - nice! Those fibre washers are not expensive, but I have found that without a new one on a screw each time - that screw WILL leak.

Cheers,

Pete
 
...... but that's not the part that's leaking on yours.
 
Weekend update, Tuning phase
I started out by replacing my drooling right side petcock with a brand new one just for expediency sake.
IMG_4364.JPG
The way it was leaking just wouldn't let me run my bike long enough to try and tune it. I plan to keep my two petcocks that I had previously rebuilt ( but still leak ) and really clean them up and polish up the castings and cut some new gaskets and keep them for spares.
I filled my tank and watched carefully, no leaks! Yay!

Then I adjusted the cam chain tension, it was not far out of adjustment.
Then I moved on to adjusting the valves. I was pleasantly surprised to find they were almost dead on. One exhaust valve was one, one thousands too loose.

Then I wanted to set the timing but the points were kind of fried, so I installed a new set that I had and gapped them and got them all set.
IMG_4360.JPG


I then went to set my timing and I was having a hell of a time. The bike was missing and wouldn't idle well. The timing was jumping around, I kept changing my timing light pick up clamp back and forth from one spark plug wire to another, I felt the exhaust headers and the left side was hot but the right side was not. Then I could no longer get my timing light to pick up on the right side wire. WTH?

IMG_4363.JPG

IMG_4362.JPG

The wire pulled right out of the spark plug boot. So I cut the wire off about a quarter inch and cleaned up the cap with a wire brush on the Dremel and re assembled it.
When I re started the bike it fired right up and the timing settled down and I was able to set it . I checked the advance when I revved it up and it looked good.
The bike starts quickly and I can get the idle down to a low rpm, but if I twist the throttle, even a little the rpm takes off and climbs up to about 3,000 rpm and hangs there. And it's hard to get it to come down. The rpm's climb and fall of their own accord. I am wondering if my advance springs are shot. I can't figure it out.
It still has an intake air leak, I have not yet pulled the carbs to replace the mounts. I did however try covering different spots in my carb with plastic wrap to try and see if it would stop the leak. No Luck.
So I intend to change the carb mount on the right side where I hear the leak.

I also figured since my spark plug wires were messed up and my rpm's were so inconsistent , I might as well install my Pamco and see if it settles some of these issues.
So after all this I have pulled all of my stock ignition components ( except the advance unit).
So I am ready to install my Pamco and I have already run into a snag.
I CANT figure out how to mount the coil. It doesn't fit my stock coil mount. The kit I bought from Mikes includes a standoff mount kit, but it doesn't fit my frame mounts any way I can think of. Does anyone have any photos of their install? I may make a separate post in the garage because I am stuck until I figure this out.
Here is the coil I am trying to install. Anybody know how this mounts? The mounting holes on the new coils are wider than the mounts on the frame.
IMG_4375.JPG


So please if you have any photos of how you mounted your coils please share.
If you have any thoughts on my rpm's hanging up please share.
I feel like I'm getting close. Today I had the bike running longer than ever before.
Also just an aside, I re tested the charging. When the bike is idling at 1000 to 1100 it is charging about 13.5 volts when the rpm go up just a little 1200 to 1500 it jumps up to 14.3 to 14.5
So that's where things stand right now.
Until next time
Bob
Edit: after posting this I did a forum search and found several posts regarding coil mounts.
 
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GeorgeOC just did a really nice install on his '76 the other day - it looks very tidy.

Pete
 
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I assume you looked at the PAMCO site regarding coil mounting:

http://www.yamahaxs650.com/installing_the_coil.htm

I noticed that the pictures show the coil mounted in reverse with the leads approaching the spark plugs from the front. I wonder what the pros and cons of this are?? I think it would remove some of the clutter near the fuel tap. On Youtube the video XS650 History only shows the XS650SH with this configuration.
 

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