When your Petcock is too big for its britches

[Grimly]

Just keep looking, because there are some petcock bodies on the third party market that utilise a brass blanking screw on the un-used side, and they definitely can be used according to which side you want the outlet to be on.
If yours is the 50mm hole spacing, you might be out of luck... so...
The alternative is to simply get one with the outlet you want and make a carrier plate that will allow you to use a 44mm pitch petcock that suits your needs - the carrier plate is of 3/8" steel and bolts to the tank, the new petcock uses one of the screw holes for a longer screw that goes through both, while the other screw goes into a tapped hole in the steel block.
You would, of course, have to drill and file a pass-through slot for the pickup pipes.

[jdub6092]

That appears to be the case with the current 'best candidate'...

spetcock.jpg

If only I could do the same with the fuel port. (Of course, even with the original part's left side location, the outlet had an immediate right angle to the rear of the petcock (towards the engine) before you connected the fuel line (see original post) so I guess in this case, another factor will be how 'acutely' the fuel hose can be directed to the rear of the petcock and towards the carbs without affecting flow.)

Looks like you may have had the same dilemna that I had. Original taps on the left, fuel tap 90 degree bend and could not find the correctly oriented replacement.
Ended up getting one that looks exactly like the one in the above pic. Switched the vacuum cover to the left, but had to double the length of flexible fuel hose and loop it around to avoid kinks.

[jharvey]

The final chapter – for now?

So, the search for a petcock with a left side output was unsuccessful. Even companies that market dozens of the things, like Tour Max in Japan, didn't have a direct replacement or anything else that could substitute. Oddly enough, there were plenty with left side exits in the non-vacuum category, or the single 3/8 thread types that fit into bikes like Harley's, but nothing with the 44 mm mounts (and the right side exit on the 'best candidate' match above would still bang up against the sidecover).

But, even though the petcock was replaced all the way back in January (of course with Canadian winters, I wasn't doing much riding until a month or two ago), the mechanic never threw out the original (I expect, as I would have, he keeps used parts around in case he can make some use of some of their components later). So, after he found it, and with me having given up on the search for a proper replacement, he Frankenstein-ed a repair with parts from other petcock repair kits (naturally, there are no repair kits for this old part either).

After a few hours riding, it seems to be working, but he wouldn't guarantee that the diaphragm wouldn't fail at some point - given the petcock's now non-standard construction. He expected the tell-tale symptom would be gas leaking into the crankcase and my inability to start the bike after it was parked for a day or more. I asked, "so if it was going to fail, would I expect to be experiencing this tomorrow morning or three months from now?” and he shrugged his shoulders and said, "yes."

Nevertheless, keeping a good thought, it may only 'fail' after a long and productive life, and given that the bike’s 45 years old already, some other thing might prove non-repairable long before the petcock is a factor again. Fingers crossed. If not, perhaps I'll explore the 3/8 to 44mm adapter plates (though I wonder if dropping the petcock down by the thickness of the adapter might not have it conflicting with the airbox - I'll cross that bridge if I have to come to it).

Anyway, assuming that good thought pans out, that appears to be the end of this particular saga. Thanks again to all those who gave their input.