XJ650 petcock

Can anyone tell me if a petcock from a 650 tank will fit on a 750 tank without any issues. The 650 tank is an 82 XJ650 and the 750 tank is an 83 midnight 750.

 

Probably not, but then again maybe.

There were two "basic" styles of Yamaha petcock but also a lot of variants.

A few are shown in this article: http://xjbikes.com/Forums/viewtopic/t=25058.html

Generally speaking, the 750s were usually a "taller" version than the 650s.

 

Ok thanks for the link

 

don't the 750's hold the same 3.4 gallons as the 650?

 

The style/height/configuration of the petcock has nothing to do with the gas tank capacity. It's all about the "styling" and exact frame-to-tank-to-motor relationship differences from bike to bike.

Trust me on this one. It's nuts. The 550 Seca is different from the 550 Maxim which is pretty much the same as the 650 Maxim but the 650 Seca is different yet... and the one from the 750 Seca is WAAYYY too tall for the 650, etc., etc.

And that's only the original "standard body" unit. The large-bodied unit is equally varied.

What makes it even better yet is the fact that Yamaha's own parts fiche has it all wrong. Trust me on that one, too. Good thing we have chacal.

 

The Vacuum Operated Fuel Valve (Petcock), is a Part that Yamaha "Out Sourced".

The same Petcock is found on quite a few Bikes across several years.

You'll find some odd-balls, with Vacuum Ports and Fuel Outlets at different places ... (easily worked-around) ... but, it the Screw Pattern and Gasket fit without leaking, ... it will probably work just fine.

 

Not if it mashes into the top of the carbs with its output pipe.

PO had an incorrect petcock on my 650 Seca that caused the fuel lines to be harshly bent against the carbs.

Yes, there is a LOT of commonality; it's just that there's no pattern or sense to it.

 

Everything I've ever read and seen says the 750 tank will hold .9 more than the 650 tank. If your right then I guess I'm not losing anything ,but i just had the 750 tank repainted. I just wanted to take my petcock off my 650 tank and put onto the 750 tank.

 

the 750 tanks are bigger and .9 gallons sounds about right.

I put the petcock from my 650 into my 750 tank and all is well.