Found a dual petcock tank that is in perfect condition. My current set up is single. Whats the best way to go about being able to use this tank?

benoist13

XS650 New Member
Messages
2
Reaction score
0
Points
1
Location
Madison, WI
My current tank on my 81 xs650 is a single petcock. I found a perfect tank to replace my battered old one, but it's dual petcocks. What's the best way to go about being able to use this new tank?
 

willis

xsive compulsive disorder
Top Contributor
XS650.com Supporter
Messages
2,012
Reaction score
4,811
Points
263
Location
Northern Indiana
I may have a blockoff plate I can sell you. If you can measure the distance of your mounting points I can check tonight.
 

Mickster

XS650 Enthusiast
Messages
77
Reaction score
139
Points
33
Location
Smithville, Texas
If your tank came with both petcocks you can modify one like I did. Mine had two, the one in the pic was leaking, but now has one. It has been leak free for over 2 years now.

Hack saw the flange off, fill it with JB weld, put the rubber O ring on and bolt it in.

1663793994221.png

1663794052753.png
 

650Skull

Cockytoo
Top Contributor
Messages
9,995
Reaction score
11,596
Points
688
Location
FNQ Australia
Joining the 2 petcocks up will also give you the full tank of gas. Blocking one side leaves some fuel in the tank because of the hump in the middle.

Also if one petcock started to leak then you will have the other one to use as a single.

Another question is.............what year is the tank you found. ????
 

benoist13

XS650 New Member
Messages
2
Reaction score
0
Points
1
Location
Madison, WI
Joining the 2 petcocks up will also give you the full tank of gas. Blocking one side leaves some fuel in the tank because of the hump in the middle.

Also if one petcock started to leak then you will have the other one to use as a single.

Another question is.............what year is the tank you found. ????
79 according to the place I got it at.
 

650Skull

Cockytoo
Top Contributor
Messages
9,995
Reaction score
11,596
Points
688
Location
FNQ Australia
79 had 2 tanks, A special and standard. Both had 2 vacuum operated petcocks............If the gas cap is to the right side of middle then its a Special tank
 

5twins

XS650 Guru
Top Contributor
Messages
23,454
Reaction score
19,645
Points
813
My buddy has been wrestling with a two petcock tank on his '80 for several years now. The big issue is fuel line routing. There's not much room under the tank for the extra hoses. The other issue is the petcock fuel outlets. The original single petcock exits towards the back side which gives a nice straight shot for the fuel line .....

FuelLineClip.jpg


The two petcocks on his "new" tank exit from the rear, like the old Standard model petcocks did .....

SideCoverGrommet2.jpg


His fuel lines are a jumbled mess, but then again, he's not the sharpest tool in the shed, lol. But still, fuel line routing is an issue when making this switch. Probably the best solution would be to use an original later petcock with the fuel outlet pointing in, and block off the other side.
 

grizld1

Grumpy old man
Top Contributor
Messages
4,369
Reaction score
5,405
Points
513
Location
Carbondale, IL
One petcock leaves only 4 oz.in the blanked off side of the tank. That's why Yamaha went with single petcocks in late Specials. The center-to-center distance between mounting holes from 1978 forward is 46 mm. A simple piece of steel or aluminum bar stock and a hand cut gasket will get the job done if you want to run a single petcock. I'd suggest the manual replacement from Mike'sXS, but I don't know if the same quality has been maintained over the years. All I can say is they used to be, and maybe still are, excellent. Anyway, the blanking plate doesn't have to be thick: 3/16"will do it. Use Teflon tape and copper washers on the screws and a good sealant like Gaskacinch on the gasket and you'll be good to go with a direct replacement for your current tank. It really is that simple.
 
Last edited:
Top