XJ tank on a 79SF?

[corey]

Man, i super dig the look of the XJ tanks. Since I've bobbed the back of the bike and put a new seat on it, I think an XJ tank would really set it off.

Will any year XJ tank fit on my 79 XS1100SF? If so I'll start searching eBay.

Anybody know of fuel capacity differences between the two styles in question?

[DGXSER]

Not sure, But I think the tanks mount differently at the back or seat area. You may need to fab something to mount it. I believe TC has done this with Godzilla already.

[Bigfoot]

The XJ tank would not fit without modification but I am sure it can be done. I am pretty sure it has the same capacity as the standard. 5.3 gallons.

[TopCatGr58]

Yep, modifications are needed. I cut out a section out of the middle of the tail bracket that fits around both top frame rails to allow the front seat securing tab to be able to slide up into the holder. I also cut OFF the securing threaded shaft that is used to secure the back end of the XS tank, because the XJ tank is longer, and it would just hit directly under the end of the tank! Petcocks were a direct swap from my 81 specials tank, along with the sending unit, although is was on the other side of the center portion of the tank, had to cut the harness wrap to release more slack in the sender wire to allow it to reach the sender that's across the frame on the other side from where it usually attached. The front cutouts for the rubber mounts are the same, plug and play. However, the handlebar/triple tree MIGHT make contact with the front edge of the tank IF the bars are turned to the fullest extent, but I just remember NOT to turn them that far.

I just posted a photo in the "wanted to see a 110/90 tire" thread, but I'll post it here as well!


T.C.

[corey]

Thanks TC! I knew you'd have the answer...

I have a custom seat that doesn't implement the stock mounting setup. In other words I don't use the seat tang receiver welded under between the frame rails at the back of the tank. So I wouldn't have to cut the back flange of the tank?

About mounting the XJ tank, though... You say you cut off the threaded stud that slides into the stock XS tank receiver. How did you mount the rear of XJ tank to the frame, then?

Thanks to both of you guys!

[TopCatGr58]

I didn't!! I let the seat kind of hold it down. The edges wrap around the frame rails, and the seat is bolted down in the back, so it just sits there mostly braced by the front rubber mounts. You could make or weld a bracket to the OEM threaded post positioned farther back towards the seat to secure a bolt thru the long channel that the XJ has cut in the longer tail section to secure it down snugly if you are that worried about it!? See the diagrams of the tank on the Yamaha fiche site.

Found a couple photos from my tank painting project, you can see the notch I cut out, and the large flat tang section at the end of the tank, but the sides are curved to hug the rails!


T.C.

[corey]

Gotcha, TC. What years XJ tank should I look for? Only the XJ1100?

[xs11lover]

I'm doing the same thing on my xs12 standard project, but I'm not sure I like the look, now that I've spent the better part of a month filling dents, sanding, wet sanding and painting. If I can make the right seat, I think it will be ok. Here is a pic before I painted it.

[trbig]

It's bad enough for us XJ guys trying to find an XJ tank without you guys scarfing them up too! Go find your own models to play with!

Tod

[corey]

HA! Sorry TR... Yamaha should have made the XS tank as sexy as the XJ, then....

xslover: If you decide you don't like it, let me know what price you want for it.. I was wondering if I'd like it or not too... I just know I like the look of the XJs...

[corey]

xs11lover: Great look on your bike! Looking at your pic, I did something real similar with the back of my bike too. I chopped the last 8 inches or so off the frame though. I then mounted the brake in the frame tubes....

I need to get some pictures up...

[TopCatGr58]

Gotcha, TC. What years XJ tank should I look for? Only the XJ1100?

Corey,

The XJ's were only made for the US in 82, but were made for Canada till '84, so depending on where you're looking for them, eBay may have folks from Canada selling/parting some out, but otherwise, U.S. XJ's will be 82. But some parters don't always know what year bike they have due to errors in registrations, etc., but now you know what it looks like, so you should be able to tell if a guy is offering an XJ tank or an XS!
T.C.

[corey]

True that TC... but will a XJ750 tank work? I guess as long as the frame rails fit under the tank, right?