That Special gas tank is quite small, smaller than the Standard one, and I know gas mileage isn't very good with a sidecar. With all you've done to the bike, you might consider fitting a larger tank. Many use the tank from an XS750 or 850 triple.
-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
-
It's time to vote for the bikes you want to see in the 2025 XS650 Calendar! Vote here!
Fuel Petcock ID
- Thread starter Nelson
- Start date
Nelson
XS650 Enthusiast
That's something to look into. I have a nice stainless steel 5 gallon jerry can that mounts at the back of the sidecar. Originally it had a standard plain old red jerry can with decals from everywhere we'd traveled covering it, but even though I still have that can it is so cruddy inside it is no longer any use. Besides, the stainless steel can goes good with the chrome on black color theme.
Nelson
XS650 Enthusiast
I checked on ebay to see what the availability and price was for XS750 tanks and it looks promising. When doing such a conversion is there any issues with fit such as tank hold down position or interference with the seat? I won't be doing it this summer but it would be a good winter project, since next summer we are planning to retrace our honeymoon trip thru Alberta and a larger tank would definitely be better, even with a spare 5 gallons available.
Nelson
XS650 Enthusiast
By the way, although I am not a native tri-citian, I have lived here since 1986. Moved here from the DC area to take a job with DOE. I am however a native Washingtonian having been born in Monroe and grew up in Everett.Nelson ,
Kennewick Washington
Welcome ! From Richland
Nelson
XS650 Enthusiast
A little more complicated. Grind off the old ears on the frame and weld on the puck studs from the original tank. I cringe every time I drill or cut into my brand new powder coating on the frame for some mounting of a part I missed during mock up before getting it powder coated. My original plan was to get the bike fully fitted up and running before a complete disassembly and powder coating, so that wouldn't happen. Unfortunately I didn't follow that plan.
PS you can easily drill out (3?) spot welds to remove the ears.
Bending the rear tang of the xs750 knee dent tank to where it will utilize the existing fuel tank post on the 650's frame will give you a couple millimeter clearance of the tank to forks when they're fully turned to their stopping point. Close!
Thus mounting those posts to the frame is pretty critical in their placement. I followed Aldo's procedure with drilling through the frame and fabbing a couple copper plumbing end caps to hold the pucks.
Thinking the tunnel of the tank had to be knocked in a bit to clear the backbone.
One of the unforeseen advantages (?) is that the xs750 tank is a wee bit wider at the front, making a wind tunnel of sorts over the engine head. No comfirmation but it sure looks it.
A cold chisel will knock those ears off the frame right now. Three small welding spots.
With that being said, there's no need to remove them as the end result placed the pucks about 4mm above the existing 650's ears. I never played with Barbie dolls or GI Joe. These bikes are about as close to the experience with all the swapping of parts and pieces you can do. Keeping the ears on you can always go back.
Edit add……
Two inches of the forward end of the seat and pan has to be removed due to the longer tail end of the tank.
Thus mounting those posts to the frame is pretty critical in their placement. I followed Aldo's procedure with drilling through the frame and fabbing a couple copper plumbing end caps to hold the pucks.
Thinking the tunnel of the tank had to be knocked in a bit to clear the backbone.
One of the unforeseen advantages (?) is that the xs750 tank is a wee bit wider at the front, making a wind tunnel of sorts over the engine head. No comfirmation but it sure looks it.
A cold chisel will knock those ears off the frame right now. Three small welding spots.
With that being said, there's no need to remove them as the end result placed the pucks about 4mm above the existing 650's ears. I never played with Barbie dolls or GI Joe. These bikes are about as close to the experience with all the swapping of parts and pieces you can do. Keeping the ears on you can always go back.
Edit add……
Two inches of the forward end of the seat and pan has to be removed due to the longer tail end of the tank.
Last edited:
Nelson do you at least have a “Standard” tank on there?
Yes, an XS750/850 tank has an appealing shape but there are plenty of modifications required to use one. I’m surprised there isn’t a known and discussed alternative UJM tank which is easier to adapt. ?
On a sidecar setup if modification is required anyway perhaps a huge BMW /5 /6 tank would adapt as easily ? Idk
Pics ?
Yes, an XS750/850 tank has an appealing shape but there are plenty of modifications required to use one. I’m surprised there isn’t a known and discussed alternative UJM tank which is easier to adapt. ?
On a sidecar setup if modification is required anyway perhaps a huge BMW /5 /6 tank would adapt as easily ? Idk
Pics ?
Nelson
XS650 Enthusiast
I am closer to going with another tank seeing as how the "chrome" Yamaha badge on the right side of the tank broke today...I can glue it back together or maybe find a replacement on ebay, but if I'm going to have to putz around with the tank I have I might just as well pick up a larger tank and make a winter project out of it.
I did get the tank mounted today and plumbed up to the carbs so today I actually got it running. I had started it on starter fluid a couple of times over the last week but it would only run a dozen or so revolutions before running out of starter fluid. It really sounds good so I am trying to get a bunch of niggling stuff done so I can take it to "Hogs and Dogs" (a local annual motorcycling get together where everyone brings their bikes to show off and have hot dogs). It is this Thursday so it's iffy if I'll have it going, but we'll take the HD sidecar outfit. Maybe I'll see XSTime there. I'll either have a white Harley sidecar outfit or a black Yamaha XS650 sidecar outfit.
Nelson
XS650 Enthusiast
Should have some pics later this week. If you are going to Hogs and Dogs this year I will be there either with the black and chrome Yamaha XS650 sidecar outfit or a white and chrome Harley sidecar outfit.
Thursday nites I drive truck for work so won’t be attending “hogs & dogs” unfortunately
If you want free gold tank emblems , come get ‘em
-R
Bob Wegman
XS650 Enthusiast
I have a decent or quite nice ( I think anyway) tank from a 77 XS750D ( the maxi maroon color) I may make available because I haven't got around to diving into a sidecar project for a XS650. So, If you decide you want to go that route for a winter project maybe I can provide some help.
It has been done if you have a spare XS650 tank, use the tunnel itself or use the dimensions to get one fabricated and replace the XS750 standard tank tunnel with the XS650 one. This increases the capacity 5 liters, from 17.5 liters to 22.5 liters.
Be going from 12.5ltr, (3.3US Gallon), XS 650 special tank to 22.5ltr, (5.94US Gallon), XS750 modified tank
Last edited:
Pics and price for any others interested?
Nelson
XS650 Enthusiast
Thanks for the offer but I need Chrome tank emblems. I JB Welded the original back together as a temporary fix and have a set of silver ones coming from ebay. Hogs and Dogs was fun but smaller than past years. I think it has been several years since the last one due to covid or some such. Only one XS650 was there and it was very pretty. Had a 2 into one intake manifold (frame modified to allow the carb to be directly centered behind the engine. Also had a hydraulic clutch. Was unable to find the owner as everyone was wandering around looking at all the other bikes. Hope this event picks up again to it's former gloryView attachment 328892
Thursday nites I drive truck for work so won’t be attending “hogs & dogs” unfortunately
If you want free gold tank emblems , come get ‘em
-R
