Indian Gas Tanks

[rms337]

My originals were swiss cheese in multiple areas, so I bought these tanks from Iron Horse 8 years ago and they have been sitting in a box until now. Matt had an option to tin at the time, so I had them dipped. Does anyone know how much of a gap should exist between the top lips of the tanks? After a couple of days of finagling, grinding, pounding and on/off 100 times, I think I am getting close with the tanks and instruments overall. The new rubber strip from Greer's is a very stiff rubber about 5/32 thick (.154 if I remember) and the tanks are 1/16 apart (.065). Fitting with the rubber on requires that I clamp down pretty tight at the rear of the tank to get the tanks to squeeze together, but then it seems to distort the rubber a bit.

I think I would be fine to widen the gap a bit, maybe another 1/16, but just thought I would ask if anyone else has done this before I start grinding. Already had to do a repair on one tab as I got a little ahead of myself when fitting the first time. I also had issues with fitment over the speed cable attachment, but that will have to be a different post.

IMG_2203.jpeg

[Tom Wilcock]

Why not just shim the tanks out with washers?
Tom

[PRG]

Howdy sir,

For years Jerry Greer sold (encouraged the use of) rubber washers to mitigate vibration on original fragile tanks for which I have them fitted on my 348. Using the stover nuts in this kit allows you to run your fasteners more lightly fastened without concern for the nuts coming adrift.

https://jerrygreersengineering.com/p...1948&modelid=2

[ChiefTwoKicks]

What I've done when fitting fuel tanks... I make sure there is enough room for whatever is going to be between the tanks, i.e., wiring, speedo cable, coil & plug wires, and in my case, a 5/16" rubber hose vent line from the cam cover, long enough to reach the rear fender behind the battery box area.

On one of my bikes, with the early "fat" speedo cable, I had to 'glue' small flat washers to the frame where the tanks bolt to the frame. (I didn't want anything to rub or touch between the tanks). I simply used JB Weld to attach the small washers. My concern was the mounting tabs, that famously crack or cause leaks on soldered tanks. The mounting tabs must be parallel with the frame.
With all the stuff between the mounted tanks, its easy to understand that something could be in a pinch when the tank mounting bolts are fully tightened. There isn't alot of room there !! I've added the small washers to 3 different bikes, which made a big difference when finally tightening the mounting bolts. The rubber strip used to fill the gap fits easier (I've used rubber adhesive to fasten one side of the divider strip, so it stays with one side of the split tanks). The small washers (6 total) only add about 3/32" width to the space between the tanks.

The other area of concern is the the speedo/ cable mount. The tank sheet metal may have to be ground off slightly so that the cable nut is NOT allowed to touch the tanks. There should never be any binding or pinching when mounting the tanks. ever.

I've done this to all my bikes, never had any problems. makes mounting and aligning the tanks alot easier, without any binding or rubbing between the tanks. Good Luck.

C2K

[rms337]

Howdy sir,

For years Jerry Greer sold (encouraged the use of) rubber washers to mitigate vibration on original fragile tanks for which I have them fitted on my 348. Using the stover nuts in this kit allows you to run your fasteners more lightly fastened without concern for the nuts coming adrift.

https://jerrygreersengineering.com/p...1948&modelid=2

Thanks, Peter. A couple of questions since Greer's does not list the rubber washers. Do you remember the thickness? Obviously they are going to compress, so wouldn't want to buy them too thin. Looking at McMaster, I found these ( https://www.mcmaster.com/rubber-wash...aling-washers/ ), and they have 3 different thickness's. My assumption is that placing these in between the frame and tanks helps, but what about also using rubber backed washers on the outside? Just an idea. I do have the stover nuts already, but glad you mentioned.

Thanks to the others as well. I did make sure the tanks were sitting completely flat to the frame mounts. I started by tightening the front top bolt first and I could see that the tanks bowed out about 3/16" on the other end. To clamp down on the end would have just created a stress on the joints, too C2K's point. First thing I found was that there were 3 very small drops of tin from the tinning process that had to be smoothed out on the back of the front tabs and that took out the majority of the play. The rest was a little bit of careful tweaking on the tab and a little filing on the frame mount before I go them to lie completely flat with no stress. Using a flashlight to look for gaps and high points really helps as well.

I did grind out the area around the speedo cable to allow for a gap. My biggest issue was that the tanks were sitting right on top of the solid end of the cable fitting (not flexible). I ended up having to tweak the tank lip up a bit on both sides to prevent touching the speedo cable and allow some room for the rubber spacer. Maybe I will post that on another thread for some thoughts and/or opinions.

Appreciate the input!

[PRG]

Howdy sir,

Couple of years ago when lowering the compression on this. 348, decided to freshen those washers (were originally about 1/8” thick or so) with some locally sourced to avoid the hastle of ordering/waiting. Strolled into Lowes and got a set out of their specialty fasteners drawers in the hardware section. Being a bit thin just doubled them up at all three mounting points. As mentioned here, definitely don’t want to stress the rear tab on original tanks, a friend of mine sacrificed his antique leather jacket beating down the flames on his 440 after it came alight when fuel leaking from the left side tank dripped on his mag.

https://forum.antiquemotorcycle.org/...-head-cracking

[tfburke3]

I have a sheet of general purpose reinforced black rubber about 1/16"I just use a 1'' hole punch and a 3/8 to make the washers.
Tom

[exeric]

This Shop Aid shim die set is one of the most useful tools I own.

SHOP AID SHIM PUNCH KIT WITH CASE MACHINIST TOOLING | eBay

[T. Cotten]

This Shop Aid shim die set is one of the most useful tools I own.

My most useful tool, Eric,...

Is the lathe I use to make dies and punches.

.....Cotten

[exeric]

I agree with that, Tom. I have a box full of home-made dies, and punches for one-off applications.

[tomfiii]

With the speedo cable clearance,if cable too high between tanks put the dash on and see if speedo is parallel to dash. You may have to grind frame to change angle slightly.