SuzukiSavage.com - Gas Tank Mod

JohnBoy Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 825 Gender:	Re: Gas Tank Mod Reply #15 - 07/07/12 at 15:08:46 With all the calculations did you come up with a total volume of gas? The Savage is pretty skimpy already. I do like the look however.
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John in Kalifornia

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Re: Gas Tank Mod
Reply #16 - 07/08/12 at 02:56:17

OK here's some specs:

Filled up the GS tank with water. Held 3 gallons. Suspect that gasoline would have close to the same amount of liquid.

The Savage tank is 13 inches wide. The GS tank is 10 inches wide.

Here's what I was talking about on the frame tilt.

I went to do some fitting of the tank this afternoon. Forgot the level and triangle. First of all, the wiring was in the way so I disconnected the plugs on the frame rail. When I tried to drop the tank down it wouldn't go very far in the front because of the mismatch between the tunnel and the frame backbone. The backbone had a square section at the front. This explains why the Ryca tank I looked at had a rectangular cutout on the front. I will have to modify the tanK so it will sit lower at the front by cutting the tunnel and boxing it it. This only has to be done at the very front as the main frame backbone drops down at an angle, as the above pics show.

Camera ran out of battery so there are no pics of me cutting the rear tab off the bike or hammering the tank with the BFH. The tunnel at the rear was about half an inch too narrow to fit over the frame rails so I had to massage it. Also the top of the tunnel needed so be relieved to make the tank fit lower. I had to quit when my tennis elbow started acting up. Next time I'll bring the kid to do the hammer work.

More later,

John in Kalifornia

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John in Kalifornia

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Re: Gas Tank Mod
Reply #17 - 07/09/12 at 21:36:06

Here's some more information.

The Ryca modded tank sits much lower on the frame. The gas tank normally has a bit of clearance above the frame backbone. When you try to drop it down you soon realize that the round tunnel won't go over the square frame tube. In order to drop the tank you have to cut the tunnel so it is rectangular and then patch the sides and top in with new metal. See this detail of a Ryca tank showing the squared off tunnel and welded insert. The angle of the photo makes it look as though the opening is wider at the bottom but it is a parallel cut. The tunnel is not very long fore and aft because there is a BIG HOLE IN THE MIDDLE OF THE TANK for the speedometer.

The size of the frame tube is about 1 3/8 inches square. I figure a quarter inch on each side so make the opening 2 inches wide. Box in some 18 ga sheet metal to close up the opening. I propose to form the u shaped channel over the frame rail, leaving a 1/4 inch gap on either side. Then I'll cut the tank to fit the channel.

The frame backbone slants down from the front. If I make so that the top of the tunnel fairs into the tank about 6-8 inches back it should work.

I'm open to suggestions.

John in Kalifornia

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Cavi Mike

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Re: Gas Tank Mod
Reply #18 - 07/13/12 at 23:31:38

Wait a second, which tank are you working on? The GS tank or the stock LS tank? That sure looks like a sketch of the LS tank but I thought this was a about the GS tank. I'm about ---><--- that close to buying a GS tank because I got the impression it fits well on our odd-shaped frame. I figure I'll have to cut the donuts off as well but I can just weld them back on wherever I darn well please, I don't trust my skills on a tank though.

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John in Kalifornia

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Re: Gas Tank Mod
Reply #19 - 07/14/12 at 01:24:23

If you look at the first post in this thread you will see the difference between the tanks. The GS tank is more "oval" shaped and the LS tank is more of a sideways teardrop. I'm not going to destroy the good stock tank but will cut up the junkyard GS one.

BTW, from my certified accurate measurement of 3 gallons the specs say it's from a GS250, not a GS450 or GS400 or some larger bike, if that means anything. Sorry, I don't have the length off hand. It came with plastic extensions on the front, probably to cover the frame.

I think any tank you get will have to be modified at the front to fit the tunnel, unless you want it to sit high like the stock tank.

Even though this will be as much work at least as the Ryca mod the end result hopefully will yield a skinnier tank without an extra hole in the top. I doubt that one can make the GS tank as sleek in profile (side) view as the Ryca tank because it isn't as flat on the top near the rear as the LS tank. Again, see the first post.

Got the welder lined up. Now to do some cuttin; and bendin' of metal. I've got a die grinder, angle grinder, sabre saw, sawzall and lots of hammers. No hot wrench, tho.

John in Kalifornia

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Cavi Mike

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Re: Gas Tank Mod
Reply #20 - 07/14/12 at 01:53:00

Even between trim models of the 550 they seem to be different. The one I found is almost a cross between the two in this thread but I'm almost certain it will "fit" where I'm trying to put it. Anyways, I put the hammer down and picked this one up.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=251096124744

If it's no good, I'm only out $43.

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John in Kalifornia

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Re: Gas Tank Mod
Reply #21 - 07/17/12 at 00:18:47

Here's the latest. Mikey and I went to work on the tank with our hammer selection.

Here's the results:

As you can see, we destroyed the petcock mounting in our quest to make the tank fit over the rails in the back. Here's how it looks on the bike:

We decided that it needed to be dropped lower in the front, settled on 1 1/2 inches. The width of the cut will be 1 7/8th.

To thin out the profile view there needs to be a cut taken off the bottom. This is almost parallel to the bottom of the tank.

The stock Savage tank is much higher in the front and also thinner in the back. When the Ryca mod the cut is pie shaped and the result is rather like a turtle in the side view. The GS250 tank is thicker in the back because of the top curve which is not as "flat" as the Savage item. This meant that we need to drop the rear on the frame lower than the Ryca tank sits. I think that the seat will have to have a thicker pad in the front to match the tank.

Here's a view from the top. Much more like a proper cafe or dirt bike look than the Savage cruiser tank provides.

What do youse guys think?

John in Kalifornia

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ToesNose Serious Thumper Offline Pardon me, do you have Hot Sauce? Posts: 1993 Mooresville, NC Gender:	Re: Gas Tank Mod Reply #22 - 07/17/12 at 04:49:39 Very cool John, thanks for keeping us in the loop!
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Cavi Mike Serious Thumper Offline Thumper n00b Posts: 1005 Rochester, NY Gender:	Re: Gas Tank Mod Reply #23 - 07/18/12 at 05:01:07 Holy crap. What's that hold now, about a gallon? hahaha
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John in Kalifornia

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Re: Gas Tank Mod
Reply #24 - 07/18/12 at 08:46:22

Actually I think it will still hold enough to go to the local biker hangout and back. Not going to be entering into the Cannonball Baker run. You can't have a skinny tank and still have good range. Hey this is gonna be a poseur bike ridden by an old guy or a kid with no racing experience; we ain't going far.

BTW, what thickness metal would be good for the filler pieces? I'm not too familiar with gas tank construction standard practice. Can't be too thick or my HF 18 inch brake would, er break. Just can't help buying those cheap tools.

John in Kalifornia

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John in Kalifornia

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Re: Gas Tank Mod
Reply #25 - 02/25/13 at 01:47:47

It's been a while but we finally got back to work on the tank. Welded up the tunnel so it sits lower on the frame.

I also made a rear bracket mount. You can see in the photo the original location of the petcock which would not work anymore because of all the metal banging we did on the tank. I put a plate over the old location.

Then I made up new mounting plates for the Raptor petcock. On one plate I installed a couple of 1/4-20 rivnuts. This went on first, next to the tank. Then I made up another plate to go over it that had clearance holes for the rivnuts. I soldered both plates to the tank. There should be a flat surface for the petcock gasket to sit on. To prevent leaks, I covered the whole mess with JB Weld and filed it smooth.

John in Kalifornia

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WD

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Re: Gas Tank Mod
Reply #26 - 02/26/13 at 11:04:21

Way too much like work for me. Good on you though.

I think my next tank will be off an old Honda ATC (3 wheeler). With my 2 toning done, the tank I was running looks puny. Really want to run my 4.75 gallon Mustang tank, but I'm way too lazy to stretch the frame at least 6" for it to fit.

Factory front mounts were cut off my frame years ago, should have kept them and just put a CL tank on...

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strang Senior Member Offline Posts: 387 london Gender:	Re: Gas Tank Mod Reply #27 - 02/26/13 at 14:09:37 With the main issue being the square frame - has anyone checked out old brit tanks: enfield, triumph, bsa? they are pretty large tunnel and squarish as well if I remember.
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WD

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Re: Gas Tank Mod
Reply #28 - 02/26/13 at 22:17:10

All of the popular models are too long. I test fit: Bonneville tanks from T120C-T150, BSA A10 and A65, a couple different Norton tanks, even Brough and Vincent tanks (worked at a bike shop with attached wrecking yard and salvage parts). Even Jawa and CZ tanks are too long.

Not only is the frame backbone square, it is short. Harley XL tanks are technically too long unless you get the ones that take through bolts into the tank base. And even they sit way past the frame split.

Other common tanks that are too big: HD Big Twins (any), Indian Chief and Sport Scout, Kawasaki VNs bigger than the 750, Suzuki VS and VL, most Honda CB/CL/VT, most Kawi KZ, most Suzuki GS, most Yamaha newer than the old D whatever 2 strokes.

You can make anything fit with enough modifications, I'm just too lazy to do the work anymore. Wink

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teabowl13

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Re: Gas Tank Mod
Reply #29 - 02/27/13 at 07:03:10

WD wrote on 02/26/13 at 22:17:10:

All of the popular models are too long.

Seems to me that would be true if you weren't planning to change anything else about a stock bike; such as the seat/seatpan.
In John's case here, like most of the RYCA bikes and similar builds such as mine, everything from the tank going back is going to be brand new, so the extra tank length is easily accounted for according to how you redesign the rear part of the frame along with the seat and so on.
WD is right; NOTHING is an easy fit. That's why John is having to do so much re-building on the underside of his tank. The guy who started my build decided to cut up and re-weld the frame instead of messing with the tank; that has caused a whole other mess of headaches. I've even had to replace my stock carb with a VM36 from Lancer to make space for the frame mods that he made. It's a PITA. Lips Sealed

I don't like the way the RYCA tank looks when it's chopped down, but honestly as far as their kit concept goes, it makes total sense; every Savage comes with one! So it's a lot easier to modify the original than to find a source of brand new tanks that work.

By the way, JOHN, the bike looks outstanding so far! That's a hell of a lot of work you're doing just to make that tank fit, but I can tell it's going to be worth it. Cheers!

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