Larger Fuel Tank

dyenfd

New member
I just queried Clark Racing - Clark Manufacturing about producing a larger fuel tank for the CTX700.

It seems to me that a new fuel tank could be made that would completely eliminate the plastic that covers the fuel tank. The tank would be incorporate the same bottom dimensions as the existing fuel tank, retaining the same contour of the center shelter assembly (the plastic covering the tank) and eliminating the pocket area.

I would estimate the new tank would probably be between 5-6 gallons. I suspect there is enough interest and perhaps someone could post a survey that could be forwarded to Clark. It would probably need to have a few price set points. For example, I'd be interested in a replacement tank at 5.2 gallons at a max of $350.00, with a preference for a tank that would use the existing fuel sending unit, and incorporate a locking gas cap.

Fred$(KGrHqNHJDcE7y)0n,jWBPFFcztC7w--60_35.JPG
 

Steven

Member
An extra 2 gallons would be nice. That would give a range of about 300+ miles per tank. Forgive my skepticism, but I don't see how that's possible. I'm not a fabricator, but it seems to me that the plastic would still have to fit on to cover things like the air filter and how would we attach the plastic for the fairing? I'm not saying it can't be done, anything is possible, but if it can be done without affecting the appearance of the bike, then it sounds like a good idea. Of course it will make the bike a little more top heavy.
 
I think Clarke would have to sell a lot of tanks to recover the cost of the mold (they do rotomold plastic tanks, mostly dirt bike stuff) while keeping the price of the tank within reason.

One drawback for them is that on the faired bikes the tank cover is incorporated into the fairing and they'd have to come up with replacement mounts for the fairing and other bits of tupperware that attach to the jettisoned tank cover. The evap canister and rebreather solenoid bolt to the tank and would need to be accomodated too.

From what I've seen on my bike the tank would probably need to get significantly taller to add enough fuel to make it worthwhile.

A custom metal tank will run $800-2000.

The easiest thing to do would be to trash the plastic and slice the stock metal tank horizontally above the flange where the top and bottom join and which holds the tank mounts, and add in a strip of steel to raise the top of the tank for more volume. I suspect few CTX owners would be keen on the aesthetics of that.
 

rickster

Member
I wonder how many people would go to the trouble and expense. I guess you Iron Butts and other mile eaters would find a use for more fuel. The fuel capacity may be a bit small on the CTX, but the excellent fuel efficiency makes up for a lot of it. For instance, running summer gas here in the Golden State, I'm pushing the high 70 miles per gallon, but let's say I'm getting 74 mpg. Using all of that 3.17 gallons of fuel would give me 235 miles before I morph from biker to hiker. If I were riding a Harley Road King that carries 6 gallons and claims 45 miles per gallon, I'd be down the road 270 miles before looking for a beer to cry in. A whopping 35 miles difference. For old guys like me who live a caffeinated lifestyle, most of us aren't candidates for staying in the saddle long enough to take advantage of more fuel on our bikes.
 

ofdave

Member
It isn't a bad idea but I fill up between 160 and 180 based on where I ride and it has not been a problem.
I think you could gain some tank if the "glovebox" were eliminated and the tank top raised where the existing fill cap is with the cap moving to the top of the lost glovebox area. This would put the filler high as it is on the majority of tanks.
The glovebox is nice but I would learn to live without it. I think the tank lid could be made to still function but the cap would be where the glovebox lid is.
But I'm guessing you would not gain a gallon doing that.
 

MJC

Super Moderator
Well I do not know about you guys but I would love to get a CTX DCT without the plastic (totaled by insure company) cheap. And remake it using a reg gas tank, fork mounted fairing and 1" (mini app) pull back handlebars. Plus longer foot boards and a longer and higher (rear) brake paddle.

But that is not going to happen. Maybe I could take a Vulcan 900 LT and install the CTX engine and DCT into it, then we have something...lol.

I do have a call (s) out to bike junk yards for the ctx dct, but so far nothing under $3K. The bike would have to be running, and a running bike is hard to find.

Just my 2 cents, or crazy 2 cents..............
 

dyenfd

New member
Michael:

I think you're correct. I just ordered a used tank and spoke to a fabricator who will get back to me in a couple of weeks. My plan is to slice the tank and add a new top the same size and shape as the tupperware. If anyone else is interested, I'll let you know what the fabricator gives me as a ballpark price. By the way are you the same individual I dealt with years ago when I designed a spin-on oil filter for the Yamaha XS650?

Fred
 
Fred, I suspect your oil filter dealings were with Michael Morse @ Vintage Brakes. Michael has also been running 650central.com for some years. FWIW, I discovered some years ago that a 250 Ninja alternator can be fitted to the XS650, this is probably common information now.

For my CTX-FF project I've spent a lot of time going back and forth trying to decide between front and rear tanks which may or may not require electrical components/battery to also be moved around. At this moment I'm pretty sure that I'm going to go with a rear tank like an NC. The rider will be sitting more forward, on the horizontal frame rails, and a front tank was going to get very tall once the back section of a stock tank was eliminated for seating area and that taller/heavier tank was going to have a smaller mounting base so I have concerns about it being stable or wanting to over-stress the mounting points.

An NC tank is probably not of much use as a starting point for me as it encroaches into the back of the seating area, so rather than buying one and tossing most of it I'll probably start from scratch with an aluminum tank.

Keep in mind that 1 US gallon is 231 cubic inches or a cube just a bit more than 6.125" on a side, or 1.6" tall X 12" x 12". You could get enouch cubic inches of some foam that would give you however many gallons you want to add and then cut it/glue it to the tank to see how that changes the size of the tank and where you can best add the extra capacity.

cheers,
Michael
 

MJC

Super Moderator
OK guys if you are going to do this, this is what I would do:
I have the fairing model, so this idea is for that model but may work for the other model.
Take the gas tank and look at it with the plastic around it. There are a lot of spots that one can add to the tank. The space between the tank and plastic is all there. All you have to do is drill holes into the tank and add metal in the shape of a cup (you would have to make each cup to fit) in these areas between the tank and plastic. Next cut out the fill, add metal to that area, next using the fill put it in the storage area, and weld away. This way you would have the space between the tank and plastic, and the existing fill locution used for fuel and the fill in the unused storage spot. This would gave you maybe 1 to 1.3 gals more. And you would not have to have a finished look to it, saving costs. If you try to make a tank to replace the plastic it is going to cost over $1000. If you used my idea, maybe $300.

When I 1st got my bike I was going to do this. But never found a used tank so I put it on the back burner. I did mark up my tank when I was working on it and had my plastic's off the bike to see if it could be done. And it can. If you look at the tank there is a 3/4" seem on each side and working around that you could add a 1/2" more to each side, I would say that each side would be 1/2" by 12" by 8", plus the area that has the fill in it now, is like 6 by 6 and at least 4" high. And if you wanted to go crazy you could use the space for the air box and go with a K and N open air filter. That has to add maybe a 6 by 6 by 4" (more) space. If you do the math (which I can not) you would know about how much more gas you could hold before starting. My guess is 1 gal plus the air box space, so maybe 1.3 gals. Now you are talking 75 to 100 mile more range. Just a note here, I think you could add even more space to the tank but went with smaller sizes, and did not add the space from the filler to the tank, which you could use some space there too. I also went on the small side so everything would go back together easy and you could still use the plastic parts as is, saving some money on the finished look of the bike.

Try checking it out on your bike, just my 2 cents. BTW I went with a extra gas can on long trips, and have never used it, found a place to get gas every time so far. I also found that I have to pee way before I need gas. LOL.
 

rickster

Member
Took my bike from my home at 345 ft. in elevation into the mountains yesterday. It was all mountainous riding and I ended up at a lake at 6,410 ft. elevation. There was highway riding to get up there and highway riding to get home. A good mix. Today, I took the bike around the neighborhood before filing up. Here's what I got:

mileage.jpg

82 miles per gallon. If my tank isn't dented, it still has .65 gallons left in it which at 82 mpg would give me 54 miles left for a total range of 260 miles before I'm standing on the road wishing I had stopped at that gas station 2 miles back. I can't sit on the bike for more than 180 or so miles and a gas stop then gives my butt and mind a needed break. But, that's just me...
 

Steven

Member
That's impressive. I once road with a stiff wind pushing me from behind and I got over 300 miles on a tank, (different bike with a bigger tank).
 

Merlin III

New member
With my age, back, legs, and Prostate, I can do fine with the tank we have. A couple buddies that ride H-D baggers are amazed that I can go so far. They have to stop 50 miles before me. Of course they're running engines that are 2.5 times the size as the CTX, and they (with their passenger and gear) outweigh me by about a thousand lbs. 180 miles...2.5 hours...pit stop time.

I am with you. Every two hours and somewhere around 180 miles and I need a Red Bull. :)

As for the Harley riders, they also get tired because of the shake factor from those Harley engines. :)
 

Steven

Member
Yep, age takes it's toll. When I was younger I used to knock out about 1k miles a day. When the ride started I was mentally fresh, but after so many hours my mind became dull and it was just a matter of endless hours of blank thoughts until I got to my destination. I'm really curious about how my body will take a long trip these days. The longest trip I've had lately was about 400 miles in a day, but with frequent stops. Hopefully I will be on the road in a few weeks and I think 500 miles a day (off the Interstate) would be a good goal to shoot for. Even at that it will take me 3 days just to get to the first leg of where I really want to ride, i.e. Montana to Utah. Sometimes I think that it would be better to take the Interstate until I get out west, but then what would I miss?
 

BobWitte

Member
Yep, age takes it's toll. When I was younger I used to knock out about 1k miles a day. When the ride started I was mentally fresh, but after so many hours my mind became dull and it was just a matter of endless hours of blank thoughts until I got to my destination. I'm really curious about how my body will take a long trip these days. The longest trip I've had lately was about 400 miles in a day, but with frequent stops. Hopefully I will be on the road in a few weeks and I think 500 miles a day (off the Interstate) would be a good goal to shoot for. Even at that it will take me 3 days just to get to the first leg of where I really want to ride, i.e. Montana to Utah. Sometimes I think that it would be better to take the Interstate until I get out west, but then what would I miss?

Lots of cornfields I imagine!! ;)
 

Merlin III

New member
I've got an Iron Butt 1000 on my bucket list, I just have to get into shape to do it. Right now I'm laid up with a swollen right knee, and not even thinking about going to my local coffee shop, until Saturday. I can imagine... wearing a back brace and knee braces, asking someone to help me get on and off the bike. "Can you hurry up? I've got to make a thousand miles in the next 24 hours." I can pull up close enough to the pump to fill the tank, and I can carry all the water I need in the left saddlebag, but how about the "other part" of the pit stop? I'll be hobbling into the Am/Pm like Chester on Gunsmoke.

Just a side bar to the OP subject and your knee problem. A few years ago, I attended the Cro-Mag rally. I was camping and one morning when I crawled out of my sleeping bag, my back went out on me big time. I couldn't get on the bike (BMW 1150GS). I got some riders to help me on the bike and aim me in the right direction. It took me two stops for gas and other necessities on my way home where I had to ask random people to help me on and off the bike. It was amazing how accommodating people are to motorcyclists. Carry on!
 
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