Installing a Harley Sportster Gas Tank on a GZ250

[Kcarvajal]

PART 1

Here is my "How-to" on installing a Harley Sportster tank that I purchased from ebay with petcock for $59 plus shipping (A steal!!!). I purposely purchased a used tank because I am assuming that the inside has already been sealed. If purchasing new, ensure you seal it using gas tank sealer or (as I was told) rust could build up inside the tank from moisture, etc.

Also, note that the tank will not perfectly slide over the frame. There will be space under the tank which I thought is perfect for hiding the wires if you want to clean up your front-end. The gap is barely visible, if at all due to the front-end of the bike. Placement is your call.

Lastly, I've exceeded the number of images I can post so will have two parts.

This is my 2007 GZ250 purchased from Craigslist for $1700 with only 2,300 miles after I installed the sporty tank.




Supplies:
-Longer fuel hose (1 foot length should be sufficient. I bought 2 feet), unsure of the size. Just measure or take the original hose with you. (The mower section of Home Depot or auto parts store)
-New hose clamps
-2 1/2" bolt and nut for the front mount of the tank. I want to say I used a ¼ inch diameter bolt. I can’t recall. But obviously do not use a bolt that is as thick as the diameter of the frame tube or you will weaken the frame.
-Drill bit for the exact diameter of the bolt.
-1" clamps (x2) with rubber cushions from the electrical section of hardware store. In my case, Home Depot.
-Vacuum tube plug from Autozone or auto parts stores. Vacuseal or something was the brand of what I got. One of the pictures below has the plug installed. I will point it out. As for size, it varies. You can get a box with mixed sizes, or just take the original hose to the shop and they can tell you which one to use.

Installation:
A. Removing the stock tank:
1. Remove the seat to reveal the two bolts holding the tank. I unfortunately do not have a picture before removing, but you will see the piece that hooks the front of the seat right by the back of the tank held by two bolts.
(SAVE THIS PIECE if you plan to install a solo seat and intend to follow my other “how-to” install a solo seat without welding Soon!).

2. Once the bolts are removed, turn your petcock to "ON". The gas should not gush out while in "ON" position as the vacuum is what opens the line, but only when the engine is on. (More on this later.)

3. Disconnect the hose from the petcock first. NOTE: the fuel left in the hose WILL LEAK! Get a solo cup or something to catch the gas and position it before disconnecting. Ensure it is completely drained.

4. Pull the front of the tank up, which is just mounted with rubber pieces. There are no bolts other than the two you’ve already removed in step A-2 that are right by the seat. I removed mine with gas still in the tank. I just drained most of it after removal in a gas container that I use for mowing.

B. Installing the new tank.
1. Dry fit the tank by placing it based on your preference. I installed mine higher as I like the look. Just make sure your handlebar clears fully turned or you'll risk hitting the tank. (Will revisit this part later) Anyway, the sporty tank has mounting tabs in the front. See pic below - pre-painted.




2. Ensure the tank is level. I just eyeballed it by sitting on the bike with the tank on, unsecured. Once you're satisfied, mark both sides where you will drill the hole for the front bolt. I used a sharp screw to scratch the paint from the frame.

3. Remove the sporty tank and drill your first hole. I drilled mine center of the frame tube. Dry fitted again, and ensured the bolt fits.

4. You can drill all the way through from the original hole. But I thought it is safer to drill the two separately. So I dry fitted the tank again, and ensured the bolt fits in the first hole and the tank is still level. I ensured the left side marker is OK, removed the tank, and drilled the other hole.

5. Place the tank on the frame, and dry fitted yet again, this time with the bolt all the way through. If you need to enlarge the hole slightly, just stick the drill through both holes and move it around. You might damage the bit, however.

6. If you intend to paint your tank, now is a good time. You could've done it earlier in the process, but risk scratching during the steps noted above. Your call.

7. This is also a good time to clean up your cables using ties, etc. I painted my tank, let it dry and in the process I worked on the cable clean up. I've had to disconnect some of the wiring and tied them right on the top frame tube.

8. Dry fit again to make sure all the cables work, throttle and choke move freely with the tank on it. I fiddled with this a bit since I noticed my throttle cables were squeezed or kinked and would not snap back. During this step, I realized I only needed one throttle cable, which is the one to open it up, not to close. The other cable was actually slowing the close of the throttle.. maybe due to improper positioning of the cable, I don’t know. But I didn’t see a need for it with the spring there snapping it back perfectly so I removed it. I’m on about 300+ miles with this setup, local riding & highway, stop and go, no issues. The throttle has a spring, so it springs right back to close it. In the picture below, you will see only the left throttle cable is connected, the right one is removed.



9. Mount the front of the tank with the 2 1/2" bolt. Do not over tighten yet, until the rears are mounted also.

10. Place the clamps on the frame and position them to fit the bolt through the holes. These clamps can bend, so don't be afraid to do so.


11. Tighten ALL the bolts.

Part 2 is to connect the fuel hose.

[Kcarvajal]

PART 2

C. Installing the fuel line.

If the new petcock is not on the left (more than likely not on the sporty tank unless it was manually moved or specially built), you will need the longer hose to run it from one side to the other.
1. Plan the route of the hose and measure to make sure it is long enough. Think gravity here, so ensure the fuel hose is somewhat vertical and fuel will run down, not in a horizontal portion of the hose. Also ensure it is not sitting on a part of the bike that gets hot… like the engine for obvious reasons. (To others- heat, fuel… you get the idea. )

2. Plug the vacuum hose intake right on the carb. I tried other steps of simply inserting a screw on the hose and did not work properly for me. Idle sounded like the engine was about to blow. Plug works perfect, highly worth the $1.99 from the store.

Plugged vacuum
[attachment=3:12vg04hh]IMG_20110710_101834.jpg[/attachment:12vg04hh]

3. Add the clamps to the hose for both the carb and petcock, insert and tighten both sides.
Hose on Petcock:
[attachment=2:12vg04hh]IMG_20110710_101842.jpg[/attachment:12vg04hh]

Hose on Carb:
[attachment=1:12vg04hh]IMG_20110710_101854.jpg[/attachment:12vg04hh]

4. Turn the petcock to the ON Position and inspect for leaks. Shake the bike left to right, etc.
5. Start the bike. You may have to fiddle with the mixture for the best idle by twisting the carb screw, whatever you call it.
6. Check your handlebar clearance. I had an issue with mine since I have a drag bar and would hit my tank when fully turned or locking the front-end.

SOLUTION: I popped spare sink valve nuts from a bathroom remodel project right on the handlebar stop (name?). Clearance problem solved, and I can lock the handlebar perfectly.
Pic below:
[attachment=0:12vg04hh]IMG_20110710_103012.jpg[/attachment:12vg04hh]

Other than the clearance problem and a rattling gas tank cap (which I will replace eventually) the tank works perfectly! As mentioned above, I have ridden this setup over 300+ miles mixed with stop/go and highways with NO issues. I hope some of you will find this useful. Just felt obligated to mention though, as seen in other how-to’s, I’d gladly help with questions you may have, but I will not be held responsible for any damage or injuries caused by these procedures and improper installation.

Next up, “How-to install a solo seat”.

Thanks!
Ken

[Dupo]

Very nice write up. Made it a 'sticky' for future reference.

[Water Warrior 2]

Very clever rear mounting with the P clamps. A well done write up and a big + to you.

[jonathan180iq]

Excellent!

Keep up the good work.

[Black Warrior]

Originally Posted by Water Warrior

Very clever rear mounting with the P clamps. A well done write up and a big + to you.

:2tup: :2tup: :2tup:

[Rookie Rider]

Nice :rawk:

[blaine]

Awesome job.Thanks for the write-up,and pics.
:2tup:

[mrlmd1]

Where's the pics of the finished project?

[Kcarvajal]

Here it is for now. Sorry for the bad picture, taken at night. I've been planning on taking better pictures with my DLSR, but waiting to re-wrap the exhaust with black instead of the current one, which is what came with the bike when I purchased it (used).

Also, the first image is with the tank installed, but top view.

viewtopic.php?f=2&t=4562

This is my bike as it is today, with the new 19" front wheel, solo seat, drag bar, mirrors, turn signals, 16T sprocket, etc.

Thanks!
Ken

BTW, thanks for the sticky. I hope others will find this helpful for their own project.