250r quick change gas tank

[Billy Golightly]

For years I have thought about how to do this...with the rotax nearly complete and as tight as it is on everything I definitely need an easy way to pull the tank on and off quickly for plug changes, carb adjustments, etc.

Anyone have any thoughts or ideas on how we could (relatively) safely pull that off?

[oldskool83]

A lot of sport bikes use a clip style screw they locked in place with a 1/2 turn to hold all the fairings on. They come in hex head styles or flat head screw drive styles.

[Jmoozy27]

That and brass quick connect fittings on the fuel lines. I will get a pic of what im talking about. I use them on breathing air packages. They are not made for liquid but I think a conversion is possible.

[Jmoozy27]

212854

This threads onto a 3/8" hose. You may be able to apply it just below the petcock to minimize fuel loss. A normal pneumatic quick connect should work but lacks the safety lock. It would definitely take some trial and error.

[Billy Golightly]

A lot of sport bikes use a clip style screw they locked in place with a 1/2 turn to hold all the fairings on. They come in hex head styles or flat head screw drive styles.

I think I can envision what you're talking about, but I Have no idea what it really looks like or is called - if you can find a picture would you post it up? Something like that would be good for the back mounts that are shallow on the frame. The one under the tank or "front mount" is the tricky one I can't quite get figured out. Some kind of a little cam lock type thing would be pretty snazzy but I'm not sure how you would mount it

[Toaster556]

I think he's talking about Dzus fasteners, I've always found them to be kind of a pain to deal with. Below are the style most people use for securing fiberglass hoods on drag cars
212857
I'm not familiar with the 250R frame, but you could you run a hollow tube for the bottom tank mount and just use a large pin (for lack of a better term) secured by a locking clip, like a hitch pin on a truck?

[Flyingw]

I was toying with idea a couple weeks ago trying to find a way of addressing the tight radiator cap problem and the over-sized radiators. I have two ball pins that worked great for the front tanks mounts. Finding the right length ball pins for the rear couldn't be too hard. The grip length on the ball pins I have are almost perfect. They are about 3/16 too long but they do work on the front mounts and they do lock in place. I'll see if I have any shorter ball pins that will work on the rear.

[oldskool83]

Or od do a pin with a quick release clip found at lowes like most people put on axles, or come up with a flip tank option like sport bikes have due to this same issue with plugs.

[Billy Golightly]

I was toying with idea a couple weeks ago trying to find a way of addressing the tight radiator cap problem and the over-sized radiators. I have two ball pins that worked great for the front tanks mounts. Finding the right length ball pins for the rear couldn't be too hard. The grip length on the ball pins I have are almost perfect. They are about 3/16 too long but they do work on the front mounts and they do lock in place. I'll see if I have any shorter ball pins that will work on the rear.



Did you just run that all the way through the other side? Have to drill out the existing threads and go through the frame rail there?

[fordnut79@hotma]

I always just ran the back 2 bolts on my tank without trouble.that way I could just rotate it back when I needed to.

[The_Steve_Man]

All you would need is to disconnect the front mounts and radiator shroud bolts. If you had a long enough fuel hose, that wouldn't even need disconnected. and just flip it up.

[YTZ drew]

Here's a fuel-compatible quick disconnect if you choose to go that route. Parts Unlimited carries them so they're available thru your local bike shop or online thru Dennis Kirk.

http://www.motionpro.com/motorcycle/tools/category/quick_disconnect_couplings/

[hitmeup760]

Not trying to hijack this thread but I wanted to say thank you to Billy Golightly for the how to thread on polishing gas tanks, I tried it with the power cone and I got a dam good shine on my tank for the 85R. Good people and good advice with trikes makes a good day in my books.

[Red Rider]

In my opinion, for this to be worthwhile, the gas tank would need to be able to be removed without any tools whatsoever. If you do accomplish it, how much time is it actually saving you, maybe 5 minutes to remove 6 bolts & a fuel line? I realize it will be a hassle to go through the jetting process on this hybrid engine, but once you've got it jetted correctly, how often will you need to re-jet it? Do you ride in that many different elevation/temperature variations that it will be checked/changed constantly?

[Flyingw]

Did you just run that all the way through the other side? Have to drill out the existing threads and go through the frame rail there?Oh no Billy. The ball pins I have are the perfect diameter for the stock threaded holes. No drilling required. The pins are just a tad too long but that can be compensated with a small spring or a round piece of rubber or nothing at all. The fact that the ball end of the pin is long enough to go through all of the brackets, grommets, and threaded hole makes the ball pin a good choice for a quick release. The only requirement on these pins is the ball when locked has to extend all the way out for a firm lock and they did firmly lock in place. You can even put a small leash on the pins and attach them to the lower bracket by way of some small wire rope. I have a whole roll of plastic coated wire rope. I think it like 1/16" diameter. Small but strong stuff. Later tonight I will see if any of the pins I have will work on the rear mounts. I didn't get that far before I abandoned that idea. Now you could also put ball pins of the lower shroud bolt but those are 6mm holes. Smaller than the 8mm holes on the tank mounts. These pins I have are basically 1/4" diameter pins but ball pins are available in all sorts of diameters and grip lengths.

[Flyingw]

The rear mounts are different. The threaded flange the bolt threads in to is not a through hole. It has a bottom and the threads go all the way to the bottom. This does not allow the ball to extend and lock the pin in place. As you can see in the pic, there is some pin left. if the bottom of the hole was drilled through allowing the ball to fully extend on the other side of the hole then it would be good to go. The hole in the bottom only needs to be big enough for the pin to pass through ( the ball will be retracted going through the hole). The diameter on these pins is .24". It looks like the pin in the pic would be a pretty good length with a rubber grommet on it like that pin is in the previous pics.

[Flyingw]

Here's a site that has metric ball pins. All you need to know is diameter and grip length.

http://www.vlier.com/product_index/sld/qr_14_balllock-t-metric.html

[Flyingw]

Looking at the sizing chart, in order to use the metric ball pins, the threads in the holes would have to be drilled out. A 6mm bolt has an OD of 5.78mm or .22in. The 8mm bolt has a diameter of 7.79mm or .30in. The metric ball pins have a larger OD than the bolt so the treads would have to go.

ANSI Sizing Chart

http://www.vlier.com/product_index/sld/qr_14_balllock-t.html

[Mr. Clean]

WOW, Flyingw that gas tank is shiny and clean!!

[Billy Golightly]

In my opinion, for this to be worthwhile, the gas tank would need to be able to be removed without any tools whatsoever. If you do accomplish it, how much time is it actually saving you, maybe 5 minutes to remove 6 bolts & a fuel line? I realize it will be a hassle to go through the jetting process on this hybrid engine, but once you've got it jetted correctly, how often will you need to re-jet it? Do you ride in that many different elevation/temperature variations that it will be checked/changed constantly?

You'd be surprised. The worst part is when you're in super dusty and dirty environments and you can just feel the jetting change from shitted up airfilters and the like during the course of one day of riding. I keep my stuff jetted pretty tight and lean normally, but even with that a hot plug, sometimes when we are idling or going through the woods at the hill climb spot slow, you do a lot of idling and low rpm riding before you actually get to the next hill and have to clean it out good to get up, etc. Having to take the gas tank off in the woods to change a plug when that happens is not an ideal scenario...:)

Pulling the tank on the 250R is just one thing I've always found was a bit more cumbersome than it could be, so this is something I've thought about for a lot over the years actually.

[Billy Golightly]

Oh no Billy. The ball pins I have are the perfect diameter for the stock threaded holes. No drilling required. The pins are just a tad too long but that can be compensated with a small spring or a round piece of rubber or nothing at all. The fact that the ball end of the pin is long enough to go through all of the brackets, grommets, and threaded hole makes the ball pin a good choice for a quick release. The only requirement on these pins is the ball when locked has to extend all the way out for a firm lock and they did firmly lock in place. You can even put a small leash on the pins and attach them to the lower bracket by way of some small wire rope. I have a whole roll of plastic coated wire rope. I think it like 1/16" diameter. Small but strong stuff. Later tonight I will see if any of the pins I have will work on the rear mounts. I didn't get that far before I abandoned that idea. Now you could also put ball pins of the lower shroud bolt but those are 6mm holes. Smaller than the 8mm holes on the tank mounts. These pins I have are basically 1/4" diameter pins but ball pins are available in all sorts of diameters and grip lengths.

I'd never heard of or saw these, but I LOVE them already!! I will definitely pick some up and them out.

The airscoops, I think with some super strong earth magnets, you wouldn't even need a fastener at all there. I've kind had that part figured out in my head for a while, that front mount is the one that is kept me scratching my scalp for a while!

[onformula1]

A lot of sport bikes use a clip style screw they locked in place with a 1/2 turn to hold all the fairings on. They come in hex head styles or flat head screw drive styles.

They are called Dzus fasteners, they started in the aircraft industry.

[onformula1]

How about Dzus fastners for the two bottom shroud mounts

[____________spacer|lock washer|wing nut

And a “Axle” bolt for the front & rear mounts
(like the rear quick change axle on a motocross bike)

You can fab it out of steel rod, pig tail the end so it doesn’t turn, drill out the threads on the frame, run a spacer on one end to get it closer to the shroud & make a cool looking wing nut a ¼” away from the outside of the shroud they you can remove it quickly with no tools.

Quick release the fuel line.

[Flyingw]

The strength in a ball pin is in its shear, not the pull. As a rule, you don't want tension on the ball but a small amount of tension you would get from a grommet or something soft would keep the pin from rattling but as long as the ball is fully extended, that pin won't come out. Oh, and the pins actually have two locking balls. Send me your mailing addy and I'll drop some of these pins in the mail. I have a couple of parts bins of these pins.

[Flyingw]

and yes Mr. Clean, that tank shines so bright I have to wear my welding mask when the lights are on.