Custom Fuel Tank, Gas Tank

[veniceverges]

With the popularity of motorized bikes and the limitations we have with these gawdy kit tanks. I think Custom Gas Tanks deserves it's own forum category.

I'm currently building a custom tank. I'm using aluminum and at this point doing a lot of guessing.

If you've built your own tank, please offer up your stories and advice. As well I've looked for forums on this here but haven't found any yet. If you've posted, would you please give me the link?

I'm particularly clueless on how I'm going to do the gas cap and petcock So please help if you can.
I've seen lots of photos of amazing tanks.....just wanna know how you went about it.

I'm open to any and all advice.

Attaching a current photo. Only about half way there. Those front forks need to be chopped still and a nice Brooks saddle will finish it off nicely.

 

[dag_29307]

Welcome to the forum and the addiction. Enjoy the Ride.

I haven't made any tanks yet. But SilverBear has made some Great tanks from Apple juice cans. Type that in the search. Don't forget these are gravity fed tanks not pressurized. I was designing a tank for my MB and I get halfway through the plans and I remembered the gravity thing.....Duh! Just don't want you making same mistake.

 

[taddthewadd]

I made one out of PVC but later found out the gas can melt it over time. Have you done a search on tanks? There are a lot of threads on homemade tanks from welding aluminum to soldering big juice cans. And you mentioned the cap and petcok. I think it is Pirate cycles that sells a cap setup you can incorporate into your aluminum tank and Sick Bike Parts sells a good petcok.

 

[veniceverges]

Thanks Dag and Tadd.
Hadn't considered the difference between gravity and pressurized. The way mine is designed, the petcock sits at the lowest point. This should be good enough....yeah?

 

[dag_29307]

That should not be a problem. I found through exp. that the top of a PVC cleaner can works great as a fuel neck and cap. Just solder in place. make sure you have some type of breather so your tank does not build up a vacuum as the fuel is pulled by gravity. I have seen people (myself for one) use check valves on top of their tanks as breather. Just a couple of ideas to help you along. Do your research and don't be afraid to ask questions, That's what we're here for.

BTW enjoy the ride and welcome to the addiction

 

[taddthewadd]

I was going to use a check (one way valve) on my tank for a vent too but didn't. At first it seemed great because it would let air into the tank and wouldn't let gas out. Then I realized that if the tank sits in the sun or something then it could build pressure and possibly explode. Instead I used a regular brass barb and coiled a piece of fuel tubing so if fuel tried to come out it would have to go through the coiled tubing first. Some have used a fuel filter on the vent tubing so if gas sloshed out it would get cought in the filter. If this is clear as mud ask for clearification. Sometimes I am not the best at putting my thoughts into words.

 

[Junster]

This tank was a $28 dollar ebay auction. It's from a Yamaha Enduro 60. Came with a cap and several dents. It didn't take much to bondo out the dents. The mount you can't see is a piece of 1/8" flat steel welded to the frame straight down with a cross hole and a small metal plumbing nipple welded in the hole then trimmed to fit the width of the mounting holes on the tank. The rear is a painted piece of pvc trimmed to fit. I may built a "hook" for the back welded to the frame. I just wanted to thoughly test the durability of the front mount. It's just painted with Krylon Fusion paint for plastic. So far it's holding up to the gas really well.

 

[Venice Motor Bikes]

The problem with a gravity fed tank is that if the petcock is lower than the carb, the gas can't flow up hill to get to the carb!

So the main problem with making a 'in frame' tank in that style cruiser frame, is that the lowest part of the tank will usually be lower than the carb... so try lowering the engine as far as possible so the gas can flow down hill.

 

["the prussian" Shop Dogs]

Love the idea of forum section for tank fab . I have built several tanks both in frame and saddle bag .using steel for now as i only have hobby welder at shop .have learned a thing or two though, i hear you in regards too the petcock height,there are several small fuel pumps out there but all expensive. Most ive seen are sold at high end hobby shops that cater to rc airplanes. Some run on as little as four volts but they all push WAY more fuel then a two stroke needs (in my opnion). One tank i made had a low swoop to it for looks but inside i put in a little bulkhead to raise fuel level, but volume was lessened????
Ive milled off little bits of mounting blocks too lower engine but that creates other issues sometimes. So what can be done ? Pressure system ,vacum pres,small mech pump off mag? Or hi perf carb with built in pump running off white wire? Just tossing it out there...
P.s. Would love to post tank pics ,cant post from ipad ???

 

["the prussian" Shop Dogs]

Forgot to mention that napa sell cool little petcocks for four bucks ill try and post part number asap.

 

[wayne z]

Has anyone experimented with diaphram type carbs for this application?

They have built-in fuel pumps. Way better adjustment range. A primer would be needed for starting. The all metal snowmobile or aircraft plunger primers would look good on retro type builds

Another option would be a small, crankcase pulse driven pump, like used on snowmobiles,ect.
I have one on my ultralight that's mounted 20 inches above the fueltank and delivers 3 lbs pressure.
Then you might need a fuel pressure regulator, cuz the stock HT carb float needle is made for gravity feed.
That's all pricey stuff though.

Chainsaw or weedeater type with a built in primer bulb would best use of available cheap tecnology. Prolly more maintenance though cuz diaphrams and primer bulbs don't last too long with ethenol in the fuel.

 

[curtisfox]

You should look under paint both find Tinsmith's in frame tank.
Some Tecumseh 7hp and smaller had a diapram carbs. And chain saw carbs will work all you need in the inpaulse of the intake manifold or crankcase tapet cover. I know a guy that put a chain saw carb on a Farmall Cub and even hooked up the govener.......Curt

 

[dag_29307]

Wow.....It seems we have a "Shakesperian" among us. Prussian that is a rather interesting signature. I may put that i some scroll work on my next pait job, as long as you don't mind.

 

["the prussian" Shop Dogs]

Dag ive been called alot of things ,but thats a new one , use it all u want.
I tried a weed eater carb on a grubee ,it drew gas fine ,but engine ran at Very high rpms and overheated fast. All that after spending a day makeing a adapter plate and air cleaner. Theres a couple snowblower carbs that have primer bulb ,will try that next. But room between engine and frame is always an issue.
A pump that ran off a seprate bowl float might work. But thats getting a little complex for an mb.

 

[Allen_Wrench]

With the popularity of motorized bikes and the limitations we have with these gawdy kit tanks. I think Custom Gas Tanks deserves it's own forum category.

.

I second this motion and move for a decision from the moderators. What say you? Such a category would fit nicely under the present heading "Motorized Bicycle Mechanical Components" which currently covers such other things as Cylinder Heads and Lighting and so forth. And I have observed a marked interest in custom tanks, not only among the vintage and BT fans, but also among those custom builders who found a kit tank impractical or unusable. I think it would quickly become a popular focus point for tank builders and those who need their work. Please consider this option for us and let us know what you think.

 

[BarelyAWake]

An interesting suggestion - but ofc, a fuel tank isn't really a "mechanical component" strictly speaking... our Paint Booth & Chop Shop subsection is already ideally suited for fuel tank discussions.

Although perhaps including "tanks" in it's description would help folks find what they're looking for, I'll pass that along

 

[wolfstone7]

Keep Ace hardware in mind for petcocks and also fuel line by the foot. Also the local lawnmower shop has different size tanks avaliable, might not be what your looking for but worth a stop.

 

[biknut]

If you've built your own tank, please offer up your stories and advice. As well I've looked for forums on this here but haven't found any yet. If you've posted, would you please give me the link?

I posted this thread yesterday about making a tank out of fuel bottles,

http://motorbicycling.com/f6/custom-fuel-tank-made-camp-fuel-27428.html

 

[biknut]

An interesting suggestion - but ofc, a fuel tank isn't really a "mechanical component" strictly speaking... our Paint Booth & Chop Shop subsection is already ideally suited for fuel tank discussions.

Although perhaps including "tanks" in it's description would help folks find what they're looking for, I'll pass that along

I wasn't really sure which forum would be best. Please feel free to move it to where ever.

 

[camlifter]

maybe we should change the name from paint booth and chop shop to paint and fabrication, might get more people to look in then.