How Do U Repair Tanks

GAS TANKS

Gas Tank

¶ Gas Tanks. Every bicycle has to accept one somewhere. Gas Tanks come in three different flavors.

Steel Gas Tanks.
Plastic Gas Tanks.
Fiberglass Gas Tanks.

Most all Gas Tanks are steel. Steel has 1 problem. It rusts. They tell me that BMW is the only motorbike manufacturer that puts an internal coating (Red) on the inside of their Gas Tanks. I've seen a lot of rusted Gas Tanks but none from BMW, then this must be truthful. If you have a rusted tank, you are betwixt a rock and a hard spot. The best fix is a new tank. This is non always practical because rusted tanks are commonly plant on old bikes. A new tank can cost $400 to $500 dollars if you lot tin find one. Most old bikes aren't worth information technology. Sooo... what to practise?

There are several kinds of tank coatings offered for sale. I've only used one, the well-nigh mutual major brand, and I was not impressed. The tank I used it on was in like new condition with a small-scale scissure in the bottom that seeped gas. The tank had no rust in it. I cleaned, acid done, and coated the tank, per manufactory instructions. I allow it dry for two days with a very depression pressure level air hose circulating air to the tank. I put gas in and guess what?

Information technology leaked right at the fissure. I then soldered the crevice and that fixed it. I figure that if it volition non seal a good clean tank what run a risk will a rusty one accept. Others may have had better luck, but I don't like paying $thirty-$35 for nothing. It is as well true that I have not tried all the coatings on the market. The choice is upwards to you. One thing else to consider... I've seen a number of tanks where the coatings have come loose and it ends upwards quite the mess.

So what to do? If rust is the just problem here is what I do. I put some large nuts (off bolts, not the eating kind.) in the Gas Tank and milk shake information technology vigorously for a while. Then wash out as much rust every bit you can with gas. At present put the Gas Tank back on and put a run into through fuel filter in the gas line to the carb. This will go on any rust or dirt from getting into the carb. When the filter fills up with rust, modify it for a new one. This is the cheapest way to go.

If you have a small rust pinhole y'all may have a really bad trouble. The tank may look good on the exterior, just odds are the inside is all rusted out. Clean it out enough to solder or weld it and lots more holes magically appear. The only existent cure is a new or unlike tank.

If the leak is caused by a crevice or puncture yous tin repair it by soldering or welding the tank. The only problem is gas tanks tend to blow up when a flame is applied to them. Not good! The cure is pretty piece of cake, but might exist hard to do for the average person. You will have to have a tank of some kind of inert gas that volition not fire. Merely fill the gas tank with inert, non-combustible, gas (Like Nitrogen) nether slight pressure and weld away. No oxygen, no blown up Gas Tanks. Just make sure the tank is purged of whatever air!

I'm always surprised at how many expert welders don't know this. They attempt to fill the tank with water, flame off whatever gas, and BOOM they still blow upwardly. Right thought, wrong filler. For the average guy it might just be best to have it to a skilful welder who knows the fob. You can get a two role epoxy made especially for gas tank repair. I've used it a couple of times and the gear up held. But think that these epoxies work good for a limited fourth dimension. Sooner or later they will fail. Sometimes they seem to final forever... other times the same glue doesn't final at all. On an erstwhile wheel or in an emergency they practise seem to work well.

If yous have to go a newer, unrusted Gas Tank, effort a Motorcycle Salvage Yard. Take your sometime Gas Tank with you. You may be able find a Gas Tank off another make or model that will fit with a little bit of modification.

Now about fuel petcocks. Again there are 3 flavors.

Standard Fuel Petcock.
Vacuum on/Off fuel Petcock.
On/Off fuel Petcocks.

Standard Fuel Petcock The standard petcock has ON-OFF-RES (RESERVE). OFF is, well, off. ON takes fuel from a tube that sticks upwardly from the petcock trunk into the tank. When the fuel level goes below the summit of the tube, the carb runs out of gas until you turn on the reserve. The RES (RESERVE) draws fuel from the lesser of the tank. Both tubes usually have fine wire filter screens on them and another screen in the petcock itself. Non all Fuel Petcocks have all iii screens simply, almost all Fuel Petcocks have at least 1 screen.

Vacuum Off Petcock The Vacuum on/off type of petcock has a diaphragm that automatically shuts off the gas when the engine stops. Yous will see a hose going from a plumbing equipment on the petcock to a fitting on the intake manifold of ane of the carbs. This supplies vacuum to 1 side of the diaphragm, opening the fuel valve inside the petcock. These petcocks take 3 settings. ON-RES-PRI. ON is on. Reserve is RES and PRI is Prime. Prime bypasses the diaphragm then y'all can make full the carbs with gas after they take been drained. Ready it on PRI, fill the carbs and put it back to ON. Sometimes, ON is chosen MAIN.

ON-OFF ON-OFF The third blazon is only an ON-OFF valve. These are used mostly on racing machines which have no need of a reserve. Most fuel petcocks are adequately expensive to replace, considering what they are. Some are screwed together with tiny screws and tin be taken apart and fixed. Others tin can be taken autonomously, merely you lot can't get parts for them, and some are riveted together. The riveted ones seem to exist on newer bikes and tin only be replaced.

If there is fuel flowing but the valve won't plow it off, the prepare is easy. Just go a plastic inline valve from a backyard mower dealer and put it in the fuel line going to the carb.

If the factory doesn't take whatever replacement parts (similar the vacuum diaphragm) yous can, sometimes, get after market parts. I haven't used any because by the time the petcock gets this bad the bike is then old no ane wants to spend the money on it.

Under seat Gas Tank Some motorcycles have the Gas Tank under the seat. This gives the motorbike a lower eye of gravity and better treatment. That's the idea anyhow. Considering of the low position of the Gas Tank, these Gas Tanks accept an electric fuel pump to pump the fuel, through a filter, to the Carburetors.

Under seat Gas Tank There has to be some style for air to enter the tank every bit the fuel flows into the carb(s). If the vent becomes plugged the gas will not menses. Most times there is a minor vent hole in the gas cap. Now that the EPA is looking at bikes, those caps may have i way valves in them or exist sealed completely and the tank take a vent tube. Some of the Harley-Davidson tanks have two caps and one will be non-vented.

Older (1960s-early on 70s) Japanese bikes and bikes with two piece gas tanks (some Harley-Davidsons) volition have a crossover tube. These are a real hurting because you must bleed all the gas earlier you can take the tank off. Some crossover tubes are in the front of the Gas Tank and some are in the dorsum.

Under seat Gas Tank Back in the day (1968) I was working in a Honda shop in Salt Lake City, Utah. The Honda Factory trained pb mechanic said the best style to get the Gas Tanks off was this. Loosen the tank from the front fittings, pull ane side of the crossover tube loose but non off. Jerk the rear of the Gas Tank direct upwardly. Now yous could lift the Gas Tank off the cycle and empty it into a gas can through the Gas Tank fill up hole. Information technology seemed to work with a minimum of gas spillage. The newer tanks are much better.

A lot of dirt bikes now take plastic tanks, which are real swell until one gets a hole or crack. They do have some plastic glues out but I would not trust them on a gas tank. It is a good idea to proceed the plastic tanks (and any plastic) out of the sun equally much as possible. Plastic Gas Tanks and fenders, that are supposed to concluding forever, fall apart subsequently years in the sunlight. I speak from much bitter experience.

I don't know of any motorbike manufacturers that are currently using fiberglass Gas Tanks. I'grand non sure how fiberglass will handle all the E-x and higher oxygenated fuel mixes being sold now-a-days. Depending on who you talk to, it works skilful or does not work good. Take your selection.