Twin strongburg carbs. "Will not idle"; clean fuel, rebuilt carbs, starts but quits after fuel runs out? fuel pump works, fuel check valve in bowl works-not stuck, ? MAYBE fuel not syphing into carbs?? wrong casket?? pleas help. [email protected] 9-10-2113

CHECK COMPRESSION ON ALL CYLINDERS

Check the anti afterfire solenoid is energized while ignition switch is in the run position.

Try draining the carburetor fuel bowl. If it runs after draining fuel bowl then empty the fuel tank(s) as that will be where the water is.

Dont forget to empty the carb bowl after draining tanks. It will take a few seconds of cranking after draining the fuel bowl as the fuel pump needs to refill the carb bowl.

the additive in gas eth. causes fuel lines to break down and not deliver gas to the carb. replace fuel line.

check fuel pump, remove fuel line to carb. turn motor over, if fuel does not spurt out fuel line replace fuel pump.

float in carb may be stuck, remove bowl from carb. and check needle valve, if gummed up clean.

Is the timing set correctly? Good set of spark plugs?
If so, it has to be a blockage in the carb.

Black smoke indicates that your mixture is way too rich. Now, you didn't say what carb you're running, stock or aftermarket. But, what it sounds like to me is the needle and seat in the carb is leaking fuel and overfilling the float bowl. When you're running down the road, you'll using enough fuel so that the float bowl does not overfill. When idling, you don't use as much fuel, the bowl overfills, and fuel flows into the carb creating a very rich mixture. Is you overflow hose that connects to the bottom of the float bowl connected, clear and open? If so, turn the petcock on without the engine running. If the overflow is clear and the needle valve is leaking, you should see fuel start to flow out of the overflow hose. This is very important that it do this. If the overflow hose is blocked and you forget to turn your petcock off, you could wind up with a couple of gallons of fuel in your engine. It will leak out of the float bowl, into the carb past the intake valves, past the rings and into the engine. I've also seen it get into the primary drive case as well. I'd put a new needle in the carb and check the float setting according to the book. it's sets with the carb on an angle if the carb is the original Keihin CV.

Good Luck
Steve

the problems is in the carburetor, common problems when unit does not run often and rust get get build up. get some automotive carburetor cleaners and spray it heavy in the carb, don't worried about flooding it or damaging anything, it will dry out faster than gas. (use little gas if you need to) try to start it up and get it running with the carb cover off and continue to spray carb cleaner in the carb while the engine is running, do this couple of time and hope that would clear it out. if that don't work you will need to take it apart and clean it. you have small tiny object obstructing the carb flow. the unit doesn't have a fuel pump, it run on gravity feed, the carb are easily obstructed. hope that help a bit

your fuel pump is diaghram actuated by pulses from crankcase pressure, if you look there is a small tube that runs from pump to valve cover, pull fuel line off carb and have some one crank it over to see if it's pumping. could be pump or blockage between tank and pump, if fuel flow seems good to carb, i would pull bowl off and check for dirt and also make sure anti run on valve, the thinghy that holds the bowl on to carb is opening properly, it should open and close when you turn key from off to run, beyond that it could be you have some water in your gas.

Fuel filter is located near the fuel shutoff valve within three inches. It is inline between the shutoff valve and the fuel pump (towards tank).

The fuel circuit is: Tank/Fuel Pump/Fuel Filter/Fuel Shut-off Valve/Carbs.

You first step is to check for fuel delivery to the filter. Make sure the bike is cool and no iginition sources are nearby. Disconnect the inlet line at the filter and turn key on and crank engine (to trigger fuel pump.) Do not try and start at this time (choke off).

If fuel is adequate to the filter, check the filter by blowing through it, it should easily pass air. Replace filter if questionable.

Next reconnect the fuel lines and remove float bowl drain plugs in the back of the carbs (2 per carb). If with key on and cranking fuel pours out of these ports then you probably have clogged fuel jets. If not then the float bowl needles / pipes could be plugged with varnish from dried fuel. You can try spraying carb cleaner into the fuel inlet to clear the varnish and then retest. Careful not to spray carb cleaner on yourself (wrap straw with a rag).

If you have good fuel flow to the carbs and bowls you probably have varnish plugging the jets. You should remove the carbs and clean them thoroughly.

Hope this helps,

Kal

If the engine fires on starting fluid, then you are missing fuel, so you need to start with the source, is fuel getting to the carb? if not why not. Check fuel lines, shut off valves and filters.
If it is, is the carb float allowing the bowl to fill?
If there is fuel in th float bowl, then you need to look at mixture and idle settings.

hope this is of some help.
Ed

Lets start with the basics. Is the gas valve turned on? Do you have plenty of gas in the tank. If not, turn the gas valve to the "reserve" position if your valve has a reserve setting. There may be a water trap bowl at the base of the gas valve. Turn the valve off and remove the bowl if you have one and then clean and replace it.

Next, drain the carburetor. There should be a screw on the lower side of the carb float bowl. Remove the screw then replace it after the fuel drains. Turn the gas back on and wait a minute for the carb to fill with gas. Install a new stock NGK spark plug and try to start the engine.
If the bike doesn't start after a couple of minutes then shut off the gas and remove the carburetor.

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray all the little airways and fittings in the carb. Remove the two screws on the outside of the carb and spray into the screw holes as well.

Be sure to put each screw back in the hole it came out of. IMPORTANT > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb. Let the float bowl fill then start the engine. This process should get you back on the road.

Pleas rate this as " FixYa " if my solution works. Thanks