1992 HD. Why is there Weak fuel flow to the carb?

look for gas tank vent. if clogged it will cause a vacuum in the gas tank and not let gas flow to Carb.

Some possible solutions (from general experience (i'm 55 yrs old)): 1. Plugged up fuel filter; Replace it. Part costs less than $10.00.If the filter is just in front of the tank, it should take a screwdriver and 15 minutes or less to swap. 2. Water in the fuel tank; Add a bottle of "Heat" to the tank. Cost ~ $3.50 or less. This next may require some trouble shooting or head scratching first. DO #1 & #2 First. (Won't hurt & Doesn't cost much) 3a. Partly clogged fuel line. 3b. Cracked fuel line. (Sucks air into the fuel line) Depends where the fuel pump is.(Also look for fuel leaks, especially around hoses in the fuel line.) 3c. Clogged carb.Filter (if it exists). Verify fuel delivered to Carb by disconnect @ Carb. attach small hose to catch container then turn on (NOT Start) ignition.Should hav a steady flow of fuel for at least several seconds. If so, Replace carb. filter. 4. Weak/ failing fuel pump. Major pain but backyard mech can do it with helpmay take half a day.May need to have a few empty gas cans available to save the existing fuel.. Replacement In-Tank pump assembly should be less than $50.00.

There are 2 different enigines on these depending upong your actual unit model number.
One had a Subaru 175 cc engine and the other was a Honda engine. For carb specifics I need the ENGINE model number. Either way... here is what you need to do:
1. Fuel selector off.
2. Remove main fuel line from the carb.
3. Use a spray can lid and check FLOW. It should fill the lid in under 8 seconds. (Feul selector OFF now) If you do not have good fuel flow here you need to inspect the tank exit port, in line fuel filter if used and the sediment bulb under the fuel selector for debris
(GOOD FUEL FLOW NOW)
4. Remove the float bowl by unscrewing the bowl nut from the bottom of the carb. NOTE positon of gaskets as you remove float bowl. Use carb cleaner and direct a spray hopefully with mini extension tube of the carb nozzle into the center of the threaded area of the bowl nut. (This cleans main fuel jet orifice / pin hole) Then spray carb cleaner using mini nozzle extension up the flat side of the float needle until carb cleaner exits the main fuel line connection. Last spray from the main fuel line connection to the float needle (reversed spray)

This usually removes any debris from the float bowl. main fuel jet and main fuel manifold Reinstall the main fuel line.
- Turn on the fuel selector and use the spray paint can lid under the float to catch fuel. It should fill in 8 to 10 seconds to the point your worried about over-flow.
- GENTLY lift the float needle to the level position. FUEL MUST STOP.
- Lower Float to resting position. FUEL MUST FLOW so that it would fill the spray paint can lid in 8 to 10 seconds. (FUEL SLECTOR OFF)

Clean the bowl nut and reinstall the float bowl. Turn on the fuel.. wait 30 seconds for the float bowl to fill completely and start unit. If it runs GREAT... If it only runs with the choke on you still have a fuel supply problem...i.e most likely the main fuel just in the threaded area of the bowl nut is still clogged. .

This should get you going. Thanks for choosing FixYa,
Kelly

Take the fuel line off of the petcock and check the fuel flow at the carb fuel inlet. Catch the fuel in a catch can and let it flow for a minute or so. If the fuel stops flowing, you could have a bad right side fuel cap and the vent is bad. The tanks vent from the right side cap. The vent hose under your dash could be bad as well not allowing your left side tank to vent. As the fuel flows out, air must be allowed in or a vacuum will form in the tank and stop the flow of fuel.

Good Luck
Steve

Hello,

It sounds like fuel is not getting through the system. You can check the fuel going the to carb by pulling the fuel line going into the carb. Check the fuel filter for proper fuel flow. The fuel pump could also cause your problem - you can disconnect the output line and test for fuel flow out of the pump.

Hope this helps. If you find this information useful, please vote on this post. Thank you.

Regards,

Oz

Ok a quick check. When the engine cuts out and you go for restart it dies within 5 seconds. Next time put the ignition at position 2 (on but not starting) and wait one minute, then start the car. If the engine again runs for 30 seconds before cutting off this tells you its is a fuel problem. If the fuel is supplied slowly it fills the carburettor fuel bowls and when the car starts it quickly uses up these local reservoirs of fuel faster than they can be replenished. When you try to restart immediately there is only a tiny amount of fuel and so it used up almost immediately. By leaving the ignition on 2 for while it gives the pump time to fill the carburettor bowls and this takes a while longer to run down when the engine starts. Just before moving on does the car have a choke OK remove the low tension connection to the coil, basically remove any chance of a spark. Put a big old towel around the carb. Now remove the fuel line at the carburettor and put ignition on 2 to engage the starter pump. Listen to pump operation and look at the rate of fuel being pushed from the disconnected fuel pipe. If the flow is slow check on pump and filters.

Check your fuel cap....try running your machine with the cap loose or off...you may have a clogged fuel tank vent... also check all the fuel lines to the carburetor to be sure none of them have degraded or have air leaks....also check your muffler to be sure it is not clogged ...hope this helps...;-D

My 5hp B-S is doing the same thing and found a post that seems to be the best answer. Replace the float. It runs out of gas if the float is not working properly.
Another cause may be the diaphram, maybe.
Mine is 12 yrs old so I plan on getting the whole carb rebuild kit
while I have it apart
Good Luck

there is usually a tiny filter on the pickup on the fuel tap, you need to remove the tap from the tank to get to it. Before that pull the fuel line off the carb and open the tap and see if it flows. If fuel runs out , leave the tap alone
There also may be some jets blocked in the carb

check the actual fuel line. Also is it fuel injection or carberator