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85 virago 1000 has new carbs and floats still stuck

430 Views 7 Replies 3 Participants Last post by  SemiFast, 
chrisj32902
i rebuilt the carbs cause the floats were stuck and were continuously dumping fuel, no luck after the rebuild. I replaced the carbs and still dumping fuel into the rear cylinder. I think the fuel pump is not shutting off and is dumping gas into the carbs, causing the floats to be stuck. Should i replace the fuel pump? or is there a relay or some electric component that is bad? Mind you i know nothing about electronics. Im pretty mechanical but electronics is not my forte. By the way these are hitachi carburetors
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D
Did you buy brand-new OEM factory carbs from authorized dealer? If not, they're used and just as clogged and dirty as your originals.

  • Did you completely disassemble carbs down to every last single nut, bolt & individual component? If it can be further taken apart, do it.
  • Scrub out secret hidden passages in carb-body with PEA-based fuel-system cleaner and scrub brushes?
  • Did you ultrasonic soak everything?
  • Poke out all bleed holes in jets, emulsion-tube, carb-venturi with matching gauge soft copper wire?
  • Micro soda-blast everything before re-assembling?
  • Replace all rubbers: float-valves, pilot-screw O-rings, fuel-rail O-rings, float-bowl seals, even slide-diaphragms if needed
  • Set float-height with final wet-test to confirm
  • Sync carbs with manometers.

Any of above if not done will cause you running issues. Carb's aren't "easy", send them to pros with decades of experience customcarbservices.com, Professional motorcycle carb cleaning . Guaranteed to have your bike running like brand-new off showroom floor! :)

Also how is fuel-pump wired? Driven by proper fuel-pump relay? Or just generic on/off relay or worse, on/off switch? Fuel-pump relay is pulsed by ignitor, which then pulses pump. So pump DOES NOT RUN until engine is spinning!!! The faster engine spins, the more ignition pulses per second and more fuel-pump relay pulses to pump which flows more fuel. This allows pump to vary its output to tiny bit at idle/low-RPMs and increase volume at higher RPMs where extra petrol is needed.

Sounds like you've got both carb AND fuel-pump wiring issues.
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chrisj32902
DannoXYZ said:
Did you buy brand-new OEM factory carbs from authorized dealer? If not, they're used and just as clogged and dirty as your originals.

  • Did you completely disassemble carbs down to every last single nut, bolt & individual component? If it can be further taken apart, do it.
  • Scrub out secret hidden passages in carb-body with PEA-based fuel-system cleaner and scrub brushes?
  • Did you ultrasonic soak everything?
  • Poke out all bleed holes in jets, emulsion-tube, carb-venturi with matching gauge soft copper wire?
  • Micro soda-blast everything before re-assembling?
  • Replace all rubbers: float-valves, pilot-screw O-rings, fuel-rail O-rings, float-bowl seals, even slide-diaphragms if needed
  • Set float-height with final wet-test to confirm
  • Sync carbs with manometers.

Any of above if not done will cause you running issues. Carb's aren't "easy", send them to pros with decades of experience customcarbservices.com, Professional motorcycle carb cleaning . Guaranteed to have your bike running like brand-new off showroom floor! :)

Also how is fuel-pump wired? Driven by proper fuel-pump relay? Or just generic on/off relay or worse, on/off switch? Fuel-pump relay is pulsed by ignitor, which then pulses pump. So pump DOES NOT RUN until engine is spinning!!! The faster engine spins, the more ignition pulses per second and more fuel-pump relay pulses to pump which flows more fuel. This allows pump to vary its output to tiny bit at idle/low-RPMs and increase volume at higher RPMs where extra petrol is needed.

Sounds like you've got both carb AND fuel-pump wiring issues.
Click to expand...
DannoXYZ said:
Did you buy brand-new OEM factory carbs from authorized dealer? If not, they're used and just as clogged and dirty as your originals.

  • Did you completely disassemble carbs down to every last single nut, bolt & individual component? If it can be further taken apart, do it.
  • Scrub out secret hidden passages in carb-body with PEA-based fuel-system cleaner and scrub brushes?
  • Did you ultrasonic soak everything?
  • Poke out all bleed holes in jets, emulsion-tube, carb-venturi with matching gauge soft copper wire?
  • Micro soda-blast everything before re-assembling?
  • Replace all rubbers: float-valves, pilot-screw O-rings, fuel-rail O-rings, float-bowl seals, even slide-diaphragms if needed
  • Set float-height with final wet-test to confirm
  • Sync carbs with manometers.

Any of above if not done will cause you running issues. Carb's aren't "easy", send them to pros with decades of experience customcarbservices.com, Professional motorcycle carb cleaning . Guaranteed to have your bike running like brand-new off showroom floor! :)

Also how is fuel-pump wired? Driven by proper fuel-pump relay? Or just generic on/off relay or worse, on/off switch? Fuel-pump relay is pulsed by ignitor, which then pulses pump. So pump DOES NOT RUN until engine is spinning!!! The faster engine spins, the more ignition pulses per second and more fuel-pump relay pulses to pump which flows more fuel. This allows pump to vary its output to tiny bit at idle/low-RPMs and increase volume at higher RPMs where extra petrol is needed.

Sounds like you've got both carb AND fuel-pump wiring issues.
Click to expand...
do you have a scematic of the fuel pump wires
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chrisj32902
do you have a scematic of the fuel pump wires?
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chrisj32902
DannoXYZ said:
Did you buy brand-new OEM factory carbs from authorized dealer? If not, they're used and just as clogged and dirty as your originals.

  • Did you completely disassemble carbs down to every last single nut, bolt & individual component? If it can be further taken apart, do it.
  • Scrub out secret hidden passages in carb-body with PEA-based fuel-system cleaner and scrub brushes?
  • Did you ultrasonic soak everything?
  • Poke out all bleed holes in jets, emulsion-tube, carb-venturi with matching gauge soft copper wire?
  • Micro soda-blast everything before re-assembling?
  • Replace all rubbers: float-valves, pilot-screw O-rings, fuel-rail O-rings, float-bowl seals, even slide-diaphragms if needed
  • Set float-height with final wet-test to confirm
  • Sync carbs with manometers.

Any of above if not done will cause you running issues. Carb's aren't "easy", send them to pros with decades of experience customcarbservices.com, Professional motorcycle carb cleaning . Guaranteed to have your bike running like brand-new off showroom floor! :)

Also how is fuel-pump wired? Driven by proper fuel-pump relay? Or just generic on/off relay or worse, on/off switch? Fuel-pump relay is pulsed by ignitor, which then pulses pump. So pump DOES NOT RUN until engine is spinning!!! The faster engine spins, the more ignition pulses per second and more fuel-pump relay pulses to pump which flows more fuel. This allows pump to vary its output to tiny bit at idle/low-RPMs and increase volume at higher RPMs where extra petrol is needed.

Sounds like you've got both carb AND fuel-pump wiring issues.
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chrisj32902
what actually shuts the fuel pump off? pressure?
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D
Fuel pump controller initially primes pump for 5-sec when key ON. It doesn't need to turn off because most of time it's already off. After that initial prime, it only pulses ON briefly whenever cylinder#1 fires sparks. If pump runs continuously, you've got defective fuel-pump controller.

here's diagram for 1985 XV1000
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SemiFast
chrisj32902 said:
what actually shuts the fuel pump off? pressure?
Click to expand...
To add to information Danno provided...
Yes. Pump shuts off when pressured up but there is a time limit. If the carburetor fuel bowls are empty the pump usually will stop pumping before the fuel bowls are totally full. Turn the key switch off, then on again and the pump pumps again but begins to pump slower just before it shuts off when the fuel bowls are full. If the system is working correctly you could disconnect the fuel line from the carburetors, turn the key switch on and the pump will pump quickly then stop when it 'times out'. It's a safety thing... Like if the bike falls over or something it must shut off or possible big trouble. Nobody needs that.
Parts, even salvage parts are and pretty much always have been a headache when dealing with Hitachi I'm sorry to say.

S F
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