Fuel Pump Question

[dkaiser]

Hello All,

 

Iam getting my carbs in shape on my '87. In the process of cleaning, testing etc., I wanted to make sure the floats and needles seem to be working right so I took each carb, put it in a shallow tub and hooked it up to the fuel pump on the bike, with the float bowl cover off, to see that the float would, in fact, float an shut fuel off.

 

OK, I assumed the the fuel pump would just pump, and pump until the float shut the fuel off. Is there any reason why I would have to turn the key off, and then turn it on again to get the pump to pump a little more. It will pump for about 5 seconds and then turn off, until I turn the key off and then turn it on again.

 

If this is a normal function, maybe a safety feature since the bike is not running or something than all and well, but if there is a problem with the fuel pump, or something, I just wan to know.

 

Thanks a bunch

 

D

[Squeeze]

Hi,

 

that's a normal Behaviour of your Fuel Pump. Seems to be an Safety Issue.

 

btw, very good Idea, so, you can check the Float Valve AND check the Float Level without the Hassle of taking them in and out, dismount, put them in and out again ...

[fixit3546]

You can just cycle the kill switch on and off, it has the same effect.

 

I like the idea of a pre-check too.....................

[dkaiser]

Yup, it works pretty well and I can see that the valve shuts off the fuel and that the floats, float.

 

Now I will put the carbs together and on the bike.

 

D

[Squeeze]

Hey, i don't doubt that ...

 

 

Did you check and adjust the Float Hight ?

[mbrood]

As I understand the operation...

 

Turning on the ignition switch puts a five second signal to the pump (this is renewed when turning it off and back on OR cycling the kill button.

 

Then the pump times out and is OFF.

 

Once you hit the starter button... the engine turns over and the number two cylinder ignition pick-up sends a signal to the TCI, The TCI sends that pulse to the spark coil, the tach AND the fuel pump... each new pulse triggers the pump, keeping the fuel flowing.

[dkaiser]

Thanks for the explanation