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Fuel Pump Issue

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bongobobny

bongobobny

Posted
Posted

No, the points on the fuel pump are under the black cap on the fuel pump end. They make and break causing the pump to actually, well, pump!!

 

The relay supplies the operating voltage to the points when the key is first turned on for less than 5 seconds, and then continuously after the engine starts...

bootjack

bootjack

Posted
Posted
No, the points on the fuel pump are under the black cap on the fuel pump end. They make and break causing the pump to actually, well, pump!!

 

The relay supplies the operating voltage to the points when the key is first turned on for less than 5 seconds, and then continuously after the engine starts...

 

So what is causing the points to open and close?

bongobobny

bongobobny

Posted
Posted (edited)

The physical movement of the diaphragm I believe...

 

When you turn on the key, you hear a click click click. That is the points opening and closing, NOT the fuel pump relay turning on and off...

 

Keep in mind we use an inline fuel pump that uses a plunger, not an electric motor such as usually found inside a car gas tank, which generally uses an electric motor needed for higher fuel pressures for fuel injection. Our fuel pumps are more akin to the old mechanical fuel pump that used a push rod driven by a camshaft lobe to do the pumping. the Venture is carburetted which uses a much lower operating pressure...

 

Pull the left side false battery cover from your RSV and locate the fuel pump. There you will see a black cap with a screw to remove it. Remove the cap and you will see the points...

Edited by bongobobny
bongobobny

bongobobny

Posted
Posted

Perhaps this image will help you understand...

 

http://www.globalspec.com/ImageRepository/LearnMore/20122/fuel%20pump%20diagramb28f6490842c485394ecf10695bece1c.png

 

Electricity is supplied to the electromagnet which pulls the diaphragm. This causes the contact points to disconnect, causing the spring to push the plunger back out. This causes the points to reconnect sending electricity back into the electromagnet causing the whole process to start over again...

bongobobny

bongobobny

Posted
Posted

Perfect, Jack!!! Now, do you have a picture of the Fuel Pump relay?? I could probably crop the fuel pump relay circuit and paste to explain its operation for the guy...

bootjack

bootjack

Posted
Posted
Perhaps this image will help you understand...

 

http://www.globalspec.com/ImageRepository/LearnMore/20122/fuel%20pump%20diagramb28f6490842c485394ecf10695bece1c.png

 

Electricity is supplied to the electromagnet which pulls the diaphragm. This causes the contact points to disconnect, causing the spring to push the plunger back out. This causes the points to reconnect sending electricity back into the electromagnet causing the whole process to start over again...

 

Thanks! I was thinking of electric motor type pump with some sort of impeller...

 

Now the next questions...what are the specs on the OEM pump...psi and GPH...I don't see those listed in the service manual. Has any one done a bench test to determine this?

 

My bike has been sitting for a few months (long story), and when I went to start it up last week, the normal clicking from the fuel pump was not heard when kill switch was turned off and bike would not start....tried the next day and the clicking was there and bike fired up normally after gas got pumped up to carbs. Bike has 88,000 miles and never had a problem like this, so a bit apprehensive of going out for a long ride till I check it out.

 

Thanks again for the extra info !!

Condor

Condor

Posted
Posted
Perfect, Jack!!! Now, do you have a picture of the Fuel Pump relay?? I could probably crop the fuel pump relay circuit and paste to explain its operation for the guy...

 

Sorry.. Can't help you there Bob. I do know that the pressure is controlled by a center post/interrupter rod. As the lines come up to max pressure the diaphragm doesn't compress, rod holds the points apart, and the pumping stops. As the pressure in the lines drops the points close and shazam the coil fires and the diaphragm cycles until the pressure returns to specs. And so on.... Kinda a rinse-lather-repeat operation... :pushups:

bootjack

bootjack

Posted
Posted
So normally just the points go "out", what happens to them? Would a standard points cleaning every 20K miles or so be helpful? Should they have a condenser across them? was it left out for "economy" or packaging?

 

Good idea...IMHO.

bongobobny

bongobobny

Posted
Posted (edited)
Good idea...IMHO.
Yeah, stuttering Gary's head is more than just a hat rack...

 

Somewhere, in some thread here, is the specs you are looking for. Sorry, but I don't have them handy. This is a timely question though as I am considering buying one of those aftermarket ones that have close to the same specs and has the shut-off feature. Our bikes are carburetted so the psi should be around 10. Not sure of the flow rate but remember that when the carbs are full, the needle valve closes and no more gas gets in, resulting in a pressure build up on the inlet line which results in the pump eventually not being able to pump more...

Edited by bongobobny
bootjack

bootjack

Posted
Posted
Yeah, stuttering Gary's head is more than just a hat rack...

 

Somewhere, in some thread here, is the specs you are looking for. Sorry, but I don't have them handy. This is a timely question though as I am considering buying one of those aftermarket ones that have close to the same specs and has the shut-off feature. Our bikes are carburetted so the psi should be around 10. Not sure of the flow rate but remember that when the carbs are full, the needle valve closes and no more gas gets in, resulting in a pressure build up on the inlet line which results in the pump eventually not being able to pump more...

 

Timely for me too.....I ordered points today and may opt for the Facet, or something similar, later. Over $200 for OEM is a bit too much I think...

 

If you come across the OEM specs post them please....

KevinR

KevinR

Posted
Posted

 

According to all I can find about this part number, it doesn't fit any of the RSV's or TD's. 2 different sites, including the link first showing these points say this part is a no go. Are they wrong?

Leland

Leland

Posted
Posted

According to the service manual, the stock fuel pump is a Mitsubishi 4NK with an outlet pressure of 15~20 kPa = 2.2~2.9 PSI. The Facet 40178 is rated for a max of 3.5 PSI, min of 2.0. This is the one that I used. I took a 1500 mile trip to the Black Hills with it a couple of weeks ago with no issues which included 200 miles of 75-85 MPH interstate.

Condor

Condor

Posted
Posted
According to all I can find about this part number, it doesn't fit any of the RSV's or TD's. 2 different sites, including the link first showing these points say this part is a no go. Are they wrong?

 

YEP!!....

bootjack

bootjack

Posted
Posted
According to the service manual, the stock fuel pump is a Mitsubishi 4NK with an outlet pressure of 15~20 kPa = 2.2~2.9 PSI. The Facet 40178 is rated for a max of 3.5 PSI, min of 2.0. This is the one that I used. I took a 1500 mile trip to the Black Hills with it a couple of weeks ago with no issues which included 200 miles of 75-85 MPH interstate.

 

Well crap...missed seeing the specs when I was looking in my manual the other day....just went out to garage and slowly reviewed spec sheets and there it was! Flipping pages too fast I suppose. Thanks!

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