Fuel Pump Test

[blueyedjack]

Hello, I am a new owner of a 77 GL1000. It currently has an electric fuel pump on it which was installed by a previous owner. The stock fuel pump is abandoned. I would like to get this bike back to as original as I can. My question is - how can I test the stock pump to see if it works? I don't know if it failed sometime in the past and that is why the electric pump was installed or the electric pump was added because it might be more efficient. If anyone can give me a few suggestions, it would be appreciated. I have thought about just reconnecting the stock pump and seeing if the bike will start, but don't want to damage anything should this be the wrong procedure.

I have already learned a few things by reading this post. The information is great.
Thanks
Blueyedjack

[dingdong]

Your best bet is to open up the old pump and inspect the rubber diaphragm for cracks or holes. There is a test where you remove the outlet hose and pump fuel into a container but I don't remember the specific volume.

[spookytooth]

Get some plastic fuel line. Connect one piece to the in and one to the out of the mechanical fuel pump. Get yourself a coffee can and put some gas in it. Start the bike up and let it idle. Dip the hose connected to the pump input in the gas and see if it pumps. If it does, pinch off the outlet hose to see how much pressure it will build. If it seems good, let it run for a while just pumping fuel through the pump to clean it out. Hook it up and ride away.

However, I honestly can't see someone unhooking a perfectly good mechanical pump and installing an electric one. Folks usually wait until their pump fails to replace it.

[blueyedjack]

Thanks for the suggestion. I may give that a try. I downloaded the manual for my bike from gl1000.info so I'll do some studying of the pump also.

[Placerville]

I think it's a good effort to get your bike back to a factory look. However, if you're dead-set on using the old pump (and not a new one), do this:

First, test for the rate of fuel flow:

Disconnect the 'carb-side' fuel line from the pump and plug it. Attach a new line to the carb-side of the pump and run the other end into a measuring device. Start the bike and let it run on the existing fuel in the carb bowls. The fuel flow rate should be about 15 oz. per minute at 3,000 rpm.

Next, test for pressure.

To test for pressure, remove the temporary line and, before you reinstall the original, place a T in the line. At the T, you should get 2.4 PSI at 500 rpm, 2.3 at 900 rpm and 2.0 at 5000 rpm.

My advise is to buy a new pump. Used/old pumps are nothing but trouble waiting to happen. Here's the best price you'll find. While you're at it, don't forget to change the insulators (#1 & #6) and the tach oil seal (#31). When replacing the oil seal, apply a small amount of Permatex on the bottom surface because (at times) they don't seal even when they're new. Push the seal firmly into place using a small socket.