Fuel pump repair on a '82 XZ550RJ

[pat sullivan]

I've had some symptoms of a weak fuel pump, mostly when the engine is very hot, so I ordered a Keyster overhaul kit from Sirius. 

I've got the pump apart now and there is not an obvious visual problem.  The two large transparent diaphrams are not cracked or broken but they are somewhat rigid, especially the one connected to the maniford.  The two smaller transparent disc valves look OK.  The rubber pressure regulator diaphram doesn't look too good but there are no obvious holes or tears in it. There was not a replacement for the regulator rubber diaphram in the Keyster kit.  I wish there was, I would replace it.  In addition to the gaskets, two diaphrams and two disc valves, the kit has two very small disk valves. 

I've got three questions.

1.  Is there someplace where I can get a new pressure regulator diaphram?  Or get a new fuel pump?

2.  What are the two very small discs for?  Where do they go?

3.  Is it likely that just replacing the diaphrams will correct the problem?

Thanks,

Pat S.

[jasonm.]

You can stop screwing around with that rubber pumper ...look here... this is what I use.
http://cgi.ebay.com/ebaymotors/OEM-Yamaha-VX1000-VX1100-Virago-Fuel-Pump-1984-1999-/190425832263?pt=Motorcycles_Parts_Accessories

or this
http://cgi.ebay.com/ebaymotors/YAMAHA-VENTURE-ROYALE-XVZ-12-13-FUEL-PUMP-/280535329224?pt=Motorcycles_Parts_Accessories

[vadasz1]

@jasonm.  With the electric fuel pumps, do you still use a manual petcock or have you ditched it?

[Tiger]

 :) This one, that Jasonm put up, is done... :o

http://cgi.ebay.com/ebaymotors/YAMAHA-VENTURE-ROYALE-XVZ-12-13-FUEL-PUMP-/280535329224?pt=Motorcycles_Parts_Accessories

...thanks Jasonm ;)

           8).......TIGER....... 8)

[johnclemens]

I have used these Facet fuel pumps for years on all kinds of bikes as well as my racer.
You just have to be sure you get the low psi version. 2-5 psi.
The only problem with electric fuel pumps is if you have marginal needle and seat in your float bowl. You may see dripping under your bike from the carb overflow tubes.
You can get these pumps at your local auto parts. much cheaper than jap bike stuff.
John
http://cgi.ebay.com/ebaymotors/Facet-electric-fuel-pump-_W0QQcmdZViewItemQQitemZ170495366290QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_624wt_935

[jasonm.]

I am presently using a Virago 535 fuel pump. The Venture is slightly better for 2 reasons. The right angle spigots are stronger then the straight ones on my 535 and the Venture has a safety shut off. If it runs for 5 seconds constant ,,,it shuts off. This is in case your fuel line breaks or float sticks. If your carbs are empty from sitting you just have to turn off on a few times. I can run mine on prime if I choose. These Yamaha pumps run about 1-3 psi. Also there are some newer ones that are 5/16 spigot. You want 1/4".These  pumps don't leak when they're not running...

[inanecathode]

I have used these Facet fuel pumps for years on all kinds of bikes as well as my racer.
You just have to be sure you get the low psi version. 2-5 psi.
The only problem with electric fuel pumps is if you have marginal needle and seat in your float bowl. You may see dripping under your bike from the carb overflow tubes.
You can get these pumps at your local auto parts. much cheaper than jap bike stuff.
John
http://cgi.ebay.com/ebaymotors/Facet-electric-fuel-pump-_W0QQcmdZViewItemQQitemZ170495366290QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_624wt_935

+1 on the electric pump. I havent converted the bike, but i did do my beetle. I found the 5psi rating they claim to be a bit low, i ran without a regulator thinking i was alright until it flooded out completely. I did a pressure check and the facet pump was putting out 9psi instead of a max of 5psi. Good thing is, low pressure regulators (when you can find one) are pretty cheap.

[pat sullivan]

Thanks to all who responded. 

I rebuilt the fuel pump using the Sirius kit and the problem appears to be corrected.  The problem was apparently in the one large diaphram or the valves when they were hot.  The very small discs are spacers under the valves to ensure the 0.005 inch clearance required in the static position.  I didn't realize this until I actually disassembled the valves.  FWIW, installing the new valves is a very intricate operation and I would not recommend removing them unless you have new ones in hand.

John and Jason.  The possibility of using an electric pump is an good suggestion (why didn't I think of that?).  I probably would have gone that route except that I had the kit in hand and I was able to get back on the road right away.  The Sirius kit does not include the regulator diaphram so that's another advantage of having all new parts with the electric.

Pat S.   

[jasonm.]

Hope for you all works well with the stock pump now . In case it does not...  Remember the electric ones are extremely durable. My '87 Venture has the original pump and it has 75k .

[Hartless]

so if im correct. .... no one knows where to get a new pressure regulator? i dont want to switch to electric. at least not yet