Page 5 of 6

Posted: Sat Sep 13, 2008 7:15 am
by postrucks
I was able to rebuild my pump thanks to peteybug's illustrations. I used a small block chevy fuel pump for the "donor" diaphram. Went to the local auto parts store and told them I wanted a fuel pump for a 75 chevy pickup, and $20 later....My first attempt it leaked out the weep hole. So I took it apart and cut a gasket out of the left over diaphram material to go under the screw head also added a thin steel washer to prevent distortion. Works like a champ.

Posted: Sat Sep 13, 2008 8:08 pm
by peteybug
Glad to hear that. Good luck.

Posted: Tue Oct 28, 2008 11:56 pm
by Roj
BUDKING wrote:i found a small electric fule pump that puts out 2-4 psi and stated it was for 4-6 cyl cars its kinda rigged on the bike atm just to see if it will work out ok so fare its doing just fine and it isnt very loud $44 But i would like to fix my old pump a new one is $92 bucks+ tax. So how much for a pre cut pice of rubber.
Man I wish I could get a pump for that cost, I am in New Zealand and I was quoted NZ$540 for a replacement, just been reading this thread to see about fixing my one...

Posted: Wed Oct 29, 2008 12:05 am
by Cookie
That should be doable. You might even find the material over there. If not a fuel pump from something like a Holden should give you the material.

Posted: Wed Oct 29, 2008 3:13 am
by Roj
Cookie wrote:That should be doable. You might even find the material over there. If not a fuel pump from something like a Holden should give you the material.
Yep, I was thinking of hopping in to shop to talk to someon I know that might be able to help

Posted: Wed Oct 29, 2008 11:45 am
by Cookie
I've always been able to get much more rebuilt in Kiwi than over here. In the old days repair parts were hard to come by over there.

Posted: Wed Dec 24, 2008 11:17 pm
by hiddenone
good work but more than i want to do. I bought an electric fuel pump for about $35 and it worked great. as for the whole where the old pump went i just made a blank cover for it and bolted it on. :)

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Fri Jul 23, 2010 10:30 pm
by Sidecar Bob
A few weeks ago I got thinking about this. My 'Wing is now pulling a sidecar (= burning about 20% more fuel) and the pump is drawing from the Rotopax mounted on the side of the sidecar by the saddlebag about 40% of the time (significantly farther away from the pump than the bike's tank and lower so it won't syphon if the pump dies). I figured it was about time I did something to make sure I didn't end up stranded by a dead fuel pump so I started searching eBay for a fuel pump diaphragm that might be useful (or a kit that contains one).

I found several that looked promising but the only one that had a diaphragm that was usable was a kit made for a 1929-1933 Chevy offered by a seller called Marxparts. The listing said "This is a Fuel Pump Gasket Set and Diaphragm for a 1929-33 Chevy fuel pump. It includes modern neoprene diaphragm that handles today's fuel types, 3 bolt spring cover gasket, glass fuel bowl mounting gasket, and fuel pump engine mounting gasket" I contacted him to ask about the dimensions of the diaphragm and told him what I wanted it for. He told me that the diaphragm is 3 1/4" (approx. 82.5mm) diameter with 3/16" holes. The measurement from the inside of one hole to the inside of the opposite hole is 2 1/2" (approx. 63mm). He also told me that they sell the diaphragm separately for $6 + shipping ($4 to Canada).

The diaphragm for a GL1000/1100 pump is 68mm diameter and the clamping diameter is 45mm so I ordered one.

I finally got time to mess around with it today. I did everything pretty much the way Peteybug described except for a couple of things:
- I took the pump apart to work on it. Instead of drilling the ball bearings out with a carbide bit as has been described in another thread, I drilled a couple of small holes just inboard of the balls and at an angle and drove them out with a small drift. This allowed me to clamp the shaft in my drill vise for drilling &c.
- I held the top of the pump against the new diaphragm, centred it by eye (the original holes will be a bit less than half exposed) and marked the new holes and the outside diameter with a ball point pen, then punched the holes with a leather punch and cut away the excess with sharp scissors.

Now I need to get time to mount it on the bike and try it. I will probably carry my old but known good pump with me for a while just in case.

I will report back after I have had it on the bike for a couple of weeks.

If you want to order one of these diaphragms, go to (last item on the page) or email and tell him you want a 3/1/4" fuel pump diaphragm like he sold Sidecar Bob

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Sun Jul 25, 2010 8:56 am
by peteybug
Bob thanks for the info I think I'll get some and try them. Thanks again Pete

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Sun Aug 01, 2010 8:24 pm
by Sidecar Bob
I put the rebuilt pump on today, started it up and it squirted fuel out of the weep hole. Then I took it back off and opened it up again to see if the screw had come out or something dumb like that but everything looked OK.

While I was in there it occurred to me that the washer I had put under the head of the #6 screw was a lot smaller than the one I destroyed taking it apart so I dug around and found a larger outside diameter washer, put it all back together and tried again.

I don't know if the washer made any difference but this time it didn't squirt so I went for a test drive around the block (10 Km - we have big blocks here) and it didn't squirt even after running for half a Km at 5000 RPM. I know it was pulling fuel uphill because it was drawing from the Rotopax and, while the carb bowls are a bit higher than half way on it, it was less than 1/3 full. Also, I could see the bubbles moving in the fuel lines and filter.

So far so good, but I think I will carry the old pump and the tools to swap it out in the saddlebag for a week or so just in case.

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Sun Aug 01, 2010 9:28 pm
by Cookie
Good on ya Bob!

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Sat Aug 20, 2011 5:53 pm
by Sidecar Bob
After more than 6200 Km the pump with the Marxparts diaphragm is still working perfectly.

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Wed Dec 07, 2011 1:17 pm
by RB
Guys I have done this too, several times and I have a local source for viton to make the gasket. Works well.

Some issues not mentioned the shaft can spin when drilling and/or you have to have a way to hold it, I made a jig to compress the shaft/metal disk that holds it in place or you can use some needle nose vise grips to hold it.

Second getting the metal plate off can end up bending it a bit so you have to be sure to get it perfectly flat again or it may leak. Also better to use a flat/pan head bolt round tops tend to hit the top of the pump. And you should use a drill press to drill it out not much room for error when drilling the shaft.

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Sat Jun 23, 2012 4:49 pm
by lambretta
Yes, I need a new pump :( . Fuel below the diaphragm must not be. There must be a hole in it.

Re: Fuelpump rebuild gl1000 (It worked)

Posted: Sat Jun 30, 2012 9:25 am
by Sidecar Bob
Almost 2 years and the Marxparts diaphragm is still OK.

If you need one they are on this page (last item at the bottom - still $6)