Fuel Pump Replacement with After Market ( ST1100 ) *

[KoTAOW]

Original article\thread can be viewed here:
http://www.st-owners.com/forums/showthread.php?89040-ST1100-Fuel-Pump-Replacement

Written by Brad Nicholson aka Draboo.

~~~

OEM Fuel Pump Replacement with After Market Pump

It was a breeze. I used an Airtex E8371 pump and a Carter STS-8 screen. Cost: around $70 for both.

There is a vent hose that connects to the stock pump. You will see it as soon as you lift the pump up. There is no clamp, just gently pry it off with a screw driver. (no pic of that..forgot the camera for the first 10 minutes)

Old Pump.

I made sure to leave plenty of wire to reconnect to if needed. The rubber sleeve needs to be reused. I found that rolling it off the old pump worked better than trying to stretch it off, less chance of tearing.

Stock Rubber Mount and the one that comes with the new pump.

You will need both.

Pump with both rubbers installed.

If you notice at the bottom edge the rubber has a rather large "notch" This goes on the bottom where the pump sits on the bracket. I reused the stock gas line because it was of a different type of matieral as the new stuff I bought, and I m guestimating the old line is meant for being immersed in fuel. I originally had the inlet and outlet of the pump towards the bottom to utilize more of the fuel, but I turned it so the connections were on top so I could use the old gas line.

Pump installed.

Make sure to get the positive wire(blue) to the + side of the pump. The pump came with crimp on connections,nuts and washers, which I used. I am allergic to the act of soldering.

Completed ready to install.

The nuts are 1/4" Like I mentioned before, I left the wires long, in case I want to reinstall the old pump.

I made sure it ran before bolting back in. After installation was complete, I jumped the pump again and let it squirt into a container. It seemed to have more pressure or volume than the old pump. I started it and let it idle, under the assumption that a leak will occur while idling,since it is using the least fuel. I didn't smell or see any leaks, but I was desensitized from the smell, so I will take it for a ride to-nite and report back.

Heres a link to the instructions I followed, it explains the vent hose I forgot to get a pic of.
GL1500 OEM Pump Replacement Instructions

All in all, a simple..hopefully permanent fix for the "hot fuel pump seizure syndrome"

© 2011 Brad Nicholson  aka Draboo, All rights reserved

~~~

Here's some more info if you shop at a part-number challenged place like Advance Auto Parts:

The E8371 pump has applications for:
HONDA ACCORD DX (1986 - 1989)
HONDA ACCORD LX (1986 - 1989)
HONDA PRELUDE 2.0 S (1988 - 1990)

The STS8 strainer has applications for a lot of GM, Honda, and Toyota vehicles, so I will include only those that use the same pump above:
HONDA ACCORD DX (1986 - 1989)
HONDA ACCORD LX (1986 - 1989)
HONDA PRELUDE 2.0 S (1988 - 1989)

You can use any of these as applications if asked.

Advance Auto does not carry Carter brand parts, but they do carry Bosch and Airtex, so I crossed over the STS8. The Airtex part # is FS9, Bosch is 68003.

The total shipped was $64.37 at Advance (for the Bosch filter & Airtex pump with a 15% discount on their site) or $64.74 shipped at Rock Auto (Carter filter & Airtex pump with a 5% discount code you can Google). The Rock Auto total dropped to $55.66 by using the Airtex filter (lower cost & less shipping from the same warehouse vs. 2 warehouses).

~~~

The next issue discovered was the 5/16 fuel hose in the tank. I did some research, and the line needs to be SAE spec J30R10. Most rubber fuel hose the parts store sells is 30R6 or R7, which is not rated for immersion in fuel. There are some alternatives like Viton or Tygon, but they end up costing as much as the 30R10 when you get the correct size and O.D. The 30R10 hose can be found as Gates # 27093 or NAPA H209. It runs $17/foot for the Gates (Amazon) to $29/foot at NAPA online.

[KoTAOW]

Update from LT Rider who just did the Fuel Replacement:

It's in and works fine, but I haven't tested it in the real world, just the garage. Anyhow..here are some pics that show how my instal varied from others.

First, someone farkled two vent hoses into the tank. Venting appears to be a non-issue on this bike. You can see them inside the tank and the hoses vent between the tank and rear fender under the seat. Interesting. If anyone knows about this farkle or has input/background, I'd like to know more about it. I'm leaving it for now.

Next..I cut a small chunk out of the band that comes with the Airtex pump to make it a little less snug inside the Honda clamp so as not to fight with the small screw.

Finally, in the finished pic you can kind of see that I added two washers between the contact points of the Honda clamp to help make up the gap and prevent over-tightening it. Still, a very easy install and could be done in a parking lot if you had to in case you're thinking of buying one for a travel kit. Nothing to it.

If I have issues with it, I'll post. Otherwise I need to go ride.

Thanks all.









~~~

Issue:

Be sure to change the hose when you have it apart. My test ride was perfect but it wouldn't start the next day. Inspection revealed the hose had broken at the bend where it exits the pump and heads north. New hose. New hose. New hose. Next?

[KoTAOW]

Comments by Norm Keller, STOC #8030:
Nice job on the pump install and report. One point which may be of interest is that I have serviced several ST1100 fuel pumps and have found the problem to be simply deposits on the brushes and commutator which limited motor current. A typical "failed" or poor performing pump has a current draw of about 0.6 - 0.7 amps while a new or properly performing pump has a draw of about 1.2 amps. After cleaning, the poor pumps showed current draws of 1.2 amps and worked 100%. Disassembling these pumps is no problem for an experienced tech. but requires care and consideration. I posted a how to on My-Mc a year or two ago if memory serves. Next pump I encounter with problems will get a treatment of strong Sea Foam in a container and some running time to see if the Sea Foam will clean the commutator & brushes. If not, I'll try injector cleaner and then a lacquer thinner mix if the first two don't to the trick. It would be useful to find a means to clean these pumps without disassembly as disassembly is beyond most hobby wrenching.

Anyone happen to have a poor/non-performing pump they will donate as I haven't had one into the garage in quite a while now that I want to try another solution?

~~~

Comments by John OoSTerhuis, STOC #1058:

First, someone farkled two vent hoses into the tank. Venting appears to be a non-issue on this bike. You can see them inside the tank and the hoses vent between the tank and rear fender under the seat. Interesting. If anyone knows about this farkle or has input/background, I'd like to know more about it. I'm leaving it for now.

My guess is that's from an aux tank install, since removed.  Does it allow the tank full-time ambient air pressure (no pressurization or vacuum)?  I'd probably cap them if they're not and let the fuel cap do its job...