Replacing your fuel pump

[MSGT-R]

Sometime sooner or later, the mechanical fuel pump on the GL1100 is going to give up the ship. Mine started to leak out the weep hole on our last trip.

Leaky pumps leave residue

Thanks to Honda Parts Direct, I had a new pump and gas cap (the vent valve was stuck too) to put on the bike this morning. Fuel pump was $78.39 and the cap was $22.91

New parts from Honda Parts Direct.

Taking off the fuel pump is pretty straight forward since it hangs off the aft end of the right cylinder head. Rather than take the two 12mm bolts off the "neck", take the whole assembly off at the head (10mm head bolts) the inboard bolt also holds the tachometer cable in place.

The 12mm head bolts hold the pump to the neck. There is a black spacer in between the two, and that is needed to put everything together again so don't damage it. If it's stuck, use a gasket scraper rather than a screwdriver to pop it loose. When you order the pump, order the gaskets too because they don't come in the box. Carefully use a razorblade to scrape all the old gasket material off to leave clean flat surfaces for the new gaskets.

Putting the pump back on is a little different than taking it off. The pump arm runs off an eccentric that is a part of the end of the camshaft (the worm gear for the tach cable is there too).

Use Lithium Grease

Grease everything before assembly, because there is no oiling coming from the engine in this area. Put the neck piece on and rotate it towards you to make the pump easier to mount.
Note: the o-ring you see on the tach cable end is my idea, not a Honda part. I did it to keep the weather out of the area above the drive seal. If you do it, the o-ring needs to be skinny enough for the bolt to pass by it.

Housing install

After mounting the pump to the neck piece, you can rotate the assembly into place to line up the bolt holes. Put in the outboard bolt first (finger tight) to hold everything together. Insert the tach cable into its hole, then put the inboard bolt in to finish. If the tach cable won't seat, it's because the blade isn't lined up with the mating slot. Use a small screwdriver to turn the cable slot to align.

Rotate for mounting

You are now free to hook up the fuel lines again. Test n' Check before heading out of the garage on a ride.

What caused all this was the gas cap. The tank vents through the cap and nowhere else. If the vent in the cap goes bad, vacuum builds up in the tank to the point of stopping fuel flow. This will probably happen when the tank is almost empty and there is a large vacuum above a small amount of fuel. This happened to me when switching to reserve, and Murphy's Law dictates it will happen out in the middle of nowhere.

The new parts photo from Honda Parts Direct included a gas cap. This is a supercession to the original, but it fits.

Notice the different bottom

The new is shallower too.

To get me though the remainder of the trip since we were 1100 miles from home, I drilled a small hole through the top of the cap as a temporary measure, but this new cap is better for a permament repair.

[donagh]

one question what is the weep hole, is it the tiny hole on the side of the fuel pump. Also when I dismantled the pump today, the area where the worm gear is had oil in it, from ready the instructions there should be oil in here that is why you suggest lubing with lithium grease.

btw - new user and owner adn this site is fantastic.

[MSGT-R]

There is no engine oiling supplied to that area (like an old Chevy). When I took my old one off, there was no oil or grease. The new one was dry also. Packing it with lithium grease will do no harm since the area is mostly sealed, the grease will prevent the metal parts from wearing down quickly. Grease will stay in place better than oil in the long-run.

[SyLord]

Although you say no oil gets up there, can fluids from up there get to the oil?

I just bought my first Gold wing and the fuel pump gave out on the previous owner. He parked it unable to afford to fix it, so I rescued it from sitting there forever.

I know the fuel pump is bad, but the oil smells of gasoline also. Can a gas leak then also get into the oil from the fuel pump?
Part of the question just leads me to wonder what grease or lubes I can use for the tach and fuel pump and if I have to worry about anything making it into the oil. I use some red grease for a metal lathe and bearings, and it is strong, stringy and sticky, but I wouldn't want it to get into the oil pan or sucked up into the motor...

[WingAdmin]

Although you say no oil gets up there, can fluids from up there get to the oil?

I just bought my first Gold wing and the fuel pump gave out on the previous owner. He parked it unable to afford to fix it, so I rescued it from sitting there forever.

I know the fuel pump is bad, but the oil smells of gasoline also. Can a gas leak then also get into the oil from the fuel pump?
Part of the question just leads me to wonder what grease or lubes I can use for the tach and fuel pump and if I have to worry about anything making it into the oil. I use some red grease for a metal lathe and bearings, and it is strong, stringy and sticky, but I wouldn't want it to get into the oil pan or sucked up into the motor...

Typically the most common way fuel gets into the oil is when you have both of two problems:

a) fuel petcock is leaking (doesn't turn off properly), or is left turned on
b) carburetor float valves are sticking open, allowing fuel to drip down into the cylinders when the bike is turned off

[SyLord]

...or in my case where the diaphragm rips and leaks right through the bottom.

It was replaced today and is running good now.

[MSGT-R]

Great!

Sorry for the delay, I was out..
There is a weep hole below the diaphram to let any gas go out, rather than collect in the area. It still can collect in the "neck", and eventually work it's way past an old or bad seal, but since there's no pressure in that area it wouldn't be much if any at all. Like said above, you have bigger problems elsewhere for gas in the oil.

[N2PPN]

Just wondered if anyone had done the Randakk's electric fuel pump conversion instead of the OEM one from mother Honda (16700-371-014) ..

It might not be as pretty as the OEM one, but it should prove to last longer and possibly be more reliable???

Anyone done one??


Rich

[blackwolfs8]

Another GREAT help I just had to replace the pump on my 81 gl1100 and followed this article and was done and on the road for test drive before the wife thought I should have ,she thought I was just riding .Thanks WINGDOC.

[dwight007fchr]

Hello fellow Wingers. I was looking for information as to how to check to see if the fuel pump is failing. I have an 83 GL1100, and she seems to be starving for gas as I cruise down the road, more noticeable at lower speeds (30-45mph), and not as much at higher speeeds.....say 60-70.

I was getting that "vacuum" rushing sound when I took my gas cap off, and I cleaned it out with WD40, and then used compressed air in the holes, while pushing the spring from closed to open, and I thought it was working. But the other day I turned the gas top to put gas in, and there was still a small vacuum sound of air rushing in. So, I thought the missing/fluttering was due to the pressure building up in the tank, and the fuel pump being unable to deliver enough gas to the carbs, and I left the fuel cap loose, and just lying on the tank and tried another test drive......but she still ran poorly, with alot of fluttering going on. So, I suppose a clogged up tank top can cause the fuel pump to go bad?????

Now, I want to test the fuel pump........so, is there any test that I can do to see if the pump is working?

I also wonder why a pump is needed since the gas tank is above the carbs......gravity wont deliver the gas fast enough?

Many thanks.

[dwight007fchr]

Here are some pics of the fuel pump as removed from my 83 GL1100. The first pic shows some oil pooling in the chamber after I removed it. (Someone else above mentioned having oil here also, and I am wondering if Honda adds some from the factory, or if some slips by the cam shaft and enters the pump area......anyone know?)
Also, the speedo cable does not seem to have any gastket to keep water out of the gear/cam shaft portion of the fuel pump.....seems that water can just slide right down the cable and into the fuel pump gearing chamber. The next time I take it off, I am tempted to add a tight fitting rubber washer around the speedo cable (at the top where it meets the fuel pump housing) which will shed most water drops. Who knows, maybe that "oil" we saw in the chamber was just water that mixed with the old grease on the gears, or spray lube coming down the speedo cable from a wise owner spraying lube at the top of the speedo cable. A real mystery.

Fuel Pump off, with a bit of oil pooling inside

This pic shows the diaphram after removing the 5 top screws and prying apart:

Top half of pump opened up showing diaphram

Then I sprayed some lube in the air hole to be sure it wasnt clogged.....with some bee/spider nest.....all clear.

Spraying some lube into the hole to make sure it was not clogged up

Can someone explain what the black diaphram is for as shown on the lower right of this next picture? This is on the very top most of the fuel pump, above where the inlet and outlet gas lines are.

Inside the top portion

I had a bit of semi-hard gum lodged inside the fuel pump, but probably not enough to cause any issues. Took the bike for a test drive after cleaning and reinstalling (and applying the grease as suggested above), but this still has not solved my performance issue. She still wants to "flutter" or "miss" at low to medium speeds, but seems to purr fine around 55-70 mph. Looks like it is probably a carb issue.......help.

Note: I was able to install the entire fuel pump back on just using the two lower No. 10 metric screws that go into the head. I had to kinda make the engine shaft go to the lowest portion of the fuel pump, which allowed the pump follower extension to fit over the cam properly. Getting the front screw in was no issue, but the rear one with the speedo cable was a bit more challenging. Its good to slide a thin round punch into the hole to make sure the speedo taper is lined up just right or the screw does not want to go in properly....takes a bit of patience.

[greganderson]

thanks for the post.... I have a couple of questions

I am diagnosing some fuel delivery issues ( and I have cross posted this in a previous post) .....anyways, my tachometer stopped working.
I can turn it by hand,at the fuel pump end, but it is tough....do I need to oil it or replace cable?

also, what actually turns the camshaft that operates the fuel pump/tachometer? My #1 and #3 cyclinder are firing but not 'operating'- does this affect the operation of the tach/ fuel pump or is that shaft independent of the non-running cylinders? dumb question I know, but i am trying to get my head around the mechanics of this bike. (gl1000)

[WingAdmin]

thanks for the post.... I have a couple of questions

I am diagnosing some fuel delivery issues ( and I have cross posted this in a previous post) .....anyways, my tachometer stopped working.
I can turn it by hand,at the fuel pump end, but it is tough....do I need to oil it or replace cable?

also, what actually turns the camshaft that operates the fuel pump/tachometer? My #1 and #3 cyclinder are firing but not 'operating'- does this affect the operation of the tach/ fuel pump or is that shaft independent of the non-running cylinders? dumb question I know, but i am trying to get my head around the mechanics of this bike. (gl1000)

As I mentioned in this post, sudden failure of tachometer, fuel pump and #1 and #3 cylinders indicates your right timing belt has broken - along with the engine damage that will occur when this happens.

[littlebeaver]

Man alive, I didn't know to grease the gear there for the tach gear ..... Wow thanks for the post on that. Wow So good to know this...Wow Seriously I am greasing it like tomorrow...I didn't catch that in the manual....

[dwight007fchr]

Sylord made a post a few years ago that gas was getting into his crankcase oil, and from what I read, no one said it was possible for alot of gas to bypass the fuel pump and go straight into the crankcase. WingAdmin said it most likely was due to stuck carb floats and the gas was pooling in the cylinders and then going into the crankcase.

I started a new thread a few days ago, and have been waiting for comments, but I suppose most people are busy or on vacation. My issue is that I had the GL1100 running with a half gallon of gas rigged up beside the fuel pump. I just put the rebuilt carbs back on, and just put fresh oil/filter on the bike. There was no way gas could have been in the oil before I cranked her up. With the bike running only 5-10 minutes while doing carb syncs, I discovered that over a half quart of gas had made its way into the crankcase. This could not happen from the carb, as the engine was running. So, alot of gas was being diverted to the crankcase from the fuel pump. From what I can tell, this is what happened to SyLord

Has anyone else had alot of gas enter the crankcase via the fuelpump??

Thanks.

[randall_l_davis]

I have a 1983 gl1100 and I could not figure out how to get fuel to the carbs. I thought it was the fuel sending unit. There is a small gasket check valve in the IN port of the unit and mine was gummed up from old gas that had been sitting in it for 15+ years. I blew a little air in it until it popped and I was able to free the check valve. I sprayed some carb cleaner into it and it works just fine. Hope this info helps someone. I figured that out by logic and luck. Thanks.