65 mph maximum attainable speed

1996 R1100GS. About 80,000 miles. Not sure exactly the total because the speedo broke in Peru.

In March I rode it from Wisconsin to LA and back, with three 1000 mile days, and the bike was perfect. The last day was 970 miles in 13.5 hours.

A week later, the bike was rough to start. It would dog/bog down a little, but once warmed up, it went fine around town.

Sunday, I rode it from Madison to Minneapolis. It was about 45 and rainy when I left. It took about 40 miles before the bike warmed up. It kept doing a new, "skipping" type of thing. I figured it was because it was cold.

(In an un-related act of stupidity, I got nailed for passing a truck and a semi in a double-yellow, $215.)

After about 200 miles, I noticed that it was hard to go 80 mph. I wasn't getting the normal zip. I wondered if the snorkel pre-filter was wet and clogged, because it had been in the snorkel for the last 5000 miles. I stopped at a gas station and pulled it out. The pre-filter was dirty, but after removing it, there was no change.

At 2:00 this afternoon, I put 8 gallons of fuel in, and I started for home. 5 miles later, the bike almost quit on me. I had been going about 65 mph eastbound on I94, just west of Saint Paul.

I was able to get off the highway. The bike quit. I was able to re-start it.

I called GS Diablo. He invited me to his house. I was able to get the bike to limp there. It wouldn't idle, and 40-50 mph was the fastest I could go.

We changed the fuel filter. The fuel pump seemed to be pumping tons of fuel- enough to squirt at least a few feet. Compression was good on both cylinders. We changed the spark plugs anyway. All the hoses seem to be tight.

GS Diablo is also a GS rider. We're both mainly riders- not mechanics- but we're not total idiots (well, he's not, but I probably am).

GS Diablo offered to lend me a 650GS to ride back to Madison, and then come back for the pig with my truck, but I decided to ride it home. I limped home. At 65 the bike would bog down. I'd down-shift to 4th, then 3rd. The bike would run smoothly, and then I'd try to shift back up. I could ride it at at 65 if I constantly feathered the throttle. 300 miles of constantly feathering the throttle pretty much wore me out, but the bike got me home.

What's wrong with it?

ps: GS Diablo is fucking AMAZING. One phonecall, and he took off from work to help me. Within 20 minutes I was filling every plastic jug in his house with gasoline. If you've ever tried draining an 11 gallon touratech tank, you know what I'm talking about.

By "a few feet" how far would you guess? !0 feet or two feet? You want about 40 psi of fuel pressure which should give a nice jet of fuel. Was the tachometer acting funny? If so, it could be the sensors for the injection and ignition under the front cover or the wiring for them. That is usually a go/no-go issue though. It first starts to show up in the rain which you experienced. Hmmm?

Take a look at the throttle position sensor. Make sure it is adjusted correctly.

I'm a completely zero on this, but aren't these symptoms those you see with a burned valve?

[TaSK]

"Compression was good on both cylinders."

Good guess but a burned valve would have bad compression, and similar symptoms.

Sorry - missed that.

[TaSK]

I was going to scream "fuel filter" but you covered that so you might want to test that fuel pump with a pressure gauge.
That is where I would start maybe.

My first guess here would be a fuel pump, had one go out on me a while back, gave similar symptoms, what you describe is a little milder than what mine did... but still an option I think. Best of luck.

Why not try to check for electric error codes? It's simple and fast

Dan.

Are those the symptoms of a bad Hall sensor?

Bad Fuel?

http://advwisdom.hogranch.com/Wisdom/oilhead_hall_sensors.pdf

Another inmate here had the same symptoms a while back. Turned out to be a fuel pump that was putting out about half the pressure that it should. Hard starting and no top end.

Put a fuel pressure gauge on it. Should be around 40lbs I think.

Thanks for the ideas.

In the next few days I'll tackle the throttles. My gut says the problems are in the throttle. You know how you can bump that little cable and make you think the motor is wrecked? That's what it feels like.

If that doesn't work, I'll truck it to Mischlers BMW in Beaver Dam.

As hard as yesterday's ride was, my bike got me home. While we were trouble-shooting, for a little while we ran the bike on one cylinder. I'm certain that if I had been in the middle of nowhere, it would gave gotten me home on one cylinder.

A non-rider friend suggested I buy a new bike. They don't understand that this bike has been from Alaska to Argentina, and this is the first time I've had trouble.

female non rider friend You couldn't put that tank on a new bike. Good luck with the troubleshooting

Right now the tank and the piaa's are more valuable than the rest of it.

I forgot to mention that before I put the fuel-pump assembly back in, I deliberately bent the float-arm. The 11 gallon touratech tank isn't very compatible with the stock fuel gauge.

The fuel gauge used to read "full" for the first 150-200 miles. Then it would quickly go to zero. Once the fuel light comes on, the most I've ever been able to get into the tank is 9 gallons. I've never run the bike dry. My hope, by bending the float arm, is that it'll start to come down sooner.

I forgot to bend the fuel intake. There's a trick to bending it so that sitting in the tank it'll suck lower.

The fuel pre-filter... it's a woven nylon, with a steel spring inside. Both ends were open. I stapled one end, and used baling wire to sew the other end. I don't know why it came apart.

That GSDiablo is one cool dude.

Following this thread with great interest. Must hear the outcome....

So the possible causes of the loss of top end power are:

1. Fuel Filter - replaced
2. Plugs - replaced

3. Fuel Pump starting to fail, i.e. weak stream
4. Injectors clogged, hmm not the right symptoms though?
5, O2 Sensor failing
6. Hall Sensor
7. Torn plug wires letting water in and shorting
8. ???

Don't forget the pressure regulator. While there haven't been many reports of failure, there have been a few.

JJ

Is there any chance that some of that nylon got into the fuel lines?

Sir,
If pressure regulator fails, ie pressure much too high -> very low flow of petrol, the high pressure could also lead to fuel pre-filter failure.

It didn't look like any of the nylon had come off, but I have no idea why it would have burst at both ends. Does that nylon break down over time? It never seems to get very hot... even sitting in the sun, the tank is only "warm."