Peculiar rough running R1100R

[Pfestus1]

I bought this 1998 R1100R/Hannigan sidecar rig last fall with 54,000 miles. Now has 60,000. In April I rode it to Texas on a 4200 mile trip. This problem began after a fill up in College Station Tx. As I exited the gas station, when I applied throttle it felt like one cylinder was cutting in and out, running very rough as I accelerated. Above 3500 rpm it smoothed out and ran fine till the next time I shut it off, then restarted and took off, it did it again. First thought was bad gas, so I began adding some fuel/injector cleaner and HEET. The problem persisted the rest of the trip, and even to this day. About the same time one of the fuel lines started leaking (I doubt any relation between the two). When I got home I ordered new fuel line, in tank fuel filter, pump and hoses (from EME). I replaced the high pressure lines on the outside of the tank, and installed the new fuel filter and pump. Problem still present. Next I replaced the spark plugs and wires, still no change. Then a new coil, no change. Then a new Hall Effects sensor, still no fix. The old Hall Effects looked bad as the insulation on the wires coming out of the plug was gone. I had high hopes that would fix the problem. Next, this week, I pulled the injectors and cleaned them using a short piece of hose, a plug drilled for a tiny straw, a 9v battery to open the injector, then sprayed carb cleaner thru them.. Still did not fix the problem. 

 

The peculiar thing about this problem is it does not happen when engine is cold, but after I stop, like for gas, and shut off the engine, when I take off again, it idles fine, but as I twist the throttle it bucks and snorts like one side is cutting in and out. More throttle it cuts in, let up it cuts out, then above about 3500 it smooths out and runs right. Stopping for a stop light or such it does not do this, only after engine is hot, and bike is shut off for a few minutes. 

 

Does anyone have any ideas as to what is going on, or has had a similar problem? 

 

Thanks for any help. 

 

Hank Pfister

Roanoke, VA

[dirtrider]

22 minutes ago, Pfestus1 said:

I bought this 1998 R1100R/Hannigan sidecar rig last fall with 54,000 miles. Now has 60,000. In April I rode it to Texas on a 4200 mile trip. This problem began after a fill up in College Station Tx. As I exited the gas station, when I applied throttle it felt like one cylinder was cutting in and out, running very rough as I accelerated. Above 3500 rpm it smoothed out and ran fine till the next time I shut it off, then restarted and took off, it did it again. First thought was bad gas, so I began adding some fuel/injector cleaner and HEET. The problem persisted the rest of the trip, and even to this day. About the same time one of the fuel lines started leaking (I doubt any relation between the two). When I got home I ordered new fuel line, in tank fuel filter, pump and hoses (from EME). I replaced the high pressure lines on the outside of the tank, and installed the new fuel filter and pump. Problem still present. Next I replaced the spark plugs and wires, still no change. Then a new coil, no change. Then a new Hall Effects sensor, still no fix. The old Hall Effects looked bad as the insulation on the wires coming out of the plug was gone. I had high hopes that would fix the problem. Next, this week, I pulled the injectors and cleaned them using a short piece of hose, a plug drilled for a tiny straw, a 9v battery to open the injector, then sprayed carb cleaner thru them.. Still did not fix the problem. 

 

The peculiar thing about this problem is it does not happen when engine is cold, but after I stop, like for gas, and shut off the engine, when I take off again, it idles fine, but as I twist the throttle it bucks and snorts like one side is cutting in and out. More throttle it cuts in, let up it cuts out, then above about 3500 it smooths out and runs right. Stopping for a stop light or such it does not do this, only after engine is hot, and bike is shut off for a few minutes. 

 

Does anyone have any ideas as to what is going on, or has had a similar problem? 

 

Thanks for any help. 

 

Hank Pfister

Roanoke, VA

Evening Hank 

 

Does your motorcycle still have a CCP in the fuse box? If so then try removing that & ride the motorcycle for a few days. That will take the o2 sensor control out of the fueling loop. Look to see if your o2 sensor pigtail wire is hanging down onto the hot exhaust.

 

If your motorcycle still has the OEM emission Evap canister (black can on right rear of the motorcycle) try unplugging the vacuum hoses from the bottom of the throttle bodies then plug the vacuum fitting on the bottom of the throttle bodies.  (this will prevent raw fuel from entering the throttle bodies if you have an Evap canister problem).  Then try riding the motorcycle for a few days.

 

Otherwise you might run a fuel return hose flow test, run a leak-down test (you might have a slightly leaking valve), check your TPS voltage & check the TPS voltage sweep, a TPS (Throttle Position Sensor) acting up can sometimes  cause something like you are feeling).

 

Make sure that your coil & fuel injectors are operating at over 12 volts (low voltage to either can cause runability problems). 

 

I didn't see where you installed a new "U" shaped high pressure hose inside the fuel tank, if that has a small pin hole or a split (not uncommon in older Boxer bikes) that can significantly lower the fuel pressure (a fuel return hose flow test can prove or disprove this). 

 

Look closely at the R/H side throttle body cable cam to R/H side spark plug wire clearance, if the R/H plug wire is out of place the TB cam can wear into it at certain throttle positions.  

 

This should be enough to keep you busy for a while. 

 

 

 

 

[Pfestus1]

D.R., thanks for the great help. I checked the fuse box and there is a pink relay that I assume is the CCP. I pulled out. I went for a ride to town to Advance Auto which is far enough to produce symptoms when I start up and leave. When I left the bike accelerated fine with no hiccups or misses. Made another stop, and same thing when I left for home. I"ll see how it does the next few days. Is it ok to run without that CCP permanently, or should I get a new O2 sensor? Pic of the relay I pulled out.

 

Thanks again, you're a genius! 

[dirtrider]

On 5/23/2023 at 8:26 PM, Pfestus1 said:

D.R., thanks for the great help. I checked the fuse box and there is a pink relay that I assume is the CCP. I pulled out. I went for a ride to town to Advance Auto which is far enough to produce symptoms when I start up and leave. When I left the bike accelerated fine with no hiccups or misses. Made another stop, and same thing when I left for home. I"ll see how it does the next few days. Is it ok to run without that CCP permanently, or should I get a new O2 sensor? Pic of the relay I pulled out.

 

Thanks again, you're a genius! 

Morning  Hank 

 

A large number of us BMW 1100 riders ran the 1100  motorcycle without a CCP for it's entire life.  The BMW 1100 Ma 2.2 has a decent open loop fueling map so they run pretty good (actually better than closed loop on the o2 sensor) 

 

About the only things you should notice is some or most of the light throttle surging is gone with the CCP removed  & most likely you will have a higher engine idle speed. 

 

If the hot engine curb idle is too high then turn each side throttle body BBS (Big Brass Screw) in equal amounts (1/4 turn, 1/2 turn. 3/4 turn, etc  until it is back where it was. 

 

You might notice a slight drop in fuel milage (some riders did) but personally I never noticed much difference. 

 

 

[Joe Coastie]

I can't help you with your problem. Just wanted to compliment you on your rig, very nice.

[jacksdad63]

On 5/24/2023 at 11:50 AM, Joe Coastie said:

I can't help you with your problem. Just wanted to compliment you on your rig, very nice.

Me too! Never been a sidecar fan, but this one looks pretty cool, lets hope the experts on here get things sorted...I'm positive they will 

[Pfestus1]

Follow up: So, without the O2 sensor my bike ran great. I ran it like that to the MOA Rally north of Richmond and the bike ran fine the whole way. My fuel economy did suffer, dropped into the high 20s with a good load in the sidecar. Once home I ordered an O2 sensor from EME. Now that is in and all is well, my fuel economy back up the mid 30s. 

 

The trunk on my R1100 holds a 2 gal reserve gas tank, with a transfer pump. This week we are replacing the 2 gal tank with a 4 gal tank. Hopefully that will give my about 240 mile range. 

 

Thanks for the help, especially you, Oracle.