R1100S surging

[moa84843]

My 2001 R1100S ran fine for the first 39,000 miles but just started surging - really noticable between 2000-4500 RPM. Has always been dealer serviced. Plugs look good but now a bit black from riding in town. Any idea of the leading cause(s) of surging on the R1100S? I know of the infamous computer fuel mapping problem, but computers usually don't change and this just started happening.

 

[bikerfish1100]

actually a bit rare for R11S models to surge. typically, it indicates need for a valve and TB adjustment. DIY.
there's also a recent thread on this on pelicanparts.com

 

[pglaves]

My 2001 R1100S ran fine for the first 39,000 miles but just started surging - really noticable between 2000-4500 RPM. Has always been dealer serviced. Plugs look good but now a bit black from riding in town. Any idea of the leading cause(s) of surging on the R1100S? I know of the infamous computer fuel mapping problem, but computers usually don't change and this just started happening.

The typical Oilhead surge is a lean surge. So, it is probable that a good running R1100S that begins to surge has developed a lean mixture for some reason. Since it is at low fuel flow conditions it probably is not a fuel pump or filter issue. But it could easily be a slightly/partially clogged injector. That is where I would start.

TB synch is also a good possibility because if unsynched one side will be leaner than the other, and when the O2 sensor and Motronic average things out, that cylinder will be too lean for good clean combustion. Ditto valves.

So - adjust valves, synch throttle bodies. If it still surges, use a good dose of Chevron Techron Fuel System Cleaner in a tank of fuel.

 

[LWS500]

Help R1100r

Need help on R1100R 1999 with 23k
Problem Just started today, right cylinder does not fire untill it wants to.
I switched plugs and injectors from side to side and problem stays on the right side,
Larry:

 

[bikerfish1100]

something that might work for you to reduce a lean condition would be to remove the BBS (big brass screw) from each TB and give them a good thorough cleaning. made a real difference in mine (at around 45K miles) at improving ability of bike to hold a TBS- might also impact lean running condition.
before..

after..

 

[ANDYVH]

My 94 R1100RS has nearly 120,000 miles on it. Twice per riding season I run Techron fuel system cleaner through the fuel system. I also run Autolite 3923 plugs. I have never had the characteristic surging problem and my bike is an early 94 model, which was more likely to have the surging problem, plus it has the older throttle cable setup.

Also, on my bike I installed the GS intake tubes for better mid-range. I realize you can't do that on an S model. But I think the increased air flow velocity may assist some as well.

I really feel a bottle of Techron every year in the fuel system does a lot to avoid fuel injector problems. My bike sits for about four months a year unridden during the Wisconsin winter, and I have never had any fuel related problems. In fact, I just changed the fuel filter at 116,000 miles.

 

[queretaro]

I want to try the Autolite 3923 in my '95 R1100R but can only find resistor plugs. Does it matter if the Autolite 3923 are resistor plugs?
Mark

 

[ANDYVH]

Aside from creating radio noise if you don't use the resistor style plugs, not using resistor plugs can create some running problems. All ignition systems rely on a certain range of resistence to fire properly and with the right spark "dwell". So I'd opt for the resistor plugs.

I'm running the Autolite Platinum 3924 plugs in my 94 R1100RS (121,000 miles) and I have such VERY slight, nearly imperceptible surging that I consider it a non- issue. I just rebalanced my throttle bodies with a manometer (mercury vacuum tubes) which also accounts for the lack of surging. Throttle body air balance is critical.

If, if you do remove the BBS (Big Brass Screws) to clean them it is critical you get them back to the orignal factory setting (assuming the bike has stock intake and exhaust systems). Align a reference dot on the throttle body to the BBS slot with a Sharpie. Then gently turn the BBS clockwise until it lightly seats, and count the number of turns to "seat" it. Record that. Then remove the BBS, clean it, clean the port (carb cleaner works for this). Then apply a drop of light oil to the o-ring, and re-install the BBS until it lightly seats. Now, turn it back to that original position you recorded.

That "may" help reduce the surging. I recently cleaned both BBSs on my bike and was surprised how very grimy they were. But also, I have modified my intake manifolds so I had to reset the air-bleed screws to get my idle reset properly (Thanks Paul Glaves for directing me through that). I am doing some basic home "tuning" for better performance, including buidling my own muffler from a rotted out stock one I got out of the dealer's scrap bin (I'm just that "way").

My muffler design is a free-flowing, baffled, reverse flow design using the muffler can as a resonator (like a Flowmaster muffler common for cars and trucks). It won't be "straight through" but will be less restrictive than stock. I am totally "winging it" design wise but am curious as to sound and performance it will produce.

 

[queretaro]

Thanks, Andy.
I'll install the resistor Autolites and report back. Using a manometer, I've adjusted the balance at idle and at 3500 rpm. It still surges a bit in 1st and 2nd at small throttle openings. I hope the 3923's fatter spark will take care of this. The bike is new to me but comes with nearly 40K miles from 2 previous owners. I adjusted the valves, installed new Bosch plugs, changed oil and filter, trans and rear end oil, replaced the fuel filter. Want to try the Autolite plugs before installing a techlusion.
regards,
Mark

 

[kbasa]

actually a bit rare for R11S models to surge. typically, it indicates need for a valve and TB adjustment. DIY.
there's also a recent thread on this on pelicanparts.com

Same here. The only time my S surged was when it needed those.

 

[Troutluck]

The Autolites made a definite difference on my 'R. More linear throttle response, too.

 

[BUBBAZANETTI]

The Autolites made a definite difference on my 'R. More linear throttle response, too.

i'll third or fourth that, my milage went from 125 to 140 miles till low fuel warning light after switching to these a few months back. never had a surge, but the mileage improvement alone is worth the decrease in cost

 

[Rinty]

surging

How long do those Autolites last?

Rinty

 

[queretaro]

The copper core 3923 cost $1.50 each yesterday at Advance Auto Parts in Fairfax, VA.
regards,
Mark

 

[WOOLF]

surging

had the same thing on my '99 r1100s at 36000 miles,put new rubber intakes on and it now runs as good as new,has 40000 miles now.

 

[BUBBAZANETTI]

How long do those Autolites last?

Rinty

i'd say every 12K replace them, but they're so cheap you could do it every 6K. i will probably inspect them at 6K and decide, no need filling up the landfills just cause things are cheap to replace!

 

[YELLOW_S]

Hey everyone... Thanks for all the info. We got the bike fixed. I'm not sure what was wrong, since my dad fixed it since I was in Germany, and he wanted to ride it. I'll get back later and tell you what was wrong. (hes not around so I can't ask him)

Kevin

 

[queretaro]

I put the Autolites in today; with the gap set at 0.030". The R1100R seems to start a bit easier, and run somewhat smoother. Can't really tell if the improvement is in my head, or in the engine; but it cost only $3.00 and took just 10 minutes so I'm happy - for now.
regards,
Mark