Engine surging

[michaelm]

Hi! I am new to the forum. Bought an '02 R1150RS recently and love everything about the bike except the "surging." When riding at constant speed/rpm it becomes very uneven, surges. It was just tuned before I bought it, TPS, balancing, etc. Runs great on acceleration and deceleration and is not as noticeable at highway speed in higher gears. Dealer says they all do it, just live with it. Can anyone here tell me if this is really that common and if so are there any definitive fixes for it? Can't believe nobody has figured this out as many of these bikes as there are out there. Thanks

[Bob Palin]

What rpm are you running when it is surging? If you are under 4000 then just change down a gear, these machines like to rev. Above that surging can usually be removed by careful throttle balancing, it's very easy to do and with a Twinmax or similar you can do it much better than the shop can with their expensive machine (assuming the valves are adjusted correctly and that's easy too).

 

If after that you still have a surging issue you need to check for leaks anywhere in the air supply system, my bike surged horribly when it had a bad bearing in one throttle body that let air leak in or out.

 

If all that is OK then you have a BMW that surges, some do that! You could get a dual plug kit from San Jose BMW, that stopped mine from surging from 3000 rpm up though it never surged over 4000rpm.

[michaelm]

Bob, thanks for the suggestions. I am planning to check the valves, they were just done by the dealing not long ago but thought I would check myself. The throttle bodies were balanced by the same dealer about 750 miles ago. I'll try double checking that and the TPS as well. What about the timing? Does it help to advance it a bit? Do you know the cost on the twin spark plug conversion form San Jose? Thanks

[TKNorCal]

Check out the Teclusion R-259. Cheaper (much) than dual spark and works.

 

 

 

Link to Techlusion

[John in VA]

Ditto on the Techlusion. It'll make a huge difference in drivability. I should have bought mine the day after I bought my RT.

[Pierce]

I recently pulled the cat code plug(CCP) from my 03, and no more surging. And it still runs great! Pierce

[DEF]

Hi! I am new to the forum. Bought an '02 R1150RS recently and love everything about the bike except the "surging." When riding at constant speed/rpm it becomes very uneven, surges. It was just tuned before I bought it, TPS, balancing, etc. Runs great on acceleration and deceleration and is not as noticeable at highway speed in higher gears. Dealer says they all do it, just live with it. Can anyone here tell me if this is really that common and if so are there any definitive fixes for it? Can't believe nobody has figured this out as many of these bikes as there are out there. Thanks

 

A careful valve lash adjust will do more to reduce surging than TB sync (unless they are WAY out of sync). Also, I have changed to Autolite plugs which helped, as well.

[50Joe]

I bought an '02 1150RT back in September. It surged just like you described. In fact, it had a Techlusion installed, but it was installed wrong. Once I corrected the install, no more surging. Also, I get the same exact mileage as my buddies '05 R1150RT. This was compared over a 1,000 mile weekend trip up in the WV mountains.

[Paul R]

Try doing a search on surging and techlusion. After careful tuning, valve adjustment, and throttle body synch, my 2002 1150RT still surged. I added a techlusion R-259, calibrated it, and no more surge. It made the bike much more enjoyable to ride.

[Peter_Doege]

I had the same issue with my R1100R.

 

I changed the plugs and did a careful TB sync. That cured the problem.

 

I just did a careful valve adjustment and the bike is running great.

 

I don't think that dealers/mechanics have the time necessary to really dial in a bike. I spent about an hour getting mine just right. Much better than what the BMW mechanic did.

 

I would verify the state of tune with a TwinMax and change the plugs to Autolites myself before performing a twin plug conversion or buying a Techlusion.

 

My .02

 

Best of luck,

Peter Doege

[redryder]

Last June I bought an 02 RT from a friend of mine. It was very well maintained and already had a Techlusion installed...in addition to many other farkle and goodies. But, it did surge especially in 3rd and 4th gear near 3500 rpm. The Techlusion helped quite a bit, but didn't eliminate it, but it did drop my mpg down about 5 mpg.

 

I took it to the dealer for its 30K service and the surging did decrease, but only a very slight amount; but at the expense of easy starting when cold. So for the 36K, I did the service myself with LOTS of help from the good people here at this forum. I started with a good valve adjustment, new plugs and then a good, VERY meticulous TB synch. I have literally eliminated all surging and was able to disconnect the Techlusion entirely. The secret is the "meticulous" TB synch. Check on this forum's archives and print out the info. From personal experience though, 1100s and 1150s are NOT the same and it makes for a very long weekend if you mix them up. Armed with the correct information, a good manometer or TwinMax (my choice) and a bag full of patience, you will have your bike running great. I don't buy into the hype that "they all do that". I just don't believe that the dealer's service department will take the time it takes to get your TBs right where they need to be. They get close, but that only counts in horseshoes and handgrenades.

[tom collins]

you didn't mention your milage on the bike. generally, they start to settle down on their own as they approach and pass 20,000 miles. just fyi, the other ideas are all good too. work with it and in the end you will figure out the fix. good luck.

 

tom collins

[Ken H.]

Michaelm,

 

If you want the TB sync procedure Greg is referring to, PM me.

[michaelm]

Thanks for the suggestions. What it is the Autolite plug number you use? Mine has the NGKs in it now. And on the valve adjustment, better to be on the loose side or just spot on?

michaelm

michaelwendymh@zianet.com

[Bob Palin]

And on the valve adjustment, better to be on the loose side or just spot on?

It's not so much that they need to be spot on as that all the valves are the same, the two cylinders must match. I like to keep mine just marginally on the looser side, only to the extent that the guage slides more easily rather than less easily. Valves seem to tighten rather than loosen between checks though mine have stopped changing now.

[russell_bynum]

What Bob said. The key is that all the valves are the same.

[SWB]

Hi! I am new to the forum. Bought an '02 R1150RS recently and love everything about the bike except the "surging." When riding at constant speed/rpm it becomes very uneven, surges. It was just tuned before I bought it, TPS, balancing, etc. Runs great on acceleration and deceleration and is not as noticeable at highway speed in higher gears. Dealer says they all do it, just live with it. Can anyone here tell me if this is really that common and if so are there any definitive fixes for it? Can't believe nobody has figured this out as many of these bikes as there are out there. Thanks

 

I lean towards the view that the problem likely has a undiagnosed, mechanical cause, and that there are multiple potential causes for the same problem. Just about everyone who has it swears by the Teclusion solution, but again, my gut feeling is that it's just covering up another problem. How many BMW's come from the factory with surging as "standard equipment"? Maybe a few, but not the majority of bikes.

 

With my own bike (R1100RTP with 50K miles at purchase), it ran reasonably well when I bought it, but went down hill shortly after. I had both idling and surging problems. I replaced bad plug wires and the coil to boot, added the Autolite plugs, and resync'd the twin throttles, and surging ended and the bike roared with new power. The idling problem is still with me, but I have a couple of ideas about solving that (though others say TADT).

 

On a bike with a few miles and years on it, there are many things that can impact the bikes tuning, including vacume leaks, plugs, wires, throttle sync, and valve lash. I'd go back to basics, and check your bike "from stem to stern", before I'd add the Teclusion, but that's just me. I like things "right".

[John in VA]

My '00RT surged at 3-4k. I did a Twinmax TB sync, valve adjust, new throttle cables, GS tubes, etc., which combined to help somwhat. The idle was stumbly when cold or hot but switching from new Bosch plugs to new Autolites noticably helped that, but I was resigned that it simply wasn't possible for an oilhead to idle perfectly.

 

With all other factors set dead on, I installed a Techlusion and the surging instantly disappeared. Superb drivability and throttle touch made it a whole different bike. What's more, I can start the bike dead cold at 20F by pushing the starter button without touching the throttle and instantly achieve a perfect steady idle that I didn't think was possible. Downside is a loss of 3-5 mpg, but a Techlusion-like brain is exactly what BMW should have built into the bike from the factory.

[Rt4Me]

Techlusion might be your answer. I've had mine installed for years with great results and I'm now running with Autolite plugs. Smooth runnin bike.

[DaveyMac]

For the 1100 RT the correct Autolite is #3923

DaveyMac

[Ken H.]

Just about everyone who has it swears by the Teclusion solution, but again, my gut feeling is that it's just covering up another problem.

Exactly. All the Teclusion does is increase the fuel injector pulse width, feeding more fuel in, and ta-da, problem caused by lean fuel mixture and unbalanced cylinders is masked away.

 

And as mentioned, fuel mileage (and emissions) then goes to pot.

 

For some bikes in the end it may be the only answer. But IMHO it should be a method of last resort. Not the very first thing someone with a poorly tuned surging bike should rush out and buy.

[michaelm]

Thanks for all the input on the surging issue. I got some Autolite plugs and am going to check valves and TB sync this weekend. The bike only has 18k on it, I'm confident that it can run better than it does now. I'll let you know where I end up. Great forum, really appreciate the suggestions.

[A-Red Bill]

I was able to track down and resolve the surging on my bike after fighting it for 40,000 miles or so. I did not use the techlusion or pull the CCP plug.

 

I did careful valve adjusts, TB syncs and all that but with mixed results. Some very good some not.

 

The surge on my bike was caused by an intake leak between the TB and the rubber donut leading to the head. It leaked dispite having the clamp as tight as possible. To resolve the problem I pulled the intake tubes back, removed the TB from the head, oiled the donut, replaced the TB and tightened the clamp before replacing the intake tubes. Note that the intake tubes are dog leged. Get them perfectly aligned with TB before replacing them. Also, oil the o-ring TB. Position the intake tubes and tighten all clamps.

 

My bike has run like a dream since I discovered this technique.

[banta059]

Another ditto on the R259 Techlusion. I to have an 02 RS which i tryed everything on before buying the Techlusion. It just plane works.

Al