Zounds, what a difference

[Matt, Kazoo]

Did the GS intake tubes replacement as described by Rob Lentini from the IBMWR.org site (oilhead tech articles). I did not replace the yellow cat code plug with the GS pink plug- yet.

 

What a difference!! Super smooth acceleration through all the gears. No pause in the rate of acc. in the 3500-4000 rpm range. Next to none backfiring. Bike is finally running as I feel it should. I'll run a couple tanks of gas through it and check the mpg. Then maybe I'll try switching the cat code plug.

 

If you haven't done this with your 1100RT/RS give it some serious thought. I bought the GS tubes from BeemerBoneyard for about $35 used. Took me about 20 minutes to replace the tubes afer plastic removal. Then about half hour to balance TBs.

[oldyam]

Hi Matt

 

Did mine about 18 months ago with very similar results, certainly in the midrange.

 

Made a massive difference in driveability to two up riding in that area too, about the best money Ive spent since buying the RT

[Matt, Kazoo]

I still can't get over the improvement. Wish I had known of this when I had my 97 RT.

[Selden]

This was just about the first mod I made to my 99 RT, with similar results -- more power where I need it; I don't care if I lose a few HP above 6500 RPM.

 

I tried the pink cat code plug, which yielded about 10% improvement in gas mileage, but drivability was horrible with a cold engine -- or even with a warm engine, such as after a fuel stop. The problem was so bad that I felt it was dangerous; unpredictable engine response when turning out of a driveway is something you want to avoid. I still keep the pink plug in the fuse box, and may even give it a try on a long road trip next week, but in my experience, the improvement in gas mileage is not worth the loss of drivability.

[Urban Surfer]

Will it make a difference on a 1150RT?

[Boffin]

Will it make a difference on a 1150RT?

 

No, it will not. On the 1100 the GS tubes are longer and narrower than the RT tubes. The mod was so popular that the 1150 RT came with the GS tubes from the factory.

 

Andy

[greengary]

I have a '99 R1100RT. What year GS tubes will fit my bike? I'll check Beemer Boneyard.

[oldyam]

I'm pretty sure that the intaker tubes from any 1100GS will fit the part numbers I used were :-

 

LHS = 13711341405

RHS = 13711341406

 

And if I remember correctly they are different lengths, I also ordered the throttlebody 'O' rings too

 

2 off 13541341797

 

as they can be difficult to refit once removed as they swell whilst in use

 

good luck

[NonComp]

Just be aware of one thing, though. With the GS tubes in place, they will not retract into the airbox (due to their length). When I bought my 1100 I did not know that I had GS tubes. When replacing the clutch I wrestled with the tubes for an hour trying to get them to retract as stated in Haynes and other procedure manuals. Could not figure out what I was doing wrong...

[Matt, Kazoo]

This was just about the first mod I made to my 99 RT, with similar results -- more power where I need it; I don't care if I lose a few HP above 6500 RPM.

 

I tried the pink cat code plug, which yielded about 10% improvement in gas mileage, but drivability was horrible with a cold engine -- or even with a warm engine, such as after a fuel stop. The problem was so bad that I felt it was dangerous; unpredictable engine response when turning out of a driveway is something you want to avoid. I still keep the pink plug in the fuse box, and may even give it a try on a long road trip next week, but in my experience, the improvement in gas mileage is not worth the loss of drivability.

 

What kind of milage are you/did you get with the two plugs?

And not to sharpshoot you, but did you pull the fuse Rob Lentini mentions in his tech paper? Could make a difference in drivability?

 

"If the GS intake manifolds worked so well, how effectively would fuel injection reprogramming optimize the system even more? Having experimented with the Motronic fuel injection on my RS, I knew there were six different "maps" stored in the computer which are activated by different "Cat Code Plugs." So, to complete the GS intake "clothes" makeover, I replaced the RS yellow Cat Code Plug with the GS pink unit. This connects different coding plug terminals and activates the GS map instead of the RS'. The coding plug is located in the electrical box under the seat, one row forward of the fuses. Look in your owner's manual for reference. If you replace (or even temporarily remove) the coding plug, you should pull the 5th fuse from the left of the fuse bay for a few seconds and then reinstall it to reset the injection memory and clear any "faults."

Part number and cost for the GS Cat Code Plug is:

61 36 8 366 625 $5.99"

 

TIA for your input, Selden.

[NonComp]

"Part number and cost for the GS Cat Code Plug is:

61 36 8 366 625 $5.99"

 

You don't actually need the Cat Code plugs to play. The plugs are actually just jumpers that short selected terminals together. I made one out of bits of wire and solderless (male) blade connectors. There is a map on the site somewhere of the various combinations.

 

[scout6]

Sure. I get no credit at all.

[NonComp]

Sure. I get no credit at all.

???

[scout6]

Just giving my buddy crap.

[Matt, Kazoo]

Just giving my buddy crap.

 

Nothing new.

Scout 6, alerted me to the GS intake tube mod.

He's a great friend- and never misses a chance to remind me.

[BeemerChris]

Wow, I'm new to your site having just purchased a 2001 R1100RT last week. Its a cream puff with 23,000 miles and its totally stock. The midrange fluffyness/flat spot has been bothering me and I know I'll have to do SOMETHING about it. If what I read here is correct I can install the GS tubes (with new o rings) and I will no longer have this fueling problem? Can it BE that simple? Am I reading this correctly?

 

I live in Orange County California and will join some of you west coast folks for rides / gatherings etc as soon as I figure my way around on this forum.

 

Thank you,

 

Chris

[BeemerChris]

P.S. already did a valve adjustment and TB sync

[Boffin]

Yes, it is that simple. Just get the tubes from the R1100GS and the flat-spot goes away.

 

BTW, Welcome to the forum

 

Andy

[Matt, Kazoo]

As Boffin said, it's that easy. I also went with the Autolite 3923 spark plug replacing a set of iridium plugs. That makes an improvement as well. However, I did the plug replacement before the tube mod. After the plug replacement I still had the flat spot in the torque curve but the engine ran better. HTH

[Peter Parts]

I also went with the Autolite 3923 spark plug replacing a set of iridium plugs.

 

Iridium are the small, single electrode, very pointy, last-like-forever, plugs. If plugs make any difference, they are the top, even helping surging.

 

Unless you mean the XP3923, I never heard of anybody "upgrading" from iridiums.

 

Can you clarify what you did?

 

Ben

[NonComp]

I 'upgraded' to XP3923 iridiums. I like them better than standard plugs.

[Matt, Kazoo]

I also went with the Autolite 3923 spark plug replacing a set of iridium plugs.

 

Iridium are the small, single electrode, very pointy, last-like-forever, plugs. If plugs make any difference, they are the top, even helping surging.

 

Unless you mean the XP3923, I never heard of anybody "upgrading" from iridiums.

 

Yes, I went from the very pointy iridium plugs to the single electrode Autolite 3923. The Autolites cost about a buck fifty a piece, or there abouts.

 

According to my butt, the excelleration and smoothness of the engine was better. I'd run them in my 97 RT with the same results. The iridiums were in the bike when I bought it in March. I changed this month. I've never had nor do I have a problem with surging.

 

Can you clarify what you did?

 

Ben

[SKYGZR]

That would be the Platinum Plug. XPP is Platinum Cathode and Anode both.

[Selden]

What kind of milage are you/did you get with the two plugs? And not to sharpshoot you, but did you pull the fuse Rob Lentini mentions in his tech paper? Could make a difference in drivability?...

 

TIA for your input, Selden.

Belated reply. I pulled fuse #5 to reset the Motronic each time I swapped cat code plugs.

 

October 27-29: Atlanta to New Castle, DE, via Asheville, up I-81, then (after an unplanned stop in Harrisonburg, VA to replace the rear tire) across Maryland. Speeds generally 70-85 (indicated), with tailwinds most of the way, air temperatures 55-70 degrees, averaging 43.9 mpg with the standard (beige) cat code plug.

 

November 6-7: Delaware to Atlanta, via 301 through DE, MD, VA, then I-95/I-85, same speeds (possibly a little higher), again tailwinds most of the way, temperatures 38-60 degrees, averaging 43 mpg with the pink cat code plug. No particular difference starting, slightly worse drivability, mainly immediately after starting (even with a warm engine), and with an occasional hesitation after backing off the throttle.

 

I consider these two mileage figures to be within the range of measurement error. At least in my experience, the pink plug experiment is not worth the effort (but, a cat code plug makes a GREAT tool for an emergency start, if there is a (probable) starter relay issue).

 

[AndyS]

Wow,...purchased a 2001 R1100RT last week....midrange fluffyness/flat spot...bothering me....I can install the GS tubes (with new o rings) and I will no longer have this fueling problem? Can it BE that simple? Am I reading this correctly?

 

 

 

Chris

 

Hi Chris, Fitting the tubes IS that simple.

Will it resolve your problems...maybe - maybe not.

These bikes often display the symtom you descrine, and may need to be gone through from top to bottom

ie, check ignition timing is spot on, check valve gaps are spot on, throttle body synch, Throttle body zero=zero checks, air filter clean, good spark plugs and good spark under power (no dicky HT leads). Correct CAT code plug. good O2 sensor. Then maybe the addition of the GS tube will yield what you look for. But the GS tubes generally will offer better midrange punch at the cost of top end punch (a good trade off for most of us).

So, finally in short, this is not necessarily the solution to your fluffiness.

 

Andy

[aterry1067]

Hi. I did the GS intake tube to my bike today, and truly an amazing difference. I am impressed. Don't forget to get o-rings when you get the tubes. One of mine fell off in pieces when I removed the old tube. The other was reusable.

There are quite a few tech articles on the procedure, that can be found here or with a simple google search. This is the first time I have even had the plastic off, and the left side took me an hour or two (finding a replacement o-ring). The right side took 30 to 45 minutes, including plastic removal/install.

Hope it helps.

 

[SKYGZR]

So what side did you determine to be the "left" and "right"? Did you install the longer tube (right by part number)on the clutch or throttle side? Left & Right could be confusing. Considering that the Clutch side cylinder is further "forward" towards the nose of the machine, it would seem that the longer tube should go on the clutch side.

 

I'm in the process of doing this, and have the longer tube on the throttle side right now. Wondering if it should be changed to the clutch side?

[OlGeezer]

Will it make a difference on a 1150RT?

 

No, it will not. On the 1100 the GS tubes are longer and narrower than the RT tubes. The mod was so popular that the 1150 RT came with the GS tubes from the factory.

 

Andy

 

My intake tubes are not the same as GS intake tubes.

[kmac]

I think it is a low CCA issue which is a problem more in the winter. Batteries loose some CCAs when they are that cold. So the cranking pulls the amps down and triggers the ABS code. I started putting my bike on a trickle charger every night and i have not had the issue since.

[SKYGZR]

I think it is a low CCA issue which is a problem more in the winter. Batteries loose some CCAs when they are that cold. So the cranking pulls the amps down and triggers the ABS code. I started putting my bike on a trickle charger every night and i have not had the issue since.

 

What does this have to do with my previous Question

[cruisin]

yeppers; it's one of the simplest and cheapest ways to see significant gains in mid-range torque. I installed GS tubes in the '98 about a year after I bought it in '01 and then switched them over to the '00 as soon as I got her home. Also use the Autolite 3923 single electrode plugs -- an instrument technician friend of mine who is extremely anal about performance calls them the "best kept secret in the automotive industry."

[SKYGZR]

yeppers; it's one of the simplest and cheapest ways to see significant gains in mid-range torque. I installed GS tubes in the '98 about a year after I bought it in '01 and then switched them over to the '00 as soon as I got her home. Also use the Autolite 3923 single electrode plugs -- an instrument technician friend of mine who is extremely anal about performance calls them the "best kept secret in the automotive industry."

 

So, per my previous question, what side did you install the longer tube in..Clutch or Throttle??

[cruisin]

Beats the heck out of me; I just kept them on the same sides as they came out of the '98 and into the '00. But if you look closely at the numbers stamped into the tubes; the one ending in "05" should be on the left (clutch) and the one ending in "06" should go on the right (throttle).

 

LeftHS = 13711341405

RightHS = 13711341406