Sticking throttle on running GS

[Still CAL]

Hello all. This is on a 2005 R1200GS with 41k miles. The throttle only sticks while I'm riding. Sitting in the shop, the throttle is smooth and always returns to the idle stops instantly. I haven't used the grip heaters yet, plus it was near 100º on the ride today. But it does the same thing when the temps are in the 50s.

 

Occasionally it sticks for several seconds, but usually it's just enough to tell that it's hanging up. I know Chris Harris talks about worn TB butterflies causing issues, does it seem like that could be my problem? I'll probably remove the TBs tomorrow to see if I can find out anything. I just hope it's not the pulleys cracked and coming apart.

 

Thanks for your help.

[dirtrider]

9 hours ago, Still CAL said:

Hello all. This is on a 2005 R1200GS with 41k miles. The throttle only sticks while I'm riding. Sitting in the shop, the throttle is smooth and always returns to the idle stops instantly. I haven't used the grip heaters yet, plus it was near 100º on the ride today. But it does the same thing when the temps are in the 50s.

 

Occasionally it sticks for several seconds, but usually it's just enough to tell that it's hanging up. I know Chris Harris talks about worn TB butterflies causing issues, does it seem like that could be my problem? I'll probably remove the TBs tomorrow to see if I can find out anything. I just hope it's not the pulleys cracked and coming apart.

 

Thanks for your help.

Morning  Still CAL

 

The throttle plate shafts spin on actual bearings in the 1200 hexheads so the throttle plate area is usually not an issue on the 1200GS. 

 

Do check for cracked cams, then make sure the throttle cam covers are not interfering with throttle action.

 

Sitting in your shop see if you can make them stick with the handlebars turned to either side. 

 

Also,  try to get the throttle to stick with the engine (riding hot) right after returning from a ride. 

 

Make sure the throttle cables are adjusted correctly with enough slack as the cables do change length slightly from cold hot. 

 

I have also seen the hexhead throttle cables get sticky feeling (not actually stick though) if they are lubricated with old style cable lube as that stuff can swell up the cable inner liners.    

 

You might also remove the throttle cable splitter box cover then flush the insides out with WD-40 & light compressed air. 

 

You might also remove the twist grip then clean the tube inside & the bar area that it rotates on. 

 

To repair the sticking you first need to find out where in the throttle system it is sticking. 

 

Are you SURE that it is actually a sticking throttle & not a vacuum leak or a stepper not following computer commanded counts????   

[Still CAL]

Dirtrider,

The throttle tube physically remains in place until such time as vibration or a bump or just at random it snaps to idle, and the engine returns to idle with it.

 

I stopped after 70 miles of riding to air the tires back up for the last 20 miles of mostly pavement. I tried the throttle at that time with the engine off and felt no discernible sticking. I don't lube the cables, but the bike is new to me as of last summer so cable condition is unknown.

 

I performed a TB sync last fall; the cable freeplay was good then. I'll go through your suggestions today and see if I can find anything. 

Happy Father's Day.

[Still CAL]

So there's this:

 

Right throttle body, so good thing I went looking. There was roughness in the throttle but no actual binding; but under operating conditions and temps that could change. This was a Florida bike in its PO life, so still digging sand out of it. When I get the cable box apart I'm sure I'll find more grit.

 

Throttle cables look to be original so I'll just overhaul the whole system. As far as the cracked pulley goes, I'll attempt the JB Weld repair as done here: https://advrider.com/f/threads/2009-r1200gs-throttle-does-not-return.1503214/

[dirtrider]

25 minutes ago, Still CAL said:

So there's this:

 

 

Right throttle body, so good thing I went looking. There was roughness in the throttle but no actual binding; but under operating conditions and temps that could change. This was a Florida bike in its PO life, so still digging sand out of it. When I get the cable box apart I'm sure I'll find more grit.

 

Throttle cables look to be original so I'll just overhaul the whole system. As far as the cracked pulley goes, I'll attempt the JB Weld repair as done here: https://advrider.com/f/threads/2009-r1200gs-throttle-does-not-return.1503214/

Afternoon Still CAL

 

That will probably eventually get you a walk home, hopefully from not too far of a remote area. 

 

You can buy new cams with shafts from Bing USA. I did write up on installing the new cams & shafts that has been working out pretty darn good on the ones that I & others have done.    

[Still CAL]

1 hour ago, dirtrider said:

Afternoon Still CAL

 

I did write up on installing the new cams & shafts that has been working out pretty darn good on the ones that I & others have done.    

Linky? I'd prefer to go with Bing. Neither pulley is cracked all the way through, and finishing them off may make it hard to reassemble them with any confidence. Breaking down with only a Garmin satellite link for coms won't be too much fun.

 

Looks like Max BMW for the cables, didn't find any cheaper. Sand everywhere. Also found this on the throttle tube.

 

The manual doesn't indicate any lube in here, but there's gunk on the tube and bar end. Almost looks like Staburags. I'll get it good and clean before reinstallation. I'm guessing the white on the bar is a factory coating for slickness.

 

Meanwhile, I guess I'm stuck riding the '08 RT.

[dirtrider]

Evening Still Cal

 

That twist grip tube is probably your sticking throttle.  Do not use anything gooey or oily to lube that area. Personally I use a Tri-Flow (the old original formula) as that evaporates & leaves a dry Teflon coating.

 

Here are the Bing cam/shafts__

 

http://bingcarburetor.com/store/p134/Type_77_Throttle_Body_Pulley_%26_Shaft_Assembly.html

 

Here is write-up for a workable TB cam/shaft replacement__ It is the preliminary, I have defined it a little since the write up but it is pretty close to this.  

 

 https://www.bmwsporttouring.com/topic/91991-throttel-body-throttle-shaftcam-install-procedure_/?tab=comments#comment-1021593

 

[Still CAL]

3 hours ago, dirtrider said:

Evening Still Cal

 

 Personally I use a Tri-Flow (the old original formula) as that evaporates & leaves a dry Teflon coating.

 

 

 

Thank you. Tri-Flow has several products, got a link or pic of what you use(if they still make it)? Cheer-o.

 

[dirtrider]

12 hours ago, Still CAL said:

Thank you. Tri-Flow has several products, got a link or pic of what you use(if they still make it)? Cheer-o.

 

Morning  Still CAL

 

A picture won't help as my Tri-Flow is not in it's original container (I have it in a bottle with a long thin needle for precise placement)

 

In any case the Tri-Flow I have is the old version that they don't make any longer.  

 

I'll see if I can find the current Tri-Flow that is close to what I have __

 

Added: This is as close as I  can find in their current offerings.   

[Still CAL]

Thanks for the pic, dirtrider. I was looking for sprays so didn't think about a liquid. I'll check it out.

 

Parts are on the way from Bing. Meanwhile, I've prepped the right TB with marker and scribe lines on the brass plate. Something was mentioned in the replacement thread about stepper counts and cross balance; I'm guessing that was done prior to removal with a GS-911? I have one but it's still in the wrapper, as I thought I would only need it to read fault codes. Noobeemer nerd, right?

 

I'm not having great luck measuring gaps with my feeler gauges. On both TBs, with a 0.002" leaf at 12 o'clock, the 0.0015" leaf will not go through the idle stop; at 6 o'clock however, it will. With a 0.0025" leaf top or bottom, the 0.002 leaf goes through the idle stop with slight drag. I'll do this repeatedly to get consist results before I take anything apart, though. And make sure the TB bore and plate are super-clean and free of any grit, dirt, spooge, etc. that could interfere with my measurements.

 

Can't see the scribe lines but they're there:

[Still CAL]

Side question: since I'm there, what are people's thoughts on doing the ABS mod to get rid of the whizzy brakes? Doesn't look terribly hard. They work fine now, and I flushed and refilled the module last fall.

[dirtrider]

1 hour ago, Still CAL said:

Side question: since I'm there, what are people's thoughts on doing the ABS mod to get rid of the whizzy brakes? Doesn't look terribly hard. They work fine now, and I flushed and refilled the module last fall.

 

Afternoon  Still CAL

 

Unfortunately on the hexhead motorcycles it isn't as straight forward as on the earlier 1100/1150 bikes.

 

Due to the onboard electronics, ABS module brake light control,  & speedometer problem you pretty well have to keep the black box operational from the ABS module. That isn't that difficult if you build a nice waterproof cover for the black box.

 

BUT, you still have that darn dash warning light to deal with, unlike earlier BMW motorcycles that dash light bulb(s)  are not  removable so even if you tear the dash apart & cut the trace going to the bulbs then you then lose your dash general warning light that warns of other malfunctions. 

 

It IS doable, just not easy & straight forward without additional baggage. 

 

There is a company (I believe in Germany)  that sells a bolt-in ABS removal electronics spoofer but it is very expensive. I no experience with doing it that way.  

[Still CAL]

Thanks DR, it stays the way it is for now. Onward to the TB shafts.

[Still CAL]

Parts came in Friday. I've temp installed the right throttle plate, but I only have one set of feeler gauges that go down to 0.0015". Went to the village hardware store but they didn't have one, so beat feet home on the RT as it started to rain. I'll go to the city tomorrow and get one at O'Reillys since I have to go to the post office anyway. 

 

I'm also waiting on a new main accelerator cable from MBMW; it was a little draggy, but the short ones feel fine so didn't pop the 74 bucks per for them. The o-rings are broken or missing on all three cables where they go into the Bowden box. Probably okay to just use sealer on them?

 

Good Sunday.

[dirtrider]

14 minutes ago, Still CAL said:

Parts came in Friday. I've temp installed the right throttle plate, but I only have one set of feeler gauges that go down to 0.0015". Went to the village hardware store but they didn't have one, so beat feet home on the RT as it started to rain. I'll go to the city tomorrow and get one at O'Reillys since I have to go to the post office anyway. 

 

I'm also waiting on a new main accelerator cable from MBMW; it was a little draggy, but the short ones feel fine so didn't pop the 74 bucks per for them. The o-rings are broken or missing on all three cables where they go into the Bowden box. Probably okay to just use sealer on them?

 

Good Sunday.

Afternoon Still CAL

 

Yes you can probably use a little sealer on the cable ends that go into the splitter box. The R/H side tends to pull out slightly during air filter changes so maybe the sealer will help it stay in place. 

 

Make sure the your throttle shafts are properly centered in the throttle bore so air can't get by around the ends of the throttle plate notch. 

[Still CAL]

I suppose Bing has robotic machines to get everything lined up correctly, then flow benches to set them up. Or maybe just install the throttle plate without the stop screw with no gaps around the edges, then set up the stop screw. Think that might be another way to approach this?

[dirtrider]

6 minutes ago, Still CAL said:

 Or maybe just install the throttle plate without the stop screw with no gaps around the edges, then set up the stop screw. Think that might be another way to approach this?

Evening   Still CAL

 

I have done a couple this way (still using the scribed lines to get the throttle plate  clocking back to where it was).

 

It works but doesn't seem to give me as good of results as using the feeler gauge method. 

[Still CAL]

Success! New throttle plates installed and everything back together. TwinMax shows the sync almost dead on. It took a few minutes for the ECU to iron things out, but once it did I could swear the throttle response is quicker than before. Snapped my head back a couple times.

 

Dirtrider's procedure worked to a tee, I have nothing to add to it. I don't know what the stepper counts are that were referred to by another poster. I may have more to do as I was only able to ride two miles because of the weather here. When it clears I'll go for a longer cruise to make sure everything is good.

 

While I had it apart I replaced the long throttle cable and cleaned all the Florida sand from everything I could get to. I also installed a Powerlet port on the left upper fairing so I'll have good power when I need it. And the top case got a new from BMW bottom; the old one broke at the latch point and dumped the case in the road twice. Looks like that happened to the PO also if the gouges on the lid are any indication.

 

Thanks to dirtrider for all your assistance on this project.

 

And now:

 

We ride!!

[dirtrider]

On 7/1/2021 at 6:29 PM, Still CAL said:

Success! New throttle plates installed and everything back together. TwinMax shows the sync almost dead on. It took a few minutes for the ECU to iron things out, but once it did I could swear the throttle response is quicker than before. Snapped my head back a couple times.

 

Dirtrider's procedure worked to a tee, I have nothing to add to it. I don't know what the stepper counts are that were referred to by another poster. I may have more to do as I was only able to ride two miles because of the weather here. When it clears I'll go for a longer cruise to make sure everything is good.

 

While I had it apart I replaced the long throttle cable and cleaned all the Florida sand from everything I could get to. I also installed a Powerlet port on the left upper fairing so I'll have good power when I need it. And the top case got a new from BMW bottom; the old one broke at the latch point and dumped the case in the road twice. Looks like that happened to the PO also if the gouges on the lid are any indication.

 

Thanks to dirtrider for all your assistance on this project.

 

And now:

 

We ride!!

Morning  Still CAL

 

Sorry for taking do long to get back to you,  I was on the road plus with the site upgrade I just forgot to reply. 

 

It sounds like you have it back to where it belongs, I do like hearing back on these as it helps me understand the procedure in more detail. 

 

If you think of it please post a follow-up back here after a couple of thousand miles of riding on how it ultimately settles out?  

[Still CAL]

Will do. I was going to start this thread in Hexheads so more people would see it, but since it's a GS...

 

It's monsoon season here in the Sacramento Mountains of New Mexico, so mostly gazing out the window waiting for drier weather to get a long test ride.

[Still CAL]

Update: Did a 120-mile ride through the mountains and high desert. Bike is running great, and the sticking throttle is also gone. The only thing off was the free play, which adjusted out with a few turns of the adjuster at the throttle.Thanks again to dirtrider and the others who have gone before for posting up a great, easy-to-follow procedure on replacing the TB  throttle plates/butterflies.