Rough / Weird Idle after Throttle Cam Replacement

[Bigfish]

I used the Beemer Bits Cam Replacements that went really smoothly.

After reinstalling everything and doing several TPS relearns... I am still getting a weird drop and surge to my throttle.

When I first start the bike it feels a bit rough at idle but stays pretty consistent at 1100 rpm.

After it idles for several minutes, I rev the throttle handle and hold at 3000 rpm and after a couple seconds it drops to 900 rpm then ramps up to 3000 then keeps repeating this weird behavior.

 

My best guess is an air leak somewhere? I plan to get 2 new o'rings for the injectors as those should probably be replaced when pulling out then reinserting. Also thinking about a new o'ring for the TPS that I regret removing. Or even getting a whole new TPS in case it got damaged when we tapped in the roll pins for the new cam.

 

I saw a video on youtube to find an air leak by spraying brake cleaner around the TB area and listening for a rev change or stall but this sounds kinda dangerous.

 

Could it be I accidentally twisted a TB cable when putting the cable back in and it is maybe just a little too tight? I still feel slight play at both sides where cable goes into the TBs.

 

Looking for a systematical procedure from someone who may have dealt with similar issue.

 

I sure do feel good about the Beemer Bit parts that are on there now. Just gotta get a smooth idle again and I'l be in business.

 

Thanks in advance!

[dirtrider]

7 hours ago, Bigfish said:

I used the Beemer Bits Cam Replacements that went really smoothly.

After reinstalling everything and doing several TPS relearns... I am still getting a weird drop and surge to my throttle.

When I first start the bike it feels a bit rough at idle but stays pretty consistent at 1100 rpm.

After it idles for several minutes, I rev the throttle handle and hold at 3000 rpm and after a couple seconds it drops to 900 rpm then ramps up to 3000 then keeps repeating this weird behavior.

 

My best guess is an air leak somewhere? I plan to get 2 new o'rings for the injectors as those should probably be replaced when pulling out then reinserting. Also thinking about a new o'ring for the TPS that I regret removing. Or even getting a whole new TPS in case it got damaged when we tapped in the roll pins for the new cam.

 

I saw a video on youtube to find an air leak by spraying brake cleaner around the TB area and listening for a rev change or stall but this sounds kinda dangerous.

 

Could it be I accidentally twisted a TB cable when putting the cable back in and it is maybe just a little too tight? I still feel slight play at both sides where cable goes into the TBs.

 

Looking for a systematical procedure from someone who may have dealt with similar issue.

 

I sure do feel good about the Beemer Bit parts that are on there now. Just gotta get a smooth idle again and I'l be in business.

 

Thanks in advance!

Morning  Bigfish

 

Did this problem just start after the new cam install or was it there before the new cam install? This info might help us narrow down the cause. 

 

When the problem is happening will it still idle OK with no twist grip input?   

 

To me it doesn't sound like an air leak but it could be from a mismatched air flow side to side so have you put a manometer on the throttle bodies to see if the off-idle balance is close. This is important as it not only shows proper balance but will show if you have an air leak effecting the balance, or have a cable tracking issue. 

 

If the cross-side balance is holding close but you still have that RPM surge then your problem isn't in the air flow, or in air leaks,  or steppers, it is in something else like coils or an injector. 

 

It could also be due to one of your idle steppers acting up. 

 

Or even a stick coil fading in & out. 

 

Start by making sure your throttle cables are fully seated in the TB adjusters, then make sure the throttle cables are fully in the cam tracks (In the past  have seen a cable tracking in part of the cam slot then riding on the cam out of the slot for part of the travel).

 

Then, make sure that the cables are fully seated in the cable splitter box  (I have seen cables partially pulled out of that) 

 

Next, make sure that your R/H cable to the throttle body is properly routed around the air box air intake duct area. 

 

Also, verify that the air boots between the throttle bodies & the cylinder heads  are sealing properly on BOTH ends & all the way around.

 

Did you fully support the throttle body arms while driving the pins in? (basically is there any chance that you bent a throttle shaft or throttle lever during the install?) 

 

 

[Bigfish]

Did this problem just start after the new cam install or was it there before the new cam install? Only Started after new Cam Install

 

When the problem is happening will it still idle OK with no twist grip input?   Yes but noticeably rougher idle than Pre Install

 

To me it doesn't sound like an air leak but it could be from a mismatched air flow side to side so have you put a manometer on the throttle bodies to see if the off-idle balance is close. This is important as it not only shows proper balance but will show if you have an air leak effecting the balance, or have a cable tracking issue. I have a TwinMax and if it is OFF IDLE, Which side do I Adjust to bring into balance? Also, I did pull the Stick Coils and did a Valve Check on the Right side and was about to do a Valve check on Left side then decided to just test the bike... I will reseat both stick coils tonight.

 

If the cross-side balance is holding close but you still have that RPM surge then your problem isn't in the air flow, or in air leaks,  or steppers, it is in something else like coils or an injector. I was wondering if it could be a damaged injector o'ring?

 

It could also be due to one of your idle steppers acting up. 

 

Or even a stick coil fading in & out. 

 

Start by making sure your throttle cables are fully seated in the TB adjusters, then make sure the throttle cables are fully in the cam tracks (In the past  have seen a cable tracking in part of the cam slot then riding on the cam out of the slot for part of the travel). I was 99.9% certain I fully put cable in cam track and the throttle cables snapped and locked into place before I slid the cover back over them. I will recheck this if the Idle balance / rebalance doesn't fix the issue.

 

Then, make sure that the cables are fully seated in the cable splitter box  (I have seen cables partially pulled out of that)  Not sure why this would have changes as I didn't touch that area.

 

Next, make sure that your R/H cable to the throttle body is properly routed around the air box air intake duct area. Not sure why this would have changes as I didn't touch that area. 

 

Also, verify that the air boots between the throttle bodies & the cylinder heads  are sealing properly on BOTH ends & all the way around. I looked at these close and appear to be fully seated.

 

Did you fully support the throttle body arms while driving the pins in? (basically is there any chance that you bent a throttle shaft or throttle lever during the install?) We were on a workbench with a padded top and I was holding the TB with both hands to support but did have the TPS (Left TB) still attached because when I took it off I saw the shaft and figured it was better to have the flatter surface with the TPS left on. It was more of a tapping in than a full on hammer blow. But wondering if the TPS got damaged in that process?

[dirtrider]

Afternoon Bigfish

 

Did this problem just start after the new cam install or was it there before the new cam install? Only Started after new Cam Install--- OK that tells us that it something that was effected during or just after the cam install.

 

When the problem is happening will it still idle OK with no twist grip input?   Yes but noticeably rougher idle than Pre Install--- If it idles but just rougher that sort of points to a possible coil issue.

 

To me it doesn't sound like an air leak but it could be from a mismatched air flow side to side so have you put a manometer on the throttle bodies to see if the off-idle balance is close. This is important as it not only shows proper balance but will show if you have an air leak effecting the balance, or have a cable tracking issue. I have a TwinMax and if it is OFF IDLE, Which side do I Adjust to bring into balance? --- You can adjust either side, personally I adjust the side with the tightest cable if I need to loosen a cable to adjust & adjust the side with the loosest cable if I need to tighten a cable to adjust.  
 

I did pull the Stick Coils and did a Valve Check on the Right side and was about to do a Valve check on Left side then decided to just test the bike... I will reseat both stick coils tonight.---Did you have to make any adjustments? If you had to move a valve adjuster more than a hair then definitely re-check that.

 

If the cross-side balance is holding close but you still have that RPM surge then your problem isn't in the air flow, or in air leaks,  or steppers, it is in something else like coils or an injector. I was wondering if it could be a damaged injector o'ring?--- You could have but that probably isn't your problem.

 

It could also be due to one of your idle steppers acting up. 

 

Or even a stick coil fading in & out. 

 

Start by making sure your throttle cables are fully seated in the TB adjusters, then make sure the throttle cables are fully in the cam tracks (In the past  have seen a cable tracking in part of the cam slot then riding on the cam out of the slot for part of the travel). I was 99.9% certain I fully put cable in cam track and the throttle cables snapped and locked into place before I slid the cover back over them. I will recheck this if the Idle balance / rebalance doesn't fix the issue.

 

Then, make sure that the cables are fully seated in the cable splitter box  (I have seen cables partially pulled out of that)  Not sure why this would have changes as I didn't touch that area.--- Well you sort of did as any tugging on the cables during TB removal can pull on those cables.

 

Next, make sure that your R/H cable to the throttle body is properly routed around the air box air intake duct area. Not sure why this would have changes as I didn't touch that area. --- If you unhooked the cable from the throttle body then it is possible.

 

Also, verify that the air boots between the throttle bodies & the cylinder heads  are sealing properly on BOTH ends & all the way around. I looked at these close and appear to be fully seated.

 

Did you fully support the throttle body arms while driving the pins in? (basically is there any chance that you bent a throttle shaft or throttle lever during the install?) We were on a workbench with a padded top and I was holding the TB with both hands to support but did have the TPS (Left TB) still attached because when I took it off I saw the shaft and figured it was better to have the flatter surface with the TPS left on. It was more of a tapping in than a full on hammer blow. But wondering if the TPS got damaged in that process?--- Possible that you damaged it but no way to really know unless you put a GS-911 on it to verify TPS voltage tracking.

[Bigfish]

THANKS DR. I will these checks this evening after work. I do have a GS911 and am getting no fault codes. Might need your advise on where and how to get that TPS voltage tracking verified. I'd love to eliminate the TPS being messed up.

[Bigfish]

I was able to balance the idle using my Twinmax. It was all the way to the "A" (left) side of the Twinmax between 2-3. Started to sound much smoother and feel like the normal idle from previous.

 

So then I rev it up to 3000 rpm and again it starts acting weird where it drops rpms then raises and back and forth. But at idle it seems normal.

 

I recall when I did the new Cam replacement to the Left side first, the original plastic piece broke off with hardly any effort and I had the entire surface to fit the new piece onto. So I ignored the small piece of old plastic that would need to be drilled out and decided it would cause no issues. But when I did the Right side, I had a neighbor buddy who was letting me borrow his nice Vertical drill press and I drilled out the left side and then the inner piece of original plastic fell out as well. So tonight I removed the Right side TB again and definitely noticed the TB motion was sticking and the TB was fairly warm from all my syncing. What I think was happening was as the TB got warmer that plastic piece I failed to remove was binding. Because as the TB was cooling and as I whittled away the plastic, the operation of the spring mechanism felt less sticky. After I got the entire remnants of old plastic off it moved freely with no feeling of binding or sticking.

 

I did one last test as it got late and it all felt normal again even at rev it stayed steady. I will do my Left side valve and rocker clearance check this weekend then re sync one more time and hopefully she will be purring like a kitten again. Never to worry about a TB cam failing me.

 

Including a pic of the plastic piece I want back in and extracted. What the picture doesn't show is the same size piece of plastic on the other side of this metal piece.

 

[dirtrider]

Quote

I was able to balance the idle using my Twinmax. It was all the way to the "A" (left) side of the Twinmax between 2-3. Started to sound much smoother and feel like the normal idle from previous.

Morning Bigfish

 

I don't understand this statement:  "I was able to balance the idle using my Twinmax",  The idle on your hexhead is computer controlled using the electronic steppers (idle control device) . There is NO way to manually adjust the idle balance without messing with the base idle screws & those should NEVER/EVER  be moved to try to adjust idle balance on a computer controlled stepper system. 

 

Please explain in more detail how you balanced the idle?????

[Bigfish]

Oops, I guess I just misspoke.

i did not touch the preset idle screws.

 

I just did a normal sync and it started running way smoother.

 

thanks for all your support DR.

[Bigfish]

Update - When installing the BeemerBit TB cams a drop of locktite got on the surface of the static part. When the Throttle was at idle, it all worked great and when twisting the throttle the engine would not return to the 1100 rpm but race at 2000-3000.

After carefully inspecting the operation of both TBs, I noticed the Right side was very very smooth in its operation from full open to full stop at the idle set screw. The Left side had a definite stickiness right near the closed at idle stop. I put the smallest flat blade screwdriver on the surface where I felt the it was sticking and a chunk of green locktite flaked off. After that, the action of the cam was very smooth. Put everything back on, performed an Idle Actuator Reset and then an Engine Reset using the GS911 and it is working as expected. Moral of this story is to be very very observant. Hope this nugget of info might help someone else out if they have a miss-behaving throttle at idle. I am super good at getting my TB off the bike. Can do it in about 2 minutes. 1 screw, 2 clamps and 2 plugs.