rockster idle

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morgan9283
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rockster idle

Post by morgan9283 »

I have an '03 Rockster with ~42,000 miles that I cannot for the life of me get idling above 900. I've read countless posts on syncing and my bike just doesn't behave like others. Full disclosure when I first got the bike (around 25k) I naively messed with the throttle stop screws. After reading a few posts on the subject I synced the bike at the throttle stop screws, then with the BBS and then used the right knurled knob and it ran fine. Since then I follow the standard sync procedure and can usually get it running well.

This time I cannot get it to idle above 900 rpms. I had it sync'ed at a local shop and it ran great through the winter. Early summer I noticed the throttle was tough to turn, traced it to the bowden box and *carefully* lub'ed the wheel in the bowden box with silicon spray only (not the cables!). The cables all move freely so I put it back together and the throttle is now smooth as silk though now it's out of sync. I can get it synced both at idle and at 2500/4000 but the idle remains at 900.

The procedure I'm using: set the BBS at 1.5 turns (I've also read 2 turns, I tried both). Sync at idle, sync at 4000 rpms (I've also read 2500 and tried that). Then turn BBS CCW to set idle. All goes well except turning the BBS doesn't change the idle. I've pulled the BBS and all looks clean inside--might it be dirty and just not be visibly so?

Edit: I meant to add that contrary to some procedures I find I have to sync the idle once I've synced at 2500/4000. This makes logical sense to me as I presume the right throttle may not be at the stop after syncing.

Thanks and apologies if this has been covered elsewhere, I've done a ton of reading on the topic and haven't seen my issue specifically.

-morgan
kirby
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Re: rockster idle

Post by kirby »

morgan9283 wrote:I have an '03 Rockster with ~42,000 miles that I cannot for the life of me get idling above 900. I've read countless posts on syncing and my bike just doesn't behave like others. Full disclosure when I first got the bike (around 25k) I naively messed with the throttle stop screws. After reading a few posts on the subject I synced the bike at the throttle stop screws, then with the BBS and then used the right knurled knob and it ran fine. Since then I follow the standard sync procedure and can usually get it running well.

This time I cannot get it to idle above 900 rpms. I had it sync'ed at a local shop and it ran great through the winter. Early summer I noticed the throttle was tough to turn, traced it to the bowden box and *carefully* lub'ed the wheel in the bowden box with silicon spray only (not the cables!). The cables all move freely so I put it back together and the throttle is now smooth as silk though now it's out of sync. I can get it synced both at idle and at 2500/4000 but the idle remains at 900.

The procedure I'm using: set the BBS at 1.5 turns (I've also read 2 turns, I tried both). Sync at idle, sync at 4000 rpms (I've also read 2500 and tried that). Then turn BBS CCW to set idle. All goes well except turning the BBS doesn't change the idle. I've pulled the BBS and all looks clean inside--might it be dirty and just not be visibly so?

Edit: I meant to add that contrary to some procedures I find I have to sync the idle once I've synced at 2500/4000. This makes logical sense to me as I presume the right throttle may not be at the stop after syncing.

Thanks and apologies if this has been covered elsewhere, I've done a ton of reading on the topic and haven't seen my issue specifically.

-morgan
Since you have changed the stop screws a simple ECU reset probably won't work..so

The procedure for resetting the TPS (left throttle body), is kinda delicate to do it properly. So one way for you to do it and get it into the ball park is to increase the left stop screw a very small amount until you get a rise in rpm then duplicate(turns) the same on the right. Do that till you reach 1050 to 1100 rpm.
I don't know what your using to syn the TBs but the idle just needs to be close. ( I use an electronic vac sensor)

Probably the best?!, way for you to get the TPS reset is take it to a good shop unless your handy with a good digital meter and can follow directions.

I don't have the thread but you might search for "TPS reset", which is what you need to do. Unless someone else chimes in with the procedure written out you might try to google" BMW R1150R TPS reset procedure" . Same engine as the rockster.

Once set LEAVE them alone and don't stress out over balance.
mike Mojave CA
'04 ROCKSTER
morgan9283
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Re: rockster idle

Post by morgan9283 »

I was considering increasing the stop screws, thanks.

I'm using a morgan carb tune (carbtune.com)

I have read up on the TPS reset and my sense was that was only to sort surging which has never been an issue on my bike. I'm reasonably handy with a multi meter.

With regards to leaving the throttle bodies alone after balancing my experience has been my bike needs a sync about the same time it needs the valves checked: it runs rough, doesn't idle well, etc. Once synced it runs great.

thanks,

-morgan
kirby
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Re: rockster idle

Post by kirby »

Throttle screws are about the only way to do it properly. They are set at the factory and should never be moved unless you do a complete TPS procedure afterwards.

In over 200K my rock has only needed a tweak a couple of times as far as syn of TB. I will check it once every year and it has been right on except the times I have rebuilt the throttle shafts or messed with the cables. Not unusual for the engine to "sound" or feel a bit rough when you have been running at cruise, flogging it or its hot when at idle. Normally it will clear up after it cools a bit but it will happen now and then. The only way they will really become un syn is if you actually change something. We are talking about the butterfly, you can't change the ECU.

The surging thing is the darkest mystery of the BMW universe and there seems to be a multitude of opinions as to the fix??( or if it is even real). I personally have never felt any surge even on a 1100 GS. But, you can find an epidemic of surging stories on the net.


Not trying to tell you what to do. Just trying to give you a place to start. You may well be much better than I at these things. If your good with working with a meter and you find the procedure,( its out there), its advisable to calibrate the TPS.(because the stop screws have been moved
and if not right the ECU can get confused.)

Some folks are more persnickety than others, much like the surging capers( and other things).

That's all I have.

Good luck!

curious.

:-)
mike Mojave CA
'04 ROCKSTER
kirby
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Re: rockster idle

Post by kirby »

Found this in my notes that was posted here several years ago. I can't find which wires to tap into on the tps plug so you would have to probe in there and find the correct one then to ground.
The idea is to set the (tps on the left) then duplicate exactly this setting on the right. Then on the stops they are balanced and the ecu will command the proper idle rpm when reset. If you have the proper free play in the cables then at idle they will always be on the stops and balanced.

Then you turn the throttle to move them off the stops (about 3000 rpm and balance with the cable adjuster. If the cables do not stretch (not likely) and the adjuster is not moved then they should stay in balance.

See below, author unknown but good procedure.




"Starting with a hot engine (so it idles after basic primary settings) I closed both butterflies, approached left throttle stop with the adjusting screw until the TPS reading just starts to increment. Zero out the TPS mv by turning it's housing to the first millivolt incremental movement (.06mv), then tighten down the 2 blue painted TPS mounting screws. Turn left throttle stop screw to set the TPS reading to 380mv, counting the stop screw's turns, then locknut it in place. Reset the Motronic. Give right TB stop screw the same number approximate turns but leave locknut loose. Set both BBAS at zero. Attach synch tool then start bike. Adjust only the right throttle stop screw to synch the idle, tighten it's locknut. Idle will be very slow, so use both BBAS to get 1150 RPM. Shut off engine. Set left throttle cable freeplay to <1mm but not zero. Snug it's locknut and check freeplay again. Same for right side but leave it's locknut loose. Check for each exposed throttle wire's minimal sway deflection while throttle does not open on both sides. Start engine and set "on throttle" synch (~3,000RPM) adjusting only the right side cable. Turn steering lock-2-lock confirming there is no RPM increase. Set fast idle lever upper end's freeplay to zero or 1 turn below zero. Turn steering lock-2-lock confirming there is no RPM increase then see how far you can pull up on the fast idle lever before the RPM increases. You can continue half turns of negative cable adjuster freeplay with steering and lever tests -until- the RPM increases after the lever's tip moves ~3/4" before RPM's increase. All those minimum/negative cable freeplay adjustments contribute to the fast idle lever working really well, giving you ~1,600 RPM low idle with a cold engine."
mike Mojave CA
'04 ROCKSTER
morgan9283
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Re: rockster idle

Post by morgan9283 »

Thanks Mike, I appreciate the info/insight. I am going to start with a tweak to the stop screws as everything I read is messing with the TPS is a last resort and to deal with surging. My bike runs very smoothly and is easy to sync, just doesn't idle high enough. I don't want to mess with the TPS until I'm out of options. There's a lot of conflicting info floating around about these stop screws.

-morgan
kirby
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Re: rockster idle

Post by kirby »

Until you set the proper voltage(set by moving the set screw) on the tps the ecu will be confused about idle speed. By tweaking the left one up it will increase the voltage(and idle) but what ever you do to the left you MUST duplicate it on the right or it will never be right.

The electric carburetors on the beemer are pretty dumb and only spray fuel into the TB according to a couple of parameters. Set right they should never need syn at idle, (its mechanical) unless you move those screws. The only adjustment should be off the stops like 3000 rpm with the right cable adjuster.

If that procedure scares you then your probably right not to get into it, but when you turn(ed) that left stop screw you ARE(did) mess with the TPS.

Good luck I really have no more.

mike
mike Mojave CA
'04 ROCKSTER
morgan9283
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Re: rockster idle

Post by morgan9283 »

You make a good point: at least according to zero=zero on the ibmwr (http://www.ibmwr.org/r-tech/oilheads/zero528.shtml) the obvious solution is for me to adjust the left stop screw until the tps shows a voltage of .370-.4, sync with the right stop screw then follow up with standard sync. That is to say I shouldn't touch the TPS since I don't have surging issues. Surely this won't make my situation worse.

Thanks for the advice.

-morgan
kirby
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Re: rockster idle

Post by kirby »

But when you move the stop screw on the TPS(the big black square thing on the left only which is just a rheostat connected to the throttle shaft!) you ARE MESSING with the TPS and changing the voltage.
I posted the proper way to do it. This surging thing is mostly myth.
mike Mojave CA
'04 ROCKSTER
morgan9283
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Re: rockster idle

Post by morgan9283 »

Mike,

Right, I understand. I am perhaps using the wrong terminology. The stop screw(s) I'm referring to are the throttle stop screws--the little screws behind the throttle bodies that the butterflies rest on. I naively used those to set the idle when I first bought the bike. That's all I changed so it makes sense to set the left one back to .370-.4 and then sync the right to it, yes? If that doesn't work I'll do the full zero=zero which is effectively what you posted.

thanks,

-morgan
kirby
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Re: rockster idle

Post by kirby »

I understand which screws your talking about, same as me.
That was the first solution I suggested in the beginning. Set the idle with the left screw and use your balance device to set the other, AT IDLE.(both on their stops) Move the left up a little at a time because as you move the right one you will overshoot your 1050/1100 #. Maybe the left up to 1000 then balance and see where you are.
That should be close enough.
Then use the cable adjuster on the right to balance OFF THE STOPS (usually around 2K to 3K.
mike Mojave CA
'04 ROCKSTER
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Re: rockster idle

Post by two wheel tango »

This thread on advrider is worth a read....

http://advrider.com/index.php?threads/t ... ro.996719/
kirby
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Re: rockster idle

Post by kirby »

two wheel tango wrote:This thread on advrider is worth a read....

http://advrider.com/index.php?threads/t ... ro.996719/

I really don't agree with much of this post in the details. To me its confusing to the unaware. You do use the voltage to set the TPS, its just a rheostat to tell the ecu the throttle position. Dead simple. The electric carburetors are very basic and just spray fuel according to a couple of parameters, and the TPS is not linear past about 1/3 throttle where it jumps to max voltage telling the ecu the throttle is WFO. Mechanical carbs do the same thing w/ tapered needles and jets etc..

It really matters not to me as I do my own thing from 3 oil heads and 350K miles.
Folks can believe what they want. Its not rocket science just needs to be reasonably close.

I would thank the poster for his effort and tell him to chill.
mike Mojave CA
'04 ROCKSTER
morgan9283
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Re: rockster idle

Post by morgan9283 »

Alas I'm at an impasse with this. I'm working on getting an appointment with my local shop. Here's where I am:

I loosened the left idle stop screw and adjusted it to .310, .370 and .4v based on various Internet sources. I then sync'ed the right throttle stop screws, the BBS and with the throttle at 1500-3000 RPMs. In all cases the idle stays at 900 or lower and adjusting the BBS doesn't affect the idle. The bike is otherwise smooth as silk so the sync'ing is presumably working.

I checked my records and realized it was due for a valve check so I did that--the right intake valves were .001in loose but otherwise they were in spec. After adjusting the valves and repeating the above the idle jumped to 1100-1300, it creeps up and down over the course of a short ride. The BBS still don't affect the idle. I think the idle jump is a red herring--the idle on this bike has always moved around over time.

I've pulled the BBS and it looks clean in there, no blockages certainly.

It is also due for spark plugs which I have on the way. I'll be embarrassed if spark plugs fix this.

A few years ago after too many trips back and forth a local shop told me I had a bad left coil and the right coil was weak. They also did valves, TD sync and plugs. They replaced the left coil and bike ran great for a year or so. The idle misbehaved a year later so I replaced the right coil to no effect. I took it to another local shop and they got it idling well with just a TB sync (with the old coil) and told me they've never seen a bad coil. I returned the coil I'd bought. I hesitate to replace the coil this time.

I'll update once I get it to a shop.

Edit: some potentially helpful links:

http://advrider.com/index.php?threads/r ... ero.53667/
Note at the end of page 2 his problem is solved with new coils:
advrider.com/index.php?threads/stumped-by-the-idle-adjustment-r1150gs-2004.618088


thanks,

-morgan
morgan9283
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Re: rockster idle

Post by morgan9283 »

I finally got my bike into Spare Parts Co, our local indie BMW shop: he just said it needed to be properly set up. I've ridden almost 1000 miles and the bike runs perfectly. We briefly discussed what he did and it seems to just boil down to setting the TPS and properly sync'ing. He did say the 1150 in particular has to be just right or it runs terribly. Though he said if I bring it back every 6000 miles it should continue to run well. I clearly have a lot to learn about tuning boxers.

If anyone is within a days ride of Philly and would like to help me with my next sync I'd be happy to supply dinner or a case of your favorite beer.

Thanks for the help everyone.

-morgan
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