ADVrider

Go Back   ADVrider > Bikes > GSpot > GS Boxers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-07-2012, 10:53 PM   #1
Jazz62 OP
Studly Adventurer
 
Jazz62's Avatar
 
Joined: Oct 2009
Location: Midwest
Oddometer: 974
Air bypass screws way off from each other - '00 1150GS

Got Grok's most excellent Harmonizer a few days ago. (can be found here in the Vendors section):

http://advrider.com/forums/showthread.php?t=701625 (no affiliation with Grok etc)

Finally got a chance to play with it today. My new to me '00 1150GS seems to run pretty good but coming from my lumpy and temperamental Multistrada I may be too easy to please. Before hooking up the Harmonizer I checked the position of the big brass air bypass screws. To my surprise the right side was fully seated all the way clockwise, the left side was 2 1/2 turns out from seated. I got the bike warmed up to two bars, turned her off and hooked up the Harmonizer. Started her up and the reading was pretty close to zero, about -18Mbar, BMW spec is +/- 25Mbar. Idle is not rock steady, hovering around 1100-1150. I know there's a lot of things at play here but the valve adjustment was done (by previous owner) less than 500 miles ago, new throttle cables installed around the same time. I turned the bike off and listened to the throttle plates clack closed a few times while twisting the throttle and releasing quickly. I know this is a crude technique but I only heard one simultaneous clack telling me they are at least mechanically in sync. What conditions could exist that would have these air screws set so different from each other. I know this is opening a can of worms but I'm a noob mechanic that needs to learn.

Ron
Chicago

Jazz62 screwed with this post 04-07-2012 at 11:08 PM
Jazz62 is offline   Reply With Quote
Old 04-08-2012, 02:58 AM   #2
PaulRS
Dutch fool
 
Joined: Apr 2008
Location: Holland, land of tulips and wooden shoes
Oddometer: 718
Quote:
Originally Posted by Jazz62 View Post
.............. opening a can of worms..............
Start by taking them Big Brass Screws (BBS) out and clean the tips and holes.
Count the number of turns it takes to bottom, that's your starting point.

Once clean and refitted to that starting point, hook up the harmonizer and check.
With a bit of luck you can get an equal reading by turning one bbs in and the other one out, but they should be within 1/2-1 turn from each other. Less is more here.

If not, set both bbs at 2-1/2 turns out and equalize with the 'forbidden' screw on the rhs cablepully.

Paul.
__________________
Geht net, gibbet net.
PaulRS is offline   Reply With Quote
Old 04-08-2012, 05:05 AM   #3
ragtoplvr
Beastly Adventurer
 
Joined: Oct 2007
Location: S. W. Mssouri
Oddometer: 5,502
Ron, please list the miles on the bike, here are things that happen with the miles. Cleaning the BBS and throttle body is a good first step. I take the throttle body loose, not off, just loose and clean the BBS, passage and around the throttle plate with spray cleaner. I do not like the cleaner gunk going into the engine. That normally fixes the problems. Use lots of rags, some of the cleaner will stain engine paint. Lots of bad stuff in gas anymore. The throttle bushing and shaft can wear at high miles, the best fix is rebuilding, you probably do not have that problem. If you do, it is not real expensive to fix, no big deal.

An idle that varies about 50 to 100 RPM, with a slight stumble at the lowest RPM at about a 1 or 2 second rate is common and due to the emission control, the O2 sensor only reads a narrow range, so the moronic always varies the mixture from slightly rich to slightly lean so the sensor crosses it's reading range. During the lean excursion there is often a slight stumble. Around 2 temp bars on the RID the system goes into this mode, and I can feel it. As the engine warms more, it tolerates the lean mixture more and the stumble becomes less.

Rod
ragtoplvr is offline   Reply With Quote
Old 04-08-2012, 07:10 AM   #4
Jazz62 OP
Studly Adventurer
 
Jazz62's Avatar
 
Joined: Oct 2009
Location: Midwest
Oddometer: 974
The bike has 65K. Is the forbidden screw truly forbidden? I will back the BBS all the way out and clean it up. I thought about doing that but wasn't sure if it were possible to remove it without completely ruining something.
Jazz62 is offline   Reply With Quote
Old 04-08-2012, 07:26 AM   #5
BeamingBeagle
n00btube
 
BeamingBeagle's Avatar
 
Joined: Oct 2011
Location: Los Angeles
Oddometer: 89
bbs screws way off

I have an '01 and everything you're saying about the way the bike runs sounds fine. BUT the bbs should be closer to each other.

I would also point your attention to the valve adjustment. Make sure gap clearance is as close as you can get it and readjust the TBS's. I'm not an experpert by any means but I've done this procedure 3 times now. The better I've adjusted the valves the closer those screws seem to get.
BeamingBeagle is offline   Reply With Quote
Old 04-08-2012, 09:00 AM   #6
Jazz62 OP
Studly Adventurer
 
Jazz62's Avatar
 
Joined: Oct 2009
Location: Midwest
Oddometer: 974
Big problem with BBS o-ring shredding

Okay, so I removed both BBS and cleaned them very well. The o-rings were in their proper grooves on the BBS when removed. When I attempted to install the BBS it shredded the o-ring completely
I don't understand how this could happen. I was very careful in aligning the BBS when inserting it. What the hell do I do now? Can these o-rings be found at my local Home Depot or auto parts store? Of course I was stupid enough to shred both of them. So when re-installing the BBS is the rubber o-ring supposed to be inserted into the hole first then insert the BBS.

Edit - just looked at Max BMW parts fiche and it does not show that there is an o-ring on the BBS screw - wtf?

Jazz62 screwed with this post 04-08-2012 at 09:21 AM
Jazz62 is offline   Reply With Quote
Old 04-08-2012, 09:31 AM   #7
tagesk
Tuscan rider
 
tagesk's Avatar
 
Joined: Jun 2007
Location: Tuscany, Italy
Oddometer: 3,198
First of all: Some first aid.
Get yourself a Gin Martini, possibly a (very) dry one.

With that in hand, you will be (even more) relieved to hear that it is a standard O-ring.
Bring the screw to any hardware store and they'll find you a new one.
The O-ring attaches to te screw, not into the hole.

Then, some theory (which will sink in without resistance as you have now made yourself a second (dry) Martini).

Those screws are for very fine tuning of the air-flow when the throttle bodies are "closed":
I write "closed" since they don't close completely; a sliver of air is let through.
Or, in other words: Those screws are (only) used to ensure you can get the bike to idle perfectly.
No vibrartions, and at about 1100 RPM.

If you screw them "more or less" to the same depth your bike will run just fine.
Although possibly not at idle.

If you have vibrations below, say, 5000 RPM, you need to look carefully at the wires (and not the screws).

Better now?

[TaSK]
__________________
'02 R1150GS - Adds life
My Riding in Tuscany-thread is here.
Renting out motorbikes in Toscana, Italy
Proud contributor to Wisdom and GSpot FAQ and European Ride Report Index.
IBA: 33616
tagesk is offline   Reply With Quote
Old 04-08-2012, 09:36 AM   #8
tagesk
Tuscan rider
 
tagesk's Avatar
 
Joined: Jun 2007
Location: Tuscany, Italy
Oddometer: 3,198
On the other hand....those screws are the very last thing you check.
You have checked the valves (.15 and .30) and sparks - yes?
Then that there is 1mm slack on the wires on both sides - yes?
And you are convinced that when you close the throttle, you hear both bodies "click" close simultaneous - yes?

After checking that, I always balance the throttles at (about) 2.500 or 3000 RPM.
Then I do the idle with the screws at the very end.

Just checking, you know.

[TaSK]
__________________
'02 R1150GS - Adds life
My Riding in Tuscany-thread is here.
Renting out motorbikes in Toscana, Italy
Proud contributor to Wisdom and GSpot FAQ and European Ride Report Index.
IBA: 33616
tagesk is offline   Reply With Quote
Old 04-08-2012, 10:07 AM   #9
Jazz62 OP
Studly Adventurer
 
Jazz62's Avatar
 
Joined: Oct 2009
Location: Midwest
Oddometer: 974
Tagesk - you are very funny indeed. I have one major problem with your advice, I don't drink. Yes, I know this is somehow some major shortcoming of my personality, especially for a jazz musician. Upon closer inspection of the throttle stops I noticed that the left side "sacred" screw doesn't make contact with anything at fully closed position. In the place where it should make contact with something there is just a round hole. The right side "sacred" screw definitely makes solid contact with this same place. The only difference I can see is that on the right side where the left side there is a round hole, the right side has a solid area. Sorry for the piss poor descriptions. Maybe I should try to post a couple of photos. I am relieved that I can source the o-ring easily. What I don't understand is why did the o-ring shred when trying to re-install the BBS? I was careful with it. Does the o-ring need a little silicone grease applied to it first or did I damage the o-ring by allowing to remain on the BBS while it was soaking in the carb cleaner? Also, this is great information to finally understand that the BBS only affect fine tuning at idle. I did not realize this from all that I've read so far.

Note to self: start drinking

Jazz62 screwed with this post 04-08-2012 at 10:15 AM
Jazz62 is offline   Reply With Quote
Old 04-08-2012, 10:24 AM   #10
tagesk
Tuscan rider
 
tagesk's Avatar
 
Joined: Jun 2007
Location: Tuscany, Italy
Oddometer: 3,198
Thumb

Quote:
Originally Posted by Jazz62 View Post
Upon closer inspection of the throttle stops I noticed that the left side "sacred screw doesn't make contact with anything at fully closed position. In the place where it should make contact with something there is just a round hole.
The screw is fixed and points backward (on both sides).
On the thing that turns when you twist the throttle, there is a "stud" that the should rest on the screw then the cable is not pulled.

Fix that first!

How are you going to obtain a proper jazz-esque vice like Luis Armstrong if you don't smoke too much and drink Dry Martinis?

[TaSK]
__________________
'02 R1150GS - Adds life
My Riding in Tuscany-thread is here.
Renting out motorbikes in Toscana, Italy
Proud contributor to Wisdom and GSpot FAQ and European Ride Report Index.
IBA: 33616

tagesk screwed with this post 04-08-2012 at 10:53 AM
tagesk is offline   Reply With Quote
Old 04-08-2012, 10:44 AM   #11
ragtoplvr
Beastly Adventurer
 
Joined: Oct 2007
Location: S. W. Mssouri
Oddometer: 5,502
No silicone grease, it poisons the O2 sensor. You want a viton oring, any auto parts store should have them. Just a dab of oil on it.

Second, the sacred screw seats on a hardened steel button pressed in the steel stamping for the throttle arm. If you have a round hole, yours fell out and this is the root cause. You should see the button on the other side. The throttle plates should not be resting on the bore of the throttle body, they will scar it up.

This needs fixed. never heard of that happening. I suspect you need a good used or new throttle body now.

Rod
ragtoplvr is offline   Reply With Quote
Old 04-08-2012, 11:29 AM   #12
Jazz62 OP
Studly Adventurer
 
Jazz62's Avatar
 
Joined: Oct 2009
Location: Midwest
Oddometer: 974
Here is a pic of the left side (looking down and towards front of bike), you can see the hole and there is no contact with the screw. The right side was impossible to photograph but there is a solid piece instead of the hole and the screw definitely makes contact with it at fully closed position. Jesus Christ, really a new throttle body???!!! Let's see hmm, $450 for a new throttle body or a one-way ticket to Milan...Tagesk, you better make me something strong to drink!


Throttle pulley by piano62, on Flickr

Jazz62 screwed with this post 04-08-2012 at 11:38 AM
Jazz62 is offline   Reply With Quote
Old 04-08-2012, 11:56 AM   #13
ragtoplvr
Beastly Adventurer
 
Joined: Oct 2007
Location: S. W. Mssouri
Oddometer: 5,502
You can even see the witness marks where the button used to be. I would see about getting a screw the right size, file down the head a bit and put a nut on the backside with liberal locktite. Or see a machinist and have him make you a piece to put in there, that would be much less than $450. When you have the throttle body off for the work, you can evaluate if the bore is badly damaged.

If so then used is your best bet

Now something else to worry about, where did I put my BMW worry beads.

Rod
ragtoplvr is offline   Reply With Quote
Old 04-08-2012, 12:17 PM   #14
Jazz62 OP
Studly Adventurer
 
Jazz62's Avatar
 
Joined: Oct 2009
Location: Midwest
Oddometer: 974
There must be something that can be used in place of whatever is there normally without having to replace the entire throttle body. The piece that should be there is some type of press fit thing, almost like a rivet, right? I feel my creative juices starting to flow which is good to counteract the acid in my stomach. What do you mean when you say the "bore" and how would it be damaged by this stud missing?
Jazz62 is offline   Reply With Quote
Old 04-08-2012, 12:25 PM   #15
tagesk
Tuscan rider
 
tagesk's Avatar
 
Joined: Jun 2007
Location: Tuscany, Italy
Oddometer: 3,198
Quote:
Originally Posted by Jazz62 View Post
There must be something that can be used in place of whatever is there normally without having to replace the entire throttle body.
Find as small bolt and make the head as thick as the "stud" on the other side.
At least I would have tried that first.

Unless you happens to be Miles Davies and 450USD is nothing.

They don't need to be exactly equal - you have the brass screw to compensate for some small difference.

[TaSK]
__________________
'02 R1150GS - Adds life
My Riding in Tuscany-thread is here.
Renting out motorbikes in Toscana, Italy
Proud contributor to Wisdom and GSpot FAQ and European Ride Report Index.
IBA: 33616
tagesk is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 04:58 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014