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joeangi
Flying Brick Rider
Joined: 03 Apr 2006
Posts: 291
Location: Westchester, New York
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 Posted: Mon Apr 12, 2010 10:59 am Post subject: Throttle body sync |
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I attempted my first throttle body sync and had a few questions:
The brass screws were all like 2 1/2 turns out. As per Drakes instructions, I changed them to 1 1/2 turns. I got them to all sync at idle fairly nicely, bt when you open the throttle they are "out of sync". Is there a preferred RPM range that this should be done? If I remember correctly vacuum is highest at idle, so that should be the most accurate place to match them? Or, should they be matched at 4-5000 rpms? I find just moving the "choke" that they change.
Thanks for any advice. BTW all my vacuum caps were all split, so anything is probably going to be much better.
Joe
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1994 K1100RS
1986 K100RS |
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tmoons
Flying Brick Rider
Joined: 09 Oct 2008
Posts: 161
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| Posted: Mon Apr 12, 2010 2:23 pm Post subject: Re: Throttle body sync |
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| joeangi wrote: | I attempted my first throttle body sync and had a few questions:
The brass screws were all like 2 1/2 turns out. As per Drakes instructions, I changed them to 1 1/2 turns. I got them to all sync at idle fairly nicely, bt when you open the throttle they are "out of sync". Is there a preferred RPM range that this should be done? If I remember correctly vacuum is highest at idle, so that should be the most accurate place to match them? Or, should they be matched at 4-5000 rpms? I find just moving the "choke" that they change.
Thanks for any advice. BTW all my vacuum caps were all split, so anything is probably going to be much better.
Joe |
Hi Joe,
Are you sure the other rubber parts are not in the same state as the vacuumcaps?
If they are also old and worn, you will not get the thing syncho-ed.
specially the ones under the stubs where the injectors go in. |
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SugarHillCTD
Site Admin
Joined: 10 Oct 2007
Posts: 4238
Location: Now in Eastern Pennsylvania
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| Posted: Mon Apr 12, 2010 2:33 pm Post subject: |
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Joe,
I sync them at idle. I think that to even them out above idle requires that you adjust the "forbidden-to-touch" linkage screws- the ones with the yellow paint on them. Many suggest that the Earth's rotation will be affected if you mess with them. 
Seriously- those linkage screws are supposedly set at the factory on a flow bench (if a P.O. didn't mess with them before you got the bike)
Good luck,
John
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John & Cathy
'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F. |
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joeangi
Flying Brick Rider
Joined: 03 Apr 2006
Posts: 291
Location: Westchester, New York
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| Posted: Mon Apr 12, 2010 2:34 pm Post subject: |
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I had checked the rubber parts...The boots looked good. I did find other hoses that were cracked (and replaced). The vac caps still hold, but they are all starting to crack up the sides, so best to replace them.
Joe
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1994 K1100RS
1986 K100RS |
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joeangi
Flying Brick Rider
Joined: 03 Apr 2006
Posts: 291
Location: Westchester, New York
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| Posted: Mon Apr 12, 2010 2:37 pm Post subject: |
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The "do not touch"screws have not been tampered with...thank goodness. I knew it was bad, but I had no idea about altering the rotation. If I had known, maybe we could have had nicer weather sooner this year??
They all sync'd up fine at idle (all approx. 1 1/2 turns out)
Joe
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1994 K1100RS
1986 K100RS |
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RAL88
Flying Brick Rider
Joined: 28 Apr 2004
Posts: 736
Location: New Mexico Land of Enchantment and 365 days of riding USA
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| Posted: Mon Apr 12, 2010 3:22 pm Post subject: |
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| Quote: | | Seriously- those linkage screws are supposedly set at the factory on a flow bench (if a P.O. didn't mess with them before you got the bike) |
Well I can tell you they are not synced on a flow bench. From what I was told by a BMW guy who has been riding for as long as I have been alive the butterflies are set by hand and sighte and then they are set from the brass vacuum screws on the bike. I can concure with this. When I did mine via the never to be touched screws the butterflies were way off. I adjusted the butterflies with my carbtune, set the screws and then synced the throttle bodies with the brass screws. When I did this I lost pretty much all the buzziness and vibration.
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Rich
"If it ain't broke, take it apart and make it work better"
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'96' K1100LT-SE
'97' R850GS-R |
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