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Old 07-06-2014, 06:11 PM   #1
walkingbear OP
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Joined: Jun 2004
Location: Scottsdale AZ..
Oddometer: 3,341
carb sync

Background... have 450 miles on the rebuilt motor..
Last week re-torque the heads.. fine.. nothing floating in the oil.(good news)

The problem I am having is surging.

Doesn't happen in the higher RPM (over 3k) but if you stop too fast the motor will cut out.

Adjusted the cables, sync is jumping all over the place.

Got to also match the left and right (carbtune) and then hit the throttle the left side goes way down.

Ground out the left side and the stays on ...

Ground out the right side the bike dies

I adjusted the air mixture. (don't have a tach R100GS)
So could it be a bad diaphragm in the left carb?
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Old 07-06-2014, 06:21 PM   #2
SOLO LOBO
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Joined: Mar 2004
Location: Shoreline, WA
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Sound like the left side isn't reacting to throttle. If the butterfly is moving then I would suspect a torn diaphragm or stuck slide.
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Old 07-07-2014, 04:11 AM   #3
100RT
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Take the airtube off and stick your finger in and lift the piston to see if the bike runs better at the "Problem RPM" Torn diaphrams wont allow the piston to rise.

Any idea when the carbs were overhauled?
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Old 07-07-2014, 04:37 AM   #4
ME 109
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Location: Albury Australia
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Quote:
Originally Posted by 100RT View Post
Take the airtube off and stick your finger in and lift the piston to see if the bike runs better at the "Problem RPM"
Wear a welding glove, just in case the 'ker backfires!
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Old 07-07-2014, 04:46 AM   #5
Stan_R80/7
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Oddometer: 1,084
If the valve clearance was not checked and re-adjusted after torquing the heads, it needs to be done before continuing. Good luck!
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Old 07-07-2014, 01:11 PM   #6
pommetje
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With Stan.
Also, does this grounding->dying happen at idle? How well does the left cilinder react on the air mixture screw? If not too good, your idle air channel might be clogged.
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Old 07-07-2014, 07:35 PM   #7
walkingbear OP
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Location: Scottsdale AZ..
Oddometer: 3,341
bing

After spend 20 mins with bing.. we decided to
do a full rebuild since .. I did a rebuild on the motor?
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75 R90S , 77 R100 RS,88 R100GS ,94 R1100RS (Aragorn) 2k 1150GS DMC sidecar,
R nine T
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