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jchen
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Joined: 07/07/2015
Posts: 17

I hadn't ridden my girl in 10days and everything was fine before, but now she loses power up hills and almost stalls. It's very weird and sudden. The oil, gas, etc. easy things are fine. I fixed the other weird "coughing" part with a new key, but this is very different-- no flickering red lights on the panel, just the feel of being out of tune. Suggestions? Would a carb problem suddenly surface 'overnight' after a 10day hiatus.

Darryl.Richman
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VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2183
Maybe a hole in one of the

Maybe a hole in one of the rubber diaphragms in the CV carbs? Your points timing could have slipped, or the condenser could have died.

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RickR90s
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Farmington Hills, MI
Joined: 11/28/2016
Posts: 63
how does it idle under that

how does it idle under that condition?

I did a tuneup on my R90s last fall. (new points and condenser) and it ran fine like it always does. Fast forward a few days and I'm on a group ride and the bike is running, but feels like the fuel taps are closing, exhibited by stalling and popping. And maybe about 1/2 power on the road.

I got her home and sure enough the points gap had closed to about .005" instead of the standard .016". The set screw wasn't quite loosed but could have been tighter.

I reset it, verified that the tiny lockwasher for the set screw was in place, applied a small dab of blue 'medium' threadlocker and it's been fine.

Something to check.

RickR90s

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gromulin
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VBMWMO #8889
El Granada, CA
Joined: 03/06/2015
Posts: 24
I'd drop the bowls and make

I'd drop the bowls and make sure nothing is plugging up the needle valves, make sure the floats are good, etc., before diving in deeper. Check plug wire connections at the coils under the tank...all the simple stuff first.

bstratton
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Joined: 08/10/2015
Posts: 87
assuming you went through the

assuming you went through the fuel delivery possibilities and checked your point timing/gap your symptoms could be caused by a coil going bad. I have seen them start to fail at first only when hot. Tough to diagnose without just getting a new coil and replacing each coil (one at a time).

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1971 R60/5
1965 R50/2 (project)
MA

waldoverkill
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VBMWMO #8020
Joined: 05/23/2011
Posts: 23
Choke?

I had this problem and found I had left the Choke on. Idle fine, Slow fine, Open throttle and coughcoughcough

Darryl.Richman
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VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2183
Me too - Choke?

When my lovely bride of 33 years and I went on our honeymoon to Germany in 1983, we rented a twin shock R100RT. The choke lever was down on the left side of the motor, not up on the handlebars, where it was on my R65. The second day out, we left our Zimmer Frei and went down the road, but shortly I knew the bike wasn't running right. I stopped at the next gas station and asked my wife, who speaks German (I did not), to ask them where there was a motorcycle workshop. It was only then that I realized I had forgotten to turn off the choke, and when I did, it ran great afterwards.

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mark_weiss
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Arizona
Joined: 11/16/2013
Posts: 170
I've seen breaker points

I've seen breaker points slip, condensers go bad, carb diaphragms tear, carb jets fall out, spark plug wires wear through, fuel filters plug, water in float bowls, carb-side choke levers lose their cable anchors, and probably more. All seem to cause "overnight" change because the effect was small during the last ride, with the bike fully warmed up, as the problem developed.

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Mark
qualitycycleservice.com

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