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Discussion Starter · #1 · (Edited)
My 87 K100RT with 45000 km has run great in the last year and a half that I have had it.

It started running a bit rough around the 2000 rpm mark about six months ago.
I used Lucas injector cleaner a couple of times and it seemed to help until last month.

Starting last month it started to lack power at 2000 rpm but then woudl kick back in once I got to 2500 or 3000.

Now it is much worse.

It starts rough
Backfires quite a bit when cold.
As well, it stalls often at idle and lacks power at speed.
If I hit the sweet spot with the throttle the power is fine but if I twist it above that it bogs down and feels as if it is flooding. (ie no power)
Also, my mileage has gone down 20%

I have:
Replaced the plugs (they looked fouled)
Replaced the air filter
replaced the fuel filter
replaced the Z shaped crankcase hose (it was cracked)
Looked for any cracked hoses but have not found anything.
Have run redline injector cleaner through.
Have run a can of Seafoam cleaner through the gas tank.

None of this has seemed to make any difference.
Any idea what is causing it (injectors maybe?)
Should I pull the injectors and look at them? If so, what am I looking for and how do I clean them manually?
Any recommendations for how to fix it from the big brains on this board? :confused: :)
Thanks guys.
TC
 

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welcome

I have heard of hooking up your injector to compressed air or fuel if possible, and cranking it up to 60 psi while taking 12v or so and connecting it on off on off repeatedly to open the injector(or just leave the electrical connections on and hit the starter). i think they let the injector sit in fuel for a few hours before to loosen everything. maybe you could just soak it then put it back on the rail, hit the starter and see what sprays out. Injectors might at to come off the rail though without anything holding them though. anyway this would give you an idea of how much gas our getting at idle.
 

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Discussion Starter · #3 ·
Update!!

It was the plug wire to the number 4 plug.
I tested the resistance and it did not match the other three.

I replaced the wire and she is purring again.

TC
 

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welcome

I have heard of hooking up your injector to compressed air or fuel if possible, and cranking it up to 60 psi while taking 12v or so and connecting it on off on off repeatedly to open the injector(or just leave the electrical connections on and hit the starter). i think they let the injector sit in fuel for a few hours before to loosen everything. maybe you could just soak it then put it back on the rail, hit the starter and see what sprays out. Injectors might at to come off the rail though without anything holding them though. anyway this would give you an idea of how much gas our getting at idle.
I notice you posted this on October 8 2008 . Just joined today and don't see a lot of action on the site . I thought I post a reply to this 13 year old post . Or see if anyone at all replies . ^ days ago I bought a 1991 BMW K75RT that runs beautifully . Years ago I had a 1978 motosport RS1000 It was a great bike, but I left it siting in my garage for 20 years unridden, and sold it last year to a guy who is restoring it . I'll add a photo of my red 1991 K75RT and one of my white 1978 Motosport .
Tire Wheel Cloud Sky Vehicle
Tire Wheel Sky Fuel tank Vehicle
 

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2009 K1300S, 2017 S1000R & 2021 Vespa Primavera clown paint job
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If you want to do the other wires, Euromotoelectric has them for a lot less than BMW, caps too. If you inspect the ignition wires and find a gray spot about 3 or 4 mm across with a black dot in the middle that is where it has failed and leaking to ground.
 
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