Question about 1988 BMW K 100

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Hi, I have a 1988 BMW K100RT. It's been sitting in the shed unstarted for 12 months. Today I dumped the old fuel and put half a tank of fresh fuel in, installed a brand new battery, oil filter and engine oil, the bike tried to start very strong and was cranking well, although does not start. I checked the plugs and spark is getting to all plugs, the plug leads are in the correct firing order, and the plugs are getting wet from fuel. There is also a smell of fuel from the exhaust as it attempts to start which is a good sign. I'm thinking this has to be electrical or fuel issue, but all signs are pointing to electrics and fuel being fine?

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Removing all the old fuel is a good start, the tank is only one point, you also need to flush the old fuel out of the total system including the fuel rail and pipes, to ensure fresh fuel is first into the engine.

Posted on Aug 17, 2014


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Posted on Jan 02, 2017

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SOURCE: fuel pump

Can you hear the pump when you turn the key on normally? When the pump on my old FJ starts up with the key, it makes enough racket to let you know. Your bike is alot smarter than mine, it might be able to tell that the lines are unhooked and preventing the pump from working as a safety thing. Is the fuel line made of or contain any metal? It may need to see continuity in the fuel system to allow the pump to operate. Or some other parameter is not being met with the lines disconnected. Have you tried thumbing the starter with the lines off? The bike might only pressurize the system when the engine is starting or running.... actually, this is my best guess now that I think of it.

Posted on Nov 20, 2008

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SOURCE: My 87 k100rt bmw left hand indicator switch doesnt work reliably

The switch may just need cleaning. Remove the switch unit from the handlebar and spray a good quality switch and contact cleaner into it. I had a similar problem with the indicator cancel switch. Do not use WD40. Get the switch cleaner from an electronics shop.

Posted on Apr 22, 2010

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