BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

A friend and I were doing a test ride on a new bike I bought to fix up and use as my daily beater last weekend. After putting brand new spark plugs in (and fixing up a bunch of other stuff unrelated to the engine) and going for a 30 min in the heavy downpour, the engine cut off at 45mph but the dash stayed on and battery was good.

we pulled over and tried to start the bike multiple times to no avail. the bike just wouldn't ignite, it would crank over and over but wouldn't spark and run. We decided to take a look at the spark plugs. after taking off the right side out we noticed it was completely black and dirty (after only after a 30 min ride) and the left side looking used but still very clean. Deciding that swapping them around might solve the issue and get us home, we gave it a try. The bike started up right away and I rode away.

the bike feels very rough, it shakes, has a loud clutch rattling noise if it's in neutral and clutch lever isn't pulled in, has issues shifting into first at some red lights, and only pulls away if I'm revving past 4k rpm. This is my first BMW R1150 and it's heavily used with 42k miles and three previous owners before me with not much care into proper maintenance. So I don't really know what to look for with the issues that it has. Any help would be greatly appreciated. Thank you.

My first job would be to replace the (expensive) plug-cap-coil units. (stick-coils).

If they're the originals, then they're not very resilient and can fail very easily.

I used to have to replace one or two every year or so - until I started coating them with High-temp (silicon) grease. It makes them easier to remove, and (more importantly), gives them an extra layer of weather protection. The newer coils (grey coloured) are also better than the older (black) units.

This may also help with the rough running.

Sounds like the bike needs a good service :
Oils changed
Filters changed
valve clearances
TB Balance

Should be right as rain after that little lot.

You didn't say the year of the bike. If it's 2003 or older it's a single spark (one plug pet cylinder) and had a single ignition coil under the tank. They seldom if ever fail. If it's a dual spark (two plugs per cylinder) then the primary plug......one in end of head.....has an integrated coil in the plug wire cap. They are a common point of failure. Riceburner's advice is spot on.

The way you described the failure in the rain makes me think of the Hall Sensor failing. It's located right behind or under the crank pulley (front of engine). They've been known to fail when running thru a heavy rain. A lot of water hits that engine cover. The Hall Sensor triggers the spark.

Thank you riceburner and towerworker. I'm sorry I forgot about the year. it's an 02

Also check out the throttle wire on each side. They are maybe not in right place on the throttebody. Normal if the gastank have been taking of.

maybe hall effect sensor failure....or maybe not: http://forums.bmwmoal.org/showthread.ph ... or-Failure