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

A kind of ridiculous question... PO wasn't very attentive to this bike so after removing the tank, it looks like it has never been cleaned in the past century. I really feel like dumping lots of soapy water and spraying streams of water on it. Is there a real danger of doing so? The ABS stuff and electrical wiring are underneath so this worries me. I was planning on cleaning/drying each contact after and applying dielectric grease. I also have compressed air so drying everything after is not an issue. I am worried that I can permanently damage something with the water, despite drying it after. Thoughts?

PS: It is also quite filthy under the seat but this doesn't worry me as much.

I wouldn't chance it. I would prolly use a multi cleaner like Simple Green or something and let it set a few minutes at most. May take several attempts to get it lookin good though!
While you have the tank off, I would take a good look at the zip ties that are commonly over used and overly tight. I found several that really were not needed at all and some I just cut off and replaced with plenty of slack without being too loose.

I'm with the other posters on this; some type of appropriate cleaner, soft cloths, toothbrushes work well for some things (other than teeth of course). I wouldn't use water or air with any type of real pressure behind it. If you use any kind of aerosol electrical cleaner, then be sure it doesn't melt plastics. Think of all the hours that it took for that gunk, grime, etc to accumulate in there, and take some time to really get it cleaned up well.

Disconnect negative battery terminal before any cleaning or poking around. I doubt high pressure air (from the homeowner's style of compressor) would hurt anything but high pressure water is a no-no. Under the tank is kinda like under the hood of your car, everything gets road grime, grease and some water. I have pulled my tank and gently cleaned but I exercise a lot of caution around the wiring harness and any plugs/connections. Take your time and be careful.

Remove the battery and wipe it all down.
I use industrial citrus-based cleaner.
You can disconnect the forward wiring harnesses to allow better access to the front subframe.
With both tank and seat removed, you have easy access to almost everything, except the LHS wiring harness, under the iABS module, and tight sections behind rear subframe near air box and fuse box.
I found that removing the iABS permanently really helped with housekeeping!
I also found a dead bird under the tank once upon a time: that portion of the R1150R begs occasional inspection.

I hear you guys! I was actually more worried about water getting into tiny vents (not sure if the 1150 has this but my 1200 does) of the ABS electronics module. With water ingress, it will take forever to dry by itself. Much longer than for the water to do real damage on the electronics. Maybe I'll use compressed air for the meantime, being careful on where and how near I point the air gun.

Thanks for all your replies. Appreciate it!

My thoughts are that this is one of those jobs that I would only do by performing a full stripdown of all components and cleaning them individually as required.

I just did this.. not perfect, but it looks a lot better. simple green, diluted. soft brush. and air gun.

Darn I can foresee it's a lot of work coming...