So I was pulling my 2007 990 SD intake and emissions apart during a Rottweiler install, got the throttle bodies off, and got a nasty surprise when I turned them over. I'm pretty sure it's a combination of settled dust over the years and/or the old air filter eroding. It didn't seem too badly stuck on the metal, but I haven't started cleaning in earnest yet. The throttle bodies I'm not too worried about, some TB spray and a soft rag should do the trick. Am more concerned about the intakes and whatever has settled inside the head. I can spray and wipe the intakes of course, but what about the head? Am thinking about things like too much liquid hydro-locking, crud scraping the cylinder walls, etc. Any advice or suggestions?

FYI- the bike sat inside a climate controlled dealership for almost 10 years- I got it with about 20 miles on the odo. Thanks!

Are you in New Orleans?

Erm, no... why do you ask?

Was there any oil/water sludge in the air box 'cos that could be 'just' the crankcase breather pumping out excessively due a failed balancer shaft seal?

Airbox is clean, going to see how the throttle bodies clean up at least.

Looks to be some very extreme gasoline varnish. I'm guessing from sitting on the showroom and getting started every now and then but not run for years. Got a wrench bud that has some throttle body specific cleaner, and going to try that. I've never seen varnish with an almost fuzzy coating to it, hopefully I can get enough cleaner into the head without too much trouble. I certainly plan to dump a can of seafoam or similar into the tank after I empty it, swish, soak, and dump it out. I'm also hoping another bud still has his fuel injector cleaner kit, maybe not totally necessary but if he still has it I'm sure it can't hurt.

You might want to pull your fuel pump out of the tank and check it along with the two filters inside.

You can get replacement filters for cheap here:

Making some progress, AcDelco carb conditioner made quick work on the throttle bodies. The intakes are another story though. I think one of the old oil masters, (Rembrant maybe?), varnished this stuff on for the ages. Mineral spirits and brake/parts cleaner is finally doing it. I pulled the fuel pump out of the tank, haven't looked at the filters yet, but will replace them in any case, thanks for the link.

To catch what?....

2 cans of carb cleaner, the last of the ACDelco spray, and 1 can of lacquer thinner took care of most of the intakes and exhaust sides. I was sending *huge* chunks of carbon all over the place when I would blow out the exhaust ports. There is still some crud in there, but hoping that it will dissolve/burn out with some quality ride time and fuel system elixir, (have had pretty good results with Yamaha Ring Free in the past). I don't think I can get much more out at this point without pulling the heads and doing a complete disassembly.

At least I will do some (temporary) damage to the mosquitos in my yard when I finally get it back together and running!

Gotcha, now in context thanks!

Have a Rotty breather blank kit on the way already. I was going to stick with the routing the breather tube back into the box, but I had other thoughts over the weekend. No more crankcase fumes back into the intake.