Mon Apr 06, 2009 10:33 pm by FlatHeadSix
Chris is absolutely right about the flush procedure; don't ride the bike! I will go even further and say don't even start the engine.
If you read any of the excellent documents that were published specifically for the military flatheads (the Army "TM" manuals) they will all tell you that flushing the oil tank was a static procedure. They did not use a kerosene based proprietary flushing product, they used pure KEROSENE, and they did it without running the engine. As Chris mentioned, it required some kind of mechanical means to help dislodge the sludge and get it into solution so you could drain it out of the oil tank, a stick, agitation, whatever.
Run the engine until it reaches operating temperature with the old oil in it. If the scavenger pump is doing its job it will pull most of the dirty oil out of the sump and return it to the tank. Drain the tank completely. Add your solvent of choice (kerosene or proprietary engine flush) and slosh it around as best you can, use a stick to stir it if you like, and drain it completely. Refill with clean oil and repeat at normal change intervals. If your cases have a drain plug (some don't) you can remove the plug and drain the sump after the initial warm up and before, or while, you do the tank flush.
The best advice is to change the oil frequently and when you ride the bike you should ride it long enough and far enough to thoroughly warm the oil so that it circulates and gets hot enough to flash all the moisture out of the system.
mike
