A couple weeks ago someone posted an older Yamaha XS400 for $600.00.
A one owner bike with a mere 2784 original miles on it. The down side was that it has sat dormant for many years with a couple gallons of stale gasoline in the tank.
UPDATE: The oil filter bolt / pressure tube removal ended up being an "afternoon project"....as it was REALLY "nature welded" into the engine block. I fit the proper 12 MM "six sided" spanner wrench first off.....then went to a six sided 12 MM socket.....then to a twelve sided 12 MM socket....all slipped while attempting to loosen bolt. In desperation, I "drove" a slightly smaller 7/16" twelve sided socket on the bolt but it slipped also. Then I used a tiny Dremel Cut-off wheel and cut the mangled bolt head off....then drilled a small hole in center of bolt. Three different sized screw extractors were then used in an attempt to loosen the bolt. All simply slipped and gouged out more metal. Finally decided to attempt removal with a cold chisel / hammer. Used a "miter" type Dremel Bit and enlarged the hole, then cut slots in the perimeter so I could use a chisel. Finally was able to "break" the damned thing loose with the chisel. Took about 3 hours total to remove it, but no collateral damage....yay!
The new oil filter bolt / pressure tube is a Yamaha OEM bolt. The replacement uses a larger 17 MM bolt head, rather than the little 12 MM head. I used a bit of "anti-seize" on the threads and did not over tighten.
I rode the bike in the neighborhood a few miles and eventually had a flooding issue with the left carburetor. ...Pulling it apart I found one of the float bulbs full of gas. The solder on a seam must have breached when heating the float pins. Rather than screw with it any longer, I ordered one new float assembly and two new needle valves / seats. Carb removal is now a 15 minute process (practice makes perfect) so no big deal.
Ended up using Apple Cider Vinegar for 5 more days to de-rust the fuel tank. The rust vanished after that time frame. I flushed the tank well, then added some baking soda / water to neutralize. Then added some "Marvel Mystery Oil" and sloshed around. Tank interior came out looking good. I installed an in line fuel filter for insurance to catch any rust remnants which might surface.
This Model Yamaha used a "vacuum operated" fuel tank petcock. These type do not have an "OFF" position, but rather are supposed to shut automatically when engine vacuum ceases. I've had a few of these over the years and without exception, with age, none of them have worked properly. This one is the same, so I added an additional "in line" petcock I had laying around for insurance. I found an exact configuration petcock on eBay, without the vacuum assembly, so maybe I'll buy one at some point.
Done for now.....used some light de-greaser in all hard to access spots and gave the bike a good cleaning. The little windscreen which was on the bike did not fit well so I removed it. I decided to fit it to my /5 BMW.