Engine Seized - Please Help

[PeterSeymour]

Hello I have used this forum many times as a reference and had been meaning to register for a while. I purchased a 1999 GZ 250 about 4 months ago as my first motorcycle. I was hooked from the first ride and have put just over 2000 miles on the bike already. Unfortunately on my latest camping trip out to California I encountered some engine trouble early in the morning. After calling family friends I was assured it was just a fuel issue, and I should keep going to town. The oil gage on my bike, however, had noticeable condensation on the inside, though it still appeared to show that it was full of oil. I concluded that the gage was probably mucked up or somehow fouled and decided to add a quart just in case, and head into town. The engine appeared to run much better after the extra quart so once in town I bought another and added an additional half quart, just to be sure it had at least 1.5 quarts in the engine. After fully checking the engine for leaks and idling it while looking for smoke I started limping home, driving conservatively on back streets. I trained my left mirror on the muffler and stopped periodically to check for any apparent leak but I only had about 110 miles to go so I thought I could make it home. After about 60 of those miles, however, I heard a loud clunk and the rear while immediately locked up. There was no warning sign at all, no sputtering or smoke, but I was able to recover from the resulting skid safely and come to a stop. I again examined the bike to find no serious leaks and determined (after a long time examining the gage with a flashlight) that there was at least some oil sloshing around in the bottom of the engine. The engine however was at least mostly seized as I was only able to partially turn it over by pushing it up to speed and dropping the clutch (after doing this the starter would spin a little rather than just click).

I have a couple questions I was hoping to find answers to here, first of all what could prevent oil from getting into the engine (failed oil pump?). Second how could 1.5 quarts of oil (or at least a significant amount) burn up/leak in about an hour without any clearly noticeable leak or smoke? And finally now that I have a seized engine and very limited money do I try to fix the engine, buy a new engine entirely, or part out the bike and put that money towards a new one? I do work in a machine shop and have access to a lot of tools but I have very limited experience dealing with small engine repairs of that level, especially when there may be another underlying problem that cause the oil leak/burning.

I am sorry that is a lot to read but I am really desperate and I hope that someone here might have answers. All in all I am just grateful I made it home from the middle of the desert back to Phoenix and survived a potential crash - even if my motorcycle is shot. Still, not exactly the Thanksgiving I was hoping for. Thanks in advance for your help and assistance.