I do hope that you plan to ride with your friend on the WR250, to Key West and back on the nearly stock and standard KLR this year. And modify next winter. A trip like that will give you an over-all better sense of the KLRs capabilities and your desired alterations.
Well, I have considered that option but I have a few concerns that make me want to proceed with the swap ASAP.
First off, I have other bikes to fill my 100% on road, and 100% off road needs. This bike will be used as a touring/travel bike, so inherently reliability is my first priority. The previous owner said the speedometer stopped working around 2 years ago, he rode it for a whole additional year and parked for another year after the speedo broke at 35,000 and some change. I have no idea how many miles are on this engine. He had never heard of a doohickey or thermobob which scares me too, to top it off the engine oil level was below the sight glass when I bought it. Took about half a cup to bring it back up. The engine runs great, make a plenty of low end grunt (doesn't smoke) but has 2+ year old oil in it and I have no history of valve adjustments or any other maintenance. Bent radiator, no rad shrouds. Taking off on a 2,500+ mile ride on that many unknowns makes me nervous. If the cams and journals aren't galled up and the engine isn't consuming oil like my two stroke I still have the doohickey, thermobob, valve adjustment and other odds and ends before I'll even begin to trust it. For that kind of money I can add a few extra hundred and pick up a wrecked ex500 and swap it. I have access to all the tools and resources I'd need for the swap.
So that is my dilemma, I don't have anything against the klr power plant, I prefer carbs for reliability and trail side servicing if necessary. I just don't know a thing about this engine, the bike has lived outside for the majority of its life and the plastics reflect that. The poor condition makes this bike a good candidate for a swap in my opinion, I'd basically swap the motor, add a trail tech vapor maybe a few farkles and just ride it. Another thought was to clean the bike up and turn it for a profit and get another KLR in better shape!
Please share your thoughts, I am open to suggestions. I just want to think through whatever I decide to do. Thanks.