Just some random comments on the bikes
I should be making the initial parts order for this build next week (engine gaskets, rings, valve seals). Unfortunately I won't be able to get started on the build right away, as I have a couple XR engines builds that I need to get out of the way first.
In the mean time I've been riding the two DR's a lot recently on some short trails in back of my house. I've had the 350 for nearly a year and I almost never use the decomp lever because the engine is so easy to turn over. I've wondered if that might indicate engine issues, but I don't have the right size adapter for my compression tester so that hasn't been checked. But the new-to-me DR250 is nearly impossible to kick over without the compression release, so my guess is the 350 needs some engine work.
Despite the needed engine work, the 350 has loads more power than the 250, but that's not saying much. The 250 leaves a lot to be desired in the power department. If the difference between the 350 and the 440 big bore kit is as much as the difference between the 250 and the 350, I'll be a real happy camper.