From what I understand, Yama drop'd the 250 due to some problems that they had with the 03 and 04 motors.
I have a 03 250 HPDI on my boat, and have been concerned about the problems. I got lucky and passed the golden threshold so my motor should be go to go. Yama rep here in NC said that if it were to have problems, they'd of happend within the first 40 hours of operation.
The problem? #2 cylinder oiling and a CPU problem. There is a service bulletin that was put out by Yama to fix them, but unfortunately, some folks get them before the bulletin... so alot of unhappy customers,,, but Yama did pony up the warranty and replaced heads and in some cases complete motors, but many lost trust in the 250's and 300's (HPDI).
the 300 HPDI had a problem with water ingestion via the cowling. This too was corrected via a service bulletin... but like the 250, folks felt reliability was shaky.
I'll be honest, I was very worried about it all the way up to the 80 hour mark, but now I've got 118 hours on her and I think it's a good motor, does what it's advertised to do and I'm happy with it.
If I had to do it over, I'd slap twin 175 Suzuki's on the back.
Just my .02