My Z250 HPDI,2003,with 61hrs and all "updates" with Yamaha are up to date and has a rough idle. The engine at idle will shut down after about 4 or 5 mins of running,with occasional blue smoke out of the exhaust. When at running rpm(4000)the engine runs great. But after running and then shutting down for awhile, it takes 5 to 8 starts to keep it running. My technician has had the computer hooked up and found no problems.He checked the fuel pumps, the VST for leaks,the needle valve,and the fuel pressure regulator which all are working properly.He has also readjusted the throttle plate sensor. All fuel filters have been changed and new plugs(BRK6EKU)in place. He has been in contact with Yamaha for help, since this is not the only Yamaha he is working on with the same problem. So far they have not been any help and with the responce of "this is normal".I have seen enough outboard engines running and this is NOT normal.The technician also agrees this is not the norm. Any help I can get from this forum would be greatly appreciated. This is the best on the net
