Re: finicky 2000 50 hp 4 stroke?
Thanx for all the replies .... I have pretty much covered every one of these points and more. Shop rebuilt the carbs a couple of years ago at about $200 a kit (that's times 4...plus labor), cleaned and tuned the carbs - within a few months - happening again. I have drained and cleared the tank, used a secondary portable tank, replaced all the fuel lines, removed the quick disconnect and "hard-wired" the gas line straight to the motor, checked water filter (do that on a regular basis anyway), REPLACED the water filter assembly and the filter itself with all new.... filter on the motor is always clean. Yes the plugs on the carbs are removed and the low speed adjustment screws are accessible....
My best friend is a retired Yamaha mechanic - have finally talked him into pulling the carbs and checking them...TWICE - he cleans the carbs and adjusts using a mercury guage.... runs great when he's done and for a month or so... I hate to keep asking him to pull them over and over... both he and my dealership - who he worked for for 26 years says Yamaha has ALWAYS had trouble with these motors - linkage too complicated - too hard to adjust..... something about jets being so small even the tiniest foreign matter fouls them. We did find some corrosion in one of the carbs that was malfunctioning, evidently smal particles broke loose and blocked a jet... Spark is good.... sometimes when running you can pull a plug wire on a cylinder... no change - gotta be fuel or carb... I dunno guys, just very frustrated right now, I have had this motor from new, it has always been had issues off and on, but lately getting worse. Was wondering if anyone else was having these problems and maybe discovered a magic bullet fix... motor is 12 years old but garage kept, immaculate.... Thanx again for the input.
