2002 50hp 4 stroker

[Bay Catt]

Bought boat/motor with 18 hours on it in 2004. Has 90 hours now. Ran great till recently. Changed Seperator to a 10 micron, Clean screen in fuel bulb,then trailered boat 500 miles to fish Cheasapeke. Ran like crap. Fond #2 plug was loose, replaced all plugs. Rpms at idle range from 7-9000(should be 10500), stalls on exceleration and when dropped back down into revearse, top ends at 4300(red line is 5500, however I have it set up at 5000. Leaning toward carb rebuilds but wanted some input first. Anyone have a tech manual for a F50TLRZ. Yamaha sells them at $60.

[slim]

i will tell you this much. a 4 strokes carbs is not a job for the average person. they are more complicated and once you have them back on, you have to install a vacuum guage to the intake to sync the carbs.

[Bay Catt]

Thank Slim, Just read my own message and found typo's and mistakes. Motor is a 2001, Z signafies year. I was told at purchase it was a 2002. Idel rpm is 7-900, which is correct for motor. Also since last posting I have drained the fuel tank. Had about 1 quart of water in it and lots of fine black particals. Forgot about filling up on the penninsula side of Virginia. That had flooding down there from a bad storm 4 days befor I filled up. Contanimated gas. Any good advice on flushing tank and fuel system would be helpfull. I want to flush then try some new gas befor I go into carb rebuilds.