I have an 2003 60 hp yamaha that has been acting up .It started off with a slit skip or miss every now and then over the summer and now its running terrible , hard to crank and wont get past 3400 rpm . If you ever get it going , it will level out as long as you don’t touch the throttle . I thought it had some water/trash in the fuel filters …changed filters along with the plugs and it didn’t help . When it first started , around July 4th , I thought it was in need of some minor maintenance. I don’t want to run it much to trouble shoot the problem with it running like this because if its running lean , it may burn a piston .I haven’t ran it a lot like this and I normally crank the motor and let it run in the yard with the muffs on it about every 2 weeks just to move fuel thru the carbs . Sounds like a trip to the repair shop .
Sounds like time to have the carbs cleaned
Shock treatment with Seafoam on portable tank and if that doesn’t get it out, then rebuild carbs with a soak.
Rick
23 Center Console
Twin 140s
“Dirty Money”
Thanks
Got the same motor and had the same issues,did the seafoam thing to no avail,ended up the carbs needed a re-build.Motor purrs like she always has now.