Just got a 26’ Sailboat with a '98 9.9 Yamaha. Prior owner said it had the carb replaced and engine tuned up a few months before purchase. Shortly after purchase I motor sailed it for several hours and engine would run ok.
Starts fine after a couple of tries; However, if I leave it idling for a bit (several minutes), and try to accelerate it will stall. A few days ago, I was taking the boat from the boatyard to the marina and could not keep it running or accelerate. After many attempts I was able to make it run if accelerating slowly and restricting the air flow to the carb until it reached high RPM's.
Yesterday it had the same symptoms; when I removed the cover, the engine would run fine. Once I get it to accelerate it runs OK with no misfire or roughness.
Checked plugs and fuel filter and those are OK. Resistance for the Thermo-electric valve (starter) read 10.4 ohms.
Any suggestions?
Thanks!
Starts fine after a couple of tries; However, if I leave it idling for a bit (several minutes), and try to accelerate it will stall. A few days ago, I was taking the boat from the boatyard to the marina and could not keep it running or accelerate. After many attempts I was able to make it run if accelerating slowly and restricting the air flow to the carb until it reached high RPM's.
Yesterday it had the same symptoms; when I removed the cover, the engine would run fine. Once I get it to accelerate it runs OK with no misfire or roughness.
Checked plugs and fuel filter and those are OK. Resistance for the Thermo-electric valve (starter) read 10.4 ohms.
Any suggestions?
Thanks!