T9.9 will not run

[sherwin]

For the second year, I have taken my T9.9 out of storage and it won't run properly. It was serviced
last year by running all the gas out with Stabil added to the last bit. Also, opended the drain screw on the carb to let out remaining gas. Now the
engine starts up and runs for a few seconds, and dies. This is fresh gas to which I have added a small amount of Sea Foam. I pulled the carb and poked a fine wire through both jets and the engine
only improved slightly by running very roughtly for
a few minutes. This engine is getting to be one pain in the neck. It is almost new with less than
50 hours running on it, although I bought it in 2002. How can Yamaha put out such a trouble prone
engine?

[boats.net]

The small engine carbs are hard to clean, try soaking it in Sea Foam to clean out jets and passages and then wash out with water.

[sherwin]

My mistake was thinking there are only two jets on the carb. There are actually three, and I missed the intermediate speed jet because it was hiding under a plastic cap. My mechanic showed me how to remove and clean it. The engine finally was able to
run after putting it into gear. It was still a bit rough running, but after about a quarter hour of running it in gear, it smoothened out. I had put Sea Foam in the tank from the very start. My mechanic was apprehensive about any product not made by an engine manufacturer, because of liability issues that make their products more reliable. He recommended a Mercury product QuickSilver or QuickClean, one ounce per 4 gallons. He maintains that treatment will keep the carbs running even after lengthy layups. I have an inline filter on the gas tank and the engine has it's own filter, so that should keep some of the junk out of the carb. I would recommend Yamaha putting some kind of one way air
valve on the carb with an accompanying compressed
air can, so you can blow out any excess gas from these jets. That might prevent all this frustrating unmounting and remounting of the carbs
and cleaning of the jets. Although it has not happened yet, I am worried about losing engine power in precarious places, like in front of a bridge.
I keep my anchor ready to go, just in case.