yamaha 2006 90HP hiccups at idle speed

I just bought this 90HP and found that it hiccups at idle speed. It also will start up fine but after 15-20 seconds it hiccups and shuts off. Restarts ok and when it is above idle speed it runs great. Only does this at low speeds around 800-1000 RPMs. Runs fine at top end.
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I cleaned the carbs, which looked clean to me other than some corrosion in the middle carb bowl and around the fuel enrichment pump assembly. I*disassembled the assembly, cleaned it and tested the electrothermal*valve resistance and valve height per manual. All looked well.
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I*adjusted the low speed jets and*put in new plugs. After putting it all together again I expected my hiccups to go away. That isn't the case. I still have the original problem. However I gained a*lot of experience with the Yamaha engines.
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Does anyone one have any suggestions on what to do next?*
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Rich*

did you use new parts?

Just the smallest amount of debris will restrict the idle jet and cause the lean miss you are experiencing. It has to be super clean.

Thanks for the info. Looks like I will have to clean them again. Anyone have a favorite carb cleaner that I can use to soak them in?

no soaking in anything

i use vinegar and water with dawn soap
in a heated ultra sonic cleaner

You may have a problem with the reeds. If so the engine will run rich and probably puddle fuel in the carb barrel or in the airbox. There is a simple test, remove the front of the airbox and run the engine off idle while carefully observing the front of the carbs, you're looking for tiny droplets of fuel to shoot out the front of the carbs. They are very small so keep watching and also look for fuel to puddle in the front of the carb or even drip out. If fuel comes out the front of your carbs the reeds are not closing properly. Replacing the reeds is one step further than cleaning the carbs so you won't be in that much trouble if they turn out bad, you can do it. Also make sure that the little red switch on your enrichner is in the correct position, there is a sticker on the aibox that illustrates this. In other news, there is a black plastic electronic box on the driver side about the size of a pack of cigarettes. This part electronically adjusts the ignition timing. You'll want to make sure your alignment marks correspond and you may even want to disconect the ball joint linkage so you can move it manually to be sure that it moves smoothly without any stiffness or hang-ups. The hiccups at idle are usually a result of a rich running condition. Oh yea, I forgot, did you happen to notice if the needle valves in the carb had a ring groove worn into the tip? I've been seeing this a lot in recent years, probably due to alcohol. They too can cause the engine to run rich. The correct airscrew settind for this model is 1 1/4. Timing at idle is retarded 8 deg. +/- 1 deg. I think it's running a little rich, you could also try new plugs then take them out and see if they (or one) looks rich. Best of luck.