My 1996 80hp Yamaha 2-Stroke Outboard Continuing Saga

I have an 80hp 1996 C80TLRV 2-Stroke Yamaha Outboard motor that I can not get running right. I have posted previously on this forum and taken advice, however, the problem has not been solved yet. The issue is that the engine idles great. I can idle out of the marina and as soon as I give it gas it dies.
Been fighting this issue for at least 6 months.

Most of my changes have been in the fuel system. To date I have done the following:

• Purchased a 5 gallon fuel tank so I can isolate any problems concerning the fuel line from the under the deck fuel tank.
• Purchased an OEM Yamaha fuel line with the bulb that runs from the auxiliary fuel tank to the engine.
• Replaced the male connector on the motor that the new fuel line connects to.
• Replaced the fuel filter assembly.
• Replaced the fuel pump.
• Rebuilt the carburetors.

Almost everything in the fuel system is new with the exception of the small hoses interconnecting the fuel filter, fuel pump, carburetors etc.

On the electrical side the only thing I have done is to replace the spark plugs. The compression, the last time I checked it, is great so I do not think that is the problem.

Anyone have an idea what my problem could be?

Thanks in advance

Sounds like it is too lean at idle.---Try opening low speed mixture needles 1/4 turn at a time.------Or throttle plates are opening too early.--------So operate / bump the choke when you are giving it gas.----Or have an assistant spray fuel into carburetors when opening throttle.-----No $$ spent so far in a little testing.

racerone said:

Sounds like it is too lean at idle.---Try opening low speed mixture needles 1/4 turn at a time.------Or throttle plates are opening too early.--------So operate / bump the choke when you are giving it gas.----Or have an assistant spray fuel into carburetors when opening throttle.-----No $$ spent so far in a little testing.

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You da man racerone!!! I opened the low speed mixture screws (3 of them) 1/4 turn each and the boat took off like a bat out of hell!! Ran perfect for the 1 hour trip. I am sure the low speed mixture screws need to be further adjusted for peak performance but I was happy with the outcome you provided. Thanks again!!

?---6 months and all those parts and effort for what appears was a simple fix ??-----Good on ya to follow the " no money " spent path of trouble shooting.

racerone said:

?---6 months and all those parts and effort for what appears was a simple fix ??-----Good on ya to follow the " no money " spent path of trouble shooting.

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Yes I did spend quite a bit of money and time but I feel better knowing I have new parts on a 23 year old engine. But yes. I definitely could have gotten by spending much less money.