Carb adjustment

[casey1240]

I have a 1994, 50 hp, Yamaha, that has never been touched mechanically and this year when I started it up, it fails to idle for any length of time. When I say lenght of time, it will idle for about 1 minute and then quit. Just like it can't bring in new fuel to keep going? It starts up immediately thereafter but again will only idle for the same time period. This model has 3 carbs with an rpm adjustment for all 3. The lower carb seems to have a screw for the mixture, but I see none for the other two. Do these motors idle off from on carb? I have replaced the fuel, checked fuel filter, tightened screws and installed new plugs with no apparent change. Your thoughts? Thank you.

[99yam40]

pilot jet/passages are plugged.
carbs need to be pulled and cleaned properly and then do the link and sync after reinstalling carbs

[casey1240]

Ok .... can you reccomend a specific repair manual that would address these carbs? Thank you for your response.

[rodbolt17]

the yamaha factory shop manual is a good one.