Trouble starting yamaha f40bet carb version

[Disschord]

Hi I am having trouble starting my yamaha f40bet it's the carb version

The engine has trouble starting it turns over without firing for ages.
I turn her over for 5 seconds at a time then leaving her for a while and repeat.
After 5 or ten minutes of this she will start to fire then after a while longer she will run but rough.
Once warmed up she runs fine and will run fine all day but come back tomorrow and I'm back to square one.

I always use fresh fuel and run the carbs dry when done.

I checked the plugs they are fine but changed them anyway.
All 3 plugs are sparking fine.

Any ideas what I should look at next?

Many thanks

[boscoe99]

It is the carburetors. Arguably the most complex and troublesome set used on any Yamaha.

If it is just a cold start issue (you are a lucky man) then you might want to look at the fuel enrichment system aka Primestart.

Is the accelerator pump working? As a band aid approach you can quickly advance the throttle several times before you attempt to start the motor. It will provide some additional fuel to help get the motor started.