hesitation problem yamaha g16

[2000yamahag16]

have a 98 yamaha g16 with a hesitation when gas pedal is pushed to the floor but it runs great other wise if i ease into the pedal it will not hesitat ..... i have built a brand new g16 motor in it everything is new and the correct parts for 98 yamaha g16

[slonomo]

My first inclination is to say it's carburetor related, or possibly fuel supply. Is the carb a genuine Mikuni?

[crash12888]

I've had this issue several times usually after the carts sit for the winter or similar. It has varnish build up in the jets.
The carb needs to come off and taken apart and soaked in carb cleaner to remove it, spray cleaner won't do it.
Cleaner comes in a gallon from any of the box auto parts stores, has a little basket in it although it is a little pricey at around $30 a gallon.
Need to remove all jets and screws and soak for about an hour to really get it out.
Reassemble, make sure the filter box is properly sealed and should be good to go.

Also, while it is off, check the insulator block behind the carb for cracks.

[raydhd]

Originally Posted by crash12888

I've had this issue several times usually after the carts sit for the winter or similar. It has varnish build up in the jets.
The carb needs to come off and taken apart and soaked in carb cleaner to remove it, spray cleaner won't do it.
Cleaner comes in a gallon from any of the box auto parts stores, has a little basket in it although it is a little pricey at around $30 a gallon.
Need to remove all jets and screws and soak for about an hour to really get it out.
Reassemble, make sure the filter box is properly sealed and should be good to go.

Also, while it is off, check the insulator block behind the carb for cracks.

I second this whole thing. Right after the gummed up carb issues can't say how many of those insulator blocks I had fail. Someone here had suggested part of this was using the K&N filter that does not support the carb like the stock unit does.