Yamaha carburetor issue

[Danfromvan]

hi
I have a 1993 Yamaha T9.9 ELHR 4 stroke

this motor will will start on half a crank
idles like a kitten purring
runs WOT BEUTIFULLY

ISSUE :
shen accelerating it coughs ,sputters ,backfires though the carb
i don’t think it can get sny cleaner
replaced a wack of parts
been trying to order a new carb and all I can find is a 2 stroke model
tearing my hair out over this
I’m a carpenter not a mechanic but I can usually figure these things out

any suggestions ??

thznk you

 

[KLFrank]

Look into the fuel filter. It will idle smooth with little gas. It will run WOT with little gas. The fuel is starving and running lean, restricted by the fuel filter. On acceleration is when the demand for fuel is needed. Just a thought. Hope it helps

 

[99yam40]

4 stroke motor backfiring thru carb means it is firing a cylinder with an intake valve open