I have a 05 300 Trx sport
It starts fine but once the throttle is applied more than 1/4
The bike sputters and wants to turn off if I keep the throttle 100%

Any ideas would be appreciated .

 

its a carb issue... take it apart and clean it good and put it back together, you might condier a rebuild kit..

 

You have a clogged jet, clean the carb.

 

i rode around on my 300ex like that thought one day and i looked down and my choke was on

 

yep ^^ clean the carbs

 

It may be the timming? Try carb first....Good Luck!

 

check ur timing pull the timing plug out the case line the t up with the notch in the case on the cam gear there are three marks two lines and a dot the dot points up and the two lines should sit level with the head if its in time check your carb again i have one doing the exact same thing thought it was jets cleaned them didn't change a thing. on the side of your bowl on the carb there should be a primer try pushing that while your trying to go if it runs while you pump it you got a carb prob rebuild it if it doesn't i would check my timing anyway hope i helped ya now everyone knows what i got goin on any suggestions