My sons new TRX90 coughs and dies sometimes when he nails the throttle hard from a dead idle.It has been to the dealer several times and it seems lean. we have tried enlarging the slow(pilot) jet(no larger sizes available),changing the needle clip position(no other needles available),new float(non-adjustable).The air/fuel screw is adjusted after every change.Other than this problem it seems to run fine.It does it warm or cold. The dealer had 2 others on the floor and they did it also (not all as severe).
Anyone else have this problem? any suggestions.

 

Just about all small Honda's do that. It is caused by the long intake. The only thing to do is turn the idle up higher, advance the timing, and use gear oil or chain lube on the air filter.