Help with Grizzly 660

[google7]

Hey Guys

I've got an 05 Grizzly 660 it's got a jet kit and k&n air filter installed it also had a hmf exhaust but i took it out cause it was just to loud it runs great untill it's under heavy load

when it's under heavy load it sputters like the limiter kicks in

if I hammer on all the brakes and then push on the throttle till it's full out then it starts to sputter going up hill and in mud

it does it in HI and in LOW gear

what could be the issue

thanks in advance for your help

[CRAZYKIWI]

Hey Guys

I've got an 05 Grizzly 660 it's got a jet kit and k&n air filter installed it also had a hmf exhaust but i took it out cause it was just to loud it runs great untill it's under heavy load

when it's under heavy load it sputters like the limiter kicks in

if I hammer on all the brakes and then push on the throttle till it's full out then it starts to sputter going up hill and in mud

it does it in HI and in LOW gear

what could be the issue

thanks in advance for your help

does it run ok tho with the hmf??

Cos if you have the std muffler back on it will be too rich now??

[google7]

It was already installed with the HMF and yes it ran awesome so maybe it is getting to much fuel there is a dj160 main jet and needle is set to middle clip