[Dauntay]

I got a 2008 yfz 450 and my exhaust pipe gets really red and hot. Also likes to back fire after I let off the gas and after I shut it off. I’m thinking it needs rejetting. Any recommendations on size of jetting? 500’ elevation.
TIA

 

[hew]

what mods do you have? And what jets are in it rn?

 

[Dauntay]

what mods do you have? And what jets are in it rn?

I don’t know what mods are on it. Pretty sure it’s just an exhaust. I bought from a guy and it’s been sitting for 3 years. I’ll look at the jets and get back to you

 

[Dauntay]

what mods do you have? And what jets are in it rn?

I have a 48 pilot and a 170 main

 

[hew]

try to adjust the fuel screw and if it doesnt work or it doesnt backfire when the screw is 4 turns out or more bump up the pilot to a 50

 

[hew]

Also check all the carb boots and make sure their tight and the exhaust gasket. And are you running a fan? If so does it come on after a bit of it the quad idling?

 

[hew]

try to adjust the fuel screw and if it doesnt work or it doesnt backfire when the screw is 4 turns out or more bump up the pilot to a 50

try to adjust the fuel screw and if it doesnt work or it doesnt backfire when the screw is 4 turns out more bump up the pilot to a 50*

 

[Dauntay]

try to adjust the fuel screw and if it doesnt work or it doesnt backfire when the screw is 4 turns out more bump up the pilot to a 50*

I do have and fan and it doesn’t come on when idling. And I adjusted the mixture screw and seems to be ok

 

[hew]

does it still backfire since you adjusted it?

 

[hew]

I do have and fan and it doesn’t come on when idling. And I adjusted the mixture screw and seems to be ok

You should look at this forum on how to check the fan. Checking Cooling Fan

 

[Dauntay]

It doesn’t backfire anymore but it won’t idle at all.

 

[hew]

have you tryed adjusting the idle?