Jet help

[T3clay]

Hey everyone I have a quick question, how do I know what size jet I need I have an 11 hp HF predator that has a strait header and new air filter, I have been told I will need to rejet. This is a little beyond my knowledge.

Thanks for the help an I hope this isn't a stupid question!

 

[jeeperjoel]

take out the jet from carb, it has a number on it, then get a few jets the next sizes up, it's kinda trial and error, go up one size at a time checking spark plug readings and taking test runs

 

[T3clay]

0570 is the size I have so am I looking for 0571? 0575?

 

[T3clay]

Seems that 05703 Ida popular size for gx390 but I can't seem to ind any doing a google search

 

[OzFab]

As Joel said, all you can do is try it...

 

[T3clay]

Scan anyone recomend a good supplier?