K&N recomends re jetting when using any of their filters on a snowmobile.Blown up Formula said:hey, i put k&n filters on my 1998 583 formula dlx. do i need to change jet size due to the potentialy higher flow of air?
actualy i would like to know this too. this is a great question, cause i put them on my 500 and ended up blowing it up. I also had a bad spark plug wire, so that might have been the cause. sometimes the plug would not fire, so when it started firing again, it would have a slight backfire, so i think that just weared at the piston and sooner or later blew her up. but i dont see why this would happen due to the filter. On any other engine, if you put a better flowing filter, it helps with performance. not saying this didnt help cause it did, but i dont think a filter could blow an engine.J_Cooke said:i heard it wasnt safe to run K&N's... i heard its risky business for the engine... is that true? what kind of advantage do u get from them?
Yes, if you didn't properly rejet after installing them. They lean the A/F ratio out so you must rejet after insatllation to make it correct, otherwise the lean condition may be enough to destroy an engine at low temps. Also, like I said I heard they fall off easy. If your sled had them on it and it was jetted on the ragged edge of lean and one fell off, then that cylinder would now be even leaner... boom.Blown up Formula said:i use them and noticed about 10mph in about a football feild. might not be exactly 100 yards, but i took off and looked down both times when i had the box and then when i had the k&n on there. My big question now is would putting k&n's help blow an engine?