Hey, Kinda new to the ATV modification scene so excuse me if this is a dumb question but--I've got a 04 Raptor 660R that's completely stock and I plan on putting a full Looney Tuned Exhaust system on it but have no idea how to re-jet my carb. I've got friends that have done carb work but never had to deal with timing on a dual carb. Is this something a newbie can do or is it best left to a pro?

 

it is ez, i have the lte's and i had to go up 2 jets, but that is on fcr's i would say on the stockers get a cone filter or something also and go up 3-4 sizes and possibly one richer on the needle. hope this helps

 

As you increase air flow to or from your engine (your new exhaust in this case), that must be balanced out with more fuel. The stock jets may not deliver enough fuel to balance the air/fuel mixture. This is what forces you to go to bigger jets. Your exhaust manufacture should be able to recommend a jet size change. If not, you can install the exhaust, go with a stage I kit then see where you are. The stage I will have a range of jets you can try. Trial and error sucks and is time consuming. I would try to get a manufacture recommendation on your jet size, or find someone who has the same exhaust system, and see what they used.

As for actually installing the jets, that's cake. Most jet kits come with easy to follow instructions. The only real work is re-adjusting your air mixture once the new jets are in.