Jetting w/ FMF Ti Powercore

For those of you who have the Powercore, how do you have your bike jetted? I've seen a few comments about it but I am looking for a definitive answer. I ride mostly 0-2500' above sea level and it will be going on an 05' WR450 with the stock header (for now). Rocky Mountain is shipping it today so hopefully I will get to try it out this weekend. Also, will the quiet core (when it finally arrives) require a change in jetting? Hopefully not so that it will be easy to change back and forth depending on where I ride. Thanks.


How about some recommendations for 6000-8000 feet on an '05 as well? I have removed AIS, YZ throttle stop, And I will be keeping the stock header. Ordering mine tonight, so hopefully Rocky Mountain won't sell out in the next few hours.

i jetted my 05 with the powercore 4 incl fmf header.

i got the jet kit from my and followed the instructions. very easy. its also a good idea to get the zip ty screw for fuel adjustment.

spec. Mj 165 needle top clip 0-2500h (special needle and jet adapter and instructions also reqd) . note that fmf jet sizes are different to off the shelf jets.

After jetting and adjusting neele clip position a few times the bike performed great and since then i got the quiet insert because i found it too loud. its perfect now and has heaps more power :thumbsup:

Thanks to "Clark4131" threads on this pipe, I bought it along with a Mega bomb header. Jetting is 170 mj, 48 pj and 1 3/4 out fuel mixture. Typical riding area is 1000 to 3500 elevation. Rode for 60 seconds and wow , what a power change. Unfortunately I didn't get to fine tune last weekend due to my son high siding on some whoops and receiving a head injury requiring a hospital stay. His bike and mine are currently at ENZO suspension for a complete rebuild and spring combo. FMF good choice :thumbsup:

Cool, sounds like I won't even need to rejet. Glad to hear you're happy with your pipe. And I hope your son is doing ok. I have a 4 year old and go back and forth about how I feel about him getting a bike in the future. In the end I'm sure he'll eventually want to do it though so why postpone the inevitable? It'd be nice if he waited until he was older though (like I did) and realized he is not invincible.


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