I just wanted to post my results as the FMF powercore4 arrived today and I put it on. In reading the package insert it said no jetting required, well I'm a couple of days away from tearing into this thing and putting on a K and N filter, pulling the snorkle, installing the dyno jet kit and going up on the pilot jet. But once I read the stuff that came with the pipe I had to put it on as I won't ride it much until I get the rest done. I had already drilled a 1/2 inch hole in the end of the stock exhaust with small but a noticable improvment so I was intersted to see what this next step would do by it's self. Once installed I fired it up and the sound was good, not as loud as I was afraid it would be but once down the road it did make some noise. As far as performance goes there was improvment everywhere. Not night and day but a noticable boost in all situations, I went for a short ride down some single track near by and was really smiling as it was a better bike off road, accelleration was quicker and with my 13 tooth front sprocket I am able to lift the front wheel now over some things with the gas alone. The bike was more snappy as it reved quicker and was quicker in the quarter mile as well. I am not going to put much time on it like it is like I said as soon as I have a free day I'm ready to do the carb so it will be done soon but I was happy with just the slip-on and am sure it will only get better from here. I'm sure I'm not the first to do this but wanted it out there for anyone who was thinking about doing this as it was worth it as far as I'm concerned.

 

You get little gains with each mod, but once you do the intake/air filter, exhaust, and jet kit, it all comes together and starts to wake this little engine up.

 

I just wanted to follow up here, tonight after work I installed the Dyno jet kit 2152 per the stage 2 instructions, I also added the kouba pilot screw f/s2 so adjustment would be easier. I didn't pull the back-fire screen yet as I was afraid the jets in the kit might not be big enough to compensate for that and a holey lid so I can do more at another time. Once done the bike fired right up and ran off the choke almost instantly, it wasn't nearly as cold natured. I couldn't ride it much as it's dark, cold and raining here right now and I didn't want to PO the neighbors as it was 9:00pm when I was done. so far it seems spot on as it runs well thru the rpms and pulled really good and it wasn't really warm for the first test. I did notice that almost all of the popping on decel was gone. So far so good as it may be a couple days before I can put any real time on it so see for sure but so far it seems better than before, I did notice improved throttle response but I didn't run the crap out of it as it wasn't all the way warmed up.