I installed a Q4 alone and didn't notice much if any difference except in sound. My 09 had a big flat spot on the HP curve in the middle of the rev range. In other words it would pull, then slack off a little, then pull again when accelerating in one gear.

Then I took the bike in to have a DJ kit installed. They also took the snorkel out, and drilled out the EPA fuel/air mix plug and found that it was all the way in. They backed it out to 2.5 turns out. When I got it home, my powerbomb header had come in.

Let me take a moment to say to people without much wrenching experience that swapping the exhaust header and muffler on this bike is very, very easy and you don't need to pay a shop. I wouldn't install the jet kit myself, but the exhaust was a piece of cake.

With the mods, I can really tell a big difference. I would say it has increased the power by about 15%-20% which is a huge deal on this little bike. I can now keep up easily with traffic to about 70mph. In the dirt, there is a lot more bottom end grunt for climbing hills, etc. Also the throttle response feels a lot closer to the fuel-injected bikes I've had in the past.

All in all these were great mods and well worth the money.

 

So what does a shop charge to install the DJ kit?

 

It's pretty easy to install the jet kit too. Just follow the instructions that come with the DJ Kit. I had never done it before and it took me about an hour the first time.

 

It was 1.4 hours to pull snorkel and install dynojet - $105.00 - also because it's a new bike and I'm not a mechanic I had them go over all the critical bolts, etc.

 

TlyerSC, those few changes sure do wake the bike up. I think the jet kit also helps with the cold starting problems that some experience with this bike. Enjoy!