maybe another 09 owner can verify about the cap on the a/f screw.... I doubt that if the diaphram was drilled to a klx300 spec that it would screw stuff up... hell thats what pretty much everyone has bought pre the 09 kit is the klx300 kit. Maybe someone has been in there foolin around already.

 

Yeah, when I get it out next I'll take a closer look. I'll take a drill bit and see if it's the bigger size of the 300 kit or not. Which size is that again?

 

i believe its 7/64"

 

Wait a minute. You have a full Muzzy, twin air, airbox lid off and are running a STOCK 118 main jet? DJ kit jets do not start with "K" they just have a number stamped on them. That doesn't seem right to me, also where is the needle set? What does your plug look like, my guess, you are way way lean, especialy at 3/4 to WOT which is exactly the area you are saying is the problem, wot, slowly building power, highway, etc.

I say, pull the carb, get a new jet kit and re do what ever the PO did before.

 

People. Reading comprehension. In the first sentence I say I'm running a 128 dynojet main and I pulled a K118 out. The needle is set per the dynojet instructions, 3rd from the top.

I might add the "no power" aspect falls way below even stock power. Though that might be apparent since I can barely top out at 55mph.

 

and as far as having to drill the plug out for the a/f screw,, I had to with mine. the screw was covered with an aluminum plug,, so deff very strange,, someone has been in your carb and like the above post I would make sure you get the proper jet thrown in..

 

Sorry, I guess I am just a stupid dick trying to help. Good luck, my bike runs fine.

 

Um, I'm thinking like ^^ that you may be running lean. I'm running a 128 main jet, about 2.5 turns out on the screw, and stock pilot with the only mod being that I pulled the snorkel out of the airbox. With a full exhaust and an aftermarket filter AND being at relatively low EAS, I'd *guess* you need a 132 main jet, and to raise the needle up a clip. I think if it starts and idles ok you would be able to stick with the stock pilot.

 

a bit harsh on the "reading comprehension" comment. they're just trying to help. anyways, listen to NB, Tremor, and what EMS said. They know what they're talking about.
I know a little. On my '09, I installed a 300 Muzzy full and a 300 DJ kit. I live at 1000 feet asl. I used a 128 main, left the stock pilot. The stock pilot will work 99% of the time and anyone who changes it is really just wasting time. That's why we adjust the fuel screw. My '09's fuel screw was covered up just like my '06's was. It required drilling it out to get to the screw just like everyone elses. Someone indeed has been in your carb.
Listen up, when I FIRST put in my needle on my '09 (remember, it's the DJ whereas my '06 had Keihin parts) it would run like a bat out of hell up to highway speeds then it would sputter and then would die if any gas was given. I limped back home and ripped the top of the carb open and took the diaphragm and needle out and reinstalled them. It fixed it. That thin rubber material that sits on top of the carb is fragile and has to be installed very meticulously. Like Tremor said, make sure each edge is seated perfectly in the groove. And make sure your needle is sitting straight up and down. You can verify this better if you're holding the carb in your hand and looking through the inlet side to see the bottom of the needle. Do that, set your fuel screw somewhere between 2.25 and 2.5 and if you're at the 3rd notch, try the 2nd notch. It sounds like it isn't getting enough gas at higher rpms. Again, I don't think it's your main jet or your pilot as the DJ main is even larger than the Keihin but not by much. This is just my thoughts and it may not work but try the easy stuff before having to rip in the bottom of the carb. Also, this is important- make sure the boots up to the carbs are PERFECTLY lined up and the clamps tightened very securely. Any air leaks are not your friend. Also, don't overoil your air filter.
Removing the smog system won't add performance but will free up space under the tank and make it look neater and also reduce the temp of your exhaust gases. The crankcase vent will make it rev a smidge quicker but really I don't know if it's that important. If you do do it, just burn your way through with a red hot drill bit. It's a lot quicker than drilling manually and there's no shaving mess. You'll have to remove your header either way you do it.

 

maybe someone knew enough to try to adjust the a/f screw but didnt want the hassle of tearing into the carb. thats why the a/f cap was gone... Did you buy this bike "new"? if so, id be going back to the dealer ready to tear into someone....