I have a full muzzy exhaust with header laying around with spark arrestor and was thinking since I'm unemployed, this would be a great time to throw it on. Can anyone recommend how to jet the stock carb on a 2009. Probably just take out the snorkle or replace it with the kdx200 one or just order a pumper carb from bill blue? Any recommendations? I know muzzy is out of business so I'm hoping someone has done this from years ago?

 

If you run with the lid on the airbox, regardless of snorkel/no snorkel, you simply get the DJ2152 kit and install as per instructions.

Running lidless requires a "special" CVK setup.

 

Do you recommend lid off? I'm Up for debate. I don't care about too loud, I do care about gas mileage. Bill said his pumper carb will get better than stock as long as you don't too crazy with the throttle. .

 

Reviewed the Muzzy full system for the KLX250S - visually, it's an impressive design !

For max power, run lidless with the DJ144 recipe (The "Full FMF System" recipe from one of the links on my signature line below..) You will need to verify that your slide lift port and slide spring are stock and unmodified - neither of which is hard to do with the knowledge in here about both...
If the Muzzy system performs well, you can expect 24 HP, top speeds of 100+mph, and better fuel economy when driven correctly for mileage.
Add the MCM (Marcelino Cam Mod) and a #40 pilot jet for max overal HP and TRQ. MCM procedure and pilot jet part numbers are in here as well.

If "less is more" for you - running with a lid on the airbox - simply use the DJ2152 kit installed as per instructions.

 

OP, I can certainly recommend the full Muzzy exhaust...been running one for many years now. Besides the obvious power increase, it is very durable in both natural use/wear and even crash survival. I can't comment on the jetting, as it's been long enough that I've had the Mikuni pumper carb to replace the OEM CV carb. As pointed out, the DJ kit is a must as far as I'm concerned when you start "uncorking" a KLX. The factory needle is the biggest issue IMO.

On the airbox and lidless function, I recommend something slightly different. IMO even the KLX300 and/or KDX200 air boot is too small once you start uncorking the KLX, especially as you increase the bore. Removing the lid obviously increases airflow, but it does bring some more intake drone and ease of water entry in extreme riding conditions...big splash and deep water crossings.

Without the lid you get more airflow than is actually require, so I kept the lid but opened up the intake opening to provide as much or more airflow as required. This did two things. It did help with the drone to some degree. With the lid still on it acts a little like an end cap on a motorcycle muffler like some designs have. The more the sound/vibration waves have the opportunity to get bounced around, the more the sound is diminished. Obviously not as diminished with the small factory opening and rubber boot, but quieter than the megaphone shape of an open airbox.

The other benefit is that even with a larger intake opening in the stock lid is that there is some benefit to shedding water. The factory box without the lid is like a large, open top, drinking cup that can act as a scoop to some degree. With the flat factory lid even with the hole enlarged, water splashed or introduced under the seat has more of a chance to run across the lid without all of it going into the airbox. A small benefit but a benefit.

 

Hey TNC whats the serial number on your Muzzy? Its on the very back of the cone. I want to make sure I have the right one before I start ripping apart my bike. Mine's a 2009.

 

The number on mine is HZ-0010. I'm thinking more of model than serial number but not sure. I see no other numbers on the muffler section.

 

mine says mz-0023. wonder if mine is from a pre 2009? what year is yours?

 

I bought the bike used from a guy I know, and the exhaust system is either '06 or '07. I would guess it even fits a KLX300 perhaps?

 

I plan on going lidless. My bike needs all the help it can get as is. I can assure you KLXter that the slide lift port and spring have no been touched. I bought the bike from the original owner and it was bone stock with 1,000 miles on it. I called dynojet today and they said they recommend stage 2 with lidless and full muzzy exhaust? But I will call them back and ask about the DJ144 recipe. I'm ..."not"... planning on doing the Marcelino cam mod or the 351 big bore. Just rejet, full Muzzy and liddles with a twin air filter. Would I still go with a #40 pilot jet? Can't wait to uncork this bike. I"m at sea level as well. Do I still drill out the plug on the recessed pilot screw and where do I place the shim on the needle? Is all this info on the dynojet instructions? Should I buy this kit directly from Dynojet? Forgive me if you've gone through this in another thread. I've been going through your posts and there's a lot. Looks like you've done your homework so I trust this will work. Hoping that throwing the Muzzy in the mix won't mess up the recipe? Thanks for you help and research.