Got my Muzzy slipon in on friday, but I worked 16 hrs a day on friday and saturday trying to get the race bike ready to roll. I wuz a bit tired this morning, but the change from working on the race bike to working on the KLX was welcome.
I purchased the KLX 300R slipon (w/optional quiet core) direct from Muzzy, and purchased a slightly used stock KLX 300R headpipe on Ebay, both arrived on friday.
The install took all of 45 minutes, but was quite unique. First....I didn't get the pipe clamp or gasket with the headpipe, so I improvised with a Harley pipe clamp and some high temp header wrap for the gasket. The HD clamp didn't quite make the pipe connection bulldog tight, but there are no leaks. I fired the bike up without the quiet core insert, and it was a bit too loud for my taste, so I installed the quiet core insert and screen....not a heck of alot of difference sound wise.
The only other modification was to the inner part of the snorkle in the breather box. I cut the guts out of the rearward side of the inner snorkle, which ain't really gonna do much, and I installed a high-flow Moose filter element (high-flow being questionable). I only rode the bike lightly till she got warm, but enough to see if the simple mods had caused any popping, backfires, or carb coughs...none were evident. A new plug after warmup didn't show any signs of being too lean, but I won't be sure till I do further tests and experiment with intake air flow. It's still a bit loud, but should quietdown a bit after use (as per Muzzy).
Everything went together as it should, but I will be ordering the correct pipe clamp and gasket. I'm quite satisfied with the quality and fit of the Muzzy parts, and the weight savings were substantial. The 250 heat shield fit perfectly on the KLX 300 headpipe, and the headpipe bolted up perfectly to the 250 head. There's not a huge difference in the diameter of the headpipes (250 VS 300) but every little bit helps, and this method saved me almost $200 over the full Muzzy system. Total cost....$304.95 (free shipping).

 

Saving money.......priceless. Nice.

 

You added a muzzy slip on, 300 head pipe, and an aftermarket airfilter... and you didnt say you jetted it? This contradicts what ive been hearing since it should come already lean from the factory and those mods should lean it even more? Im so confused[&:]

 

Don't be confused bro. As I stated in the original post, the plug showed no signs of being too lean initially. Bear in mind that I have not done a true plug chop yet...I simply checked the "new" plug after riding it gently. The plug condition after a gentle ride doesn't tell me alot just yet, and I'm at an altitude of roughly 2400', so please don't judge my conclusions just yet....and unless you're living right next to me, and have done identical mods...the final conclusions won't mean diddly for you.
I did just walk in from a spirited ride combining dirt and street, and I can feel about what I expected to feel, mods VS stock. Well worth the price paid, and these are mildmods thus far.
Muzzy slipon
14/47 sprockets
Airbox mods are not really worth mentioning.
Rips fairly well thru 4th gear (MUCH better than stock...but more mods will do better)...5th and 6th are so-so at best, but better than stock.
Slight popping on deceleration (jetting will be required).
Still won't hang with the similarly modified 300R....but it's getting there.
1st gear wheel pops with throttle only (I weigh 155# on the seat back)....no 2nd gear pops without some clutch...no 3rd gear pops without help from the terrain, 4th gear pops are out of the question!
{Disclaimer; Your results from similar mods will vary due to YOUR altitude, YOUR ability, YOUR jetting, YOUR weather....and a host of other variables! This is a real life test, nothing to prove to anybody, YMMV. Please do not base my results on your wallet. Just have fun with your bike...that's all that matters! I'd ride with you if you had1/10th the HP....it's all fun...don't take the fun out of it by getting too worried about who has what. Got a 5hp Briggs?...call me, and we'll ride!...a grin is a grin...doesn't matter if 5hp produced it, or 300hp produced it!}

 

Kawasakifan700...please don't take my post as being too harsh. I've been messing with bikes long enough to know not take anyone's word for anything. I put a set of cams in a1200 Sportster a few years ago, and jetted the carb the way I was "told" to (190 main)...the bike ran like a bear till it hit 5000rpm then fell on it's face. I put it on a dyno, and walked away with a 160 main (stock was 170) and it screamed! It never showed any signs of burning a piston, but that jet was unheard of in a Sportster with those cams...it worked though! Baseline jetting info is fine from these online groups, but ya gotta jet for your bike, for your area, according to your modifications.Stay a tadon the rich side VS lean if you don't have a dyno nearby and you'll be fine.

 

Hey Snal did you run the muzzy minus the quiet core at all. I just got the muzzy on minus the quiet core and it is Damn loud. I was wondering if the core really helped alot or not. It certainly made a difference on the power though. I haven't done the air box mods yet but I am presently ripping it apart now. Happy wrenching!! Jeremy

 

I'm following just this advice. I'm at roughly 2400 myself. Full Muzzy #125 main (NITC) needle at 2 clip fuel screw out 2.5 turns ect ect. I'm a bit rich for sure.

I cant believe your bike runs good without jetting, but it does. Sweet, let us know where u end up.

 

I have full muzzy #132 main with n1tc needle on 2nd clip #40 pilot jet and the a-f screw at about 2.25 turns at about 700 ft elevation. These are the same as cwgoffs since we are around the same elevation. I ran it with the airbox lid on and liked it. But I thought it started to break up around 7g . I just took off the airbox lid and tried it. Holy sh#t what a difference. It pulled hard all the way thru the gears with no break up at all. I also have 13-45 gearing. I wonder if I can keep the lid off and run a good filter with maybe a outerwear cover and keep the dirt out off the motor. I still want to do martys pcv mod also along with no brakes crank mod. This bike is starting to wake up.

 

Nothing harsh taken . I just didnt know it was possible, but im glad i do know. You got any pics of the new mods?