09' yz450f yoshi

What do you guys think about this pipe on this bike? Its a c96 yoshi slip on. And its going on my 09 yz450f. will it sound any different (better) and will there be any power gains? and what about the jetting.

you will see power gains with almost any after market exhaust on a 08-09 yz450. But if you want to get the most bang for your buck you need to get a full system. The stock silencer is very restrictive, so they made the header large to compensate for it. Thus the stock header is not ideal with a slip on. The bike may sound louder, but not really different it is a 450f and imo they all sound pretty much the same, "better" is all opinion. As far as jetting goes, it all depends on temp, altitude etc. I as well as many others had success switching to a 165 main, 4th position on the needle and some messing around with the fuel screw. Try checking out the jetting data base if you want more info.

This and the glowing header question have been beat to death on here, I vote for a sticky on 08-09 exhausts if there isn't one already.

you will see power gains with almost any after market exhaust on a 08-09 yz450. But if you want to get the most bang for your buck you need to get a full system. The stock silencer is very restrictive, so they made the header large to compensate for it. Thus the stock header is not ideal with a slip on.

Hey S,

X2 on what Steel Panther said, I put a FMF megabomb header with a Pro Circuit can/muffler on my '09. I raised my needle by 1 position and I put a bigger main jet in as well. Yoshimura makes good stuff, they're one of my favorites & I think the sound from something like that would be a definite improvement.

Did you end up putting new valve seals in your bike ? I remember you talking about that.

I don't even see the point of putting a pipe or jets on your bike. I have a 2009 yz450f and the power is pretty insane. I can't imagine it with more power... probably wheelie the bike a lot easier? I wouldn't want that lol. If you're getting it for sound... eh I don't know if that's worth it ha

I don't even see the point of putting a pipe or jets on your bike. I have a 2009 yz450f and the power is pretty insane. I can't imagine it with more power... probably wheelie the bike a lot easier? I wouldn't want that lol. If you're getting it for sound... eh I don't know if that's worth it ha

The power with the stock pipe is very mellow. Probably good if you're a trail rider but it needs a pipe for racing MX.

I don't even see the point of putting a pipe or jets on your bike. I have a 2009 yz450f and the power is pretty insane. I can't imagine it with more power...

I run B or Intermediate and I HATE the stock pipe, in fact I bought 2 new complete systems just so I've got one as a back-up. I can guarantee you that I will never ride my '09 with the stock pipe again, ever. I had a full Pro Circuit system on it from new, then bent the PC header so I put the stock system on for a week, during that week I ran a race and a couple days of practice.

I was used to the power/delivery with the PC system on, knew when to get on/off the throttle to hit one jump in particular - A 105' - 110' uphill. I ended up thinking I was at the right speed, throttle position and found out I wasn't. Came up short a couple times, then over compensated for the "mellow" (crap IMO) power. Ended up over jumping that uphill, had my left hand come off the bar and my chest hit my bar pad resulting in a month of missed riding due to an injured wrist - I still have trouble bench pressing almost anything when working out, the angle you've got to have your wrist at dosn't work anymore.

There's a reason why I had read that one of the first mods to do was to put on an aftermarket pipe, you don't see many '08-'09 yz450f's with the stock systems still on & there's a reason for that - they suck !!

Here's a pic of the jump I was talking about :

DSC_0028.jpg

a LEXX end cap on the stk muffler will wake up that 08-09 YZ450F. and if u dare to venture further into that stk muffler, remove the inner cone then reassemble.

i feel for the small amount of time invested in this mod and the LEXX end cap is better than any aftermarket exhuast out there

Put a full Yoshi exhaust on my 08 and could not imagine going back to stock! Major "snap" of the throttle and it really opens up the bike! Google it and you will find great deals from small vendors; I think I paid around $400 for me complete stainless Yoshi. The one thing I would do after getting the pipe is take off the stickers before the heat gets to them. You will end up doing that anyway after a few months.

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