Is an exhaust worth getting for a 09 Yz450f?

Hey guys I just got a new yz450f 09 and so far I did the print mod and what a difference it makes.

Now I dented my header on my bike from a dumb log and im looking to yet an exhaust.

Well I was looking at drd, fmf, and yoshi. Well here's the thing, my buddy who has a yz250f says I won't notice no bottom end from putting an exhaust system on my bike.

He told told me to re degree my cams and stuff but I just want to keep the bike stock and reliable. But I ride woods and I'm going to be racing harescrambles, and I need more low end snap and more mid range. The top is good but I mainly need more low and mid.

Now I was mainly looking at the fmf 4.1 and mega bomb stainless because eleven ten mods told me they can get the system shipped to my house for $475.

But what about the other pipes? How do they work for you? And what do you recomend? Also will I notice a little or big difference in low end? Also I know I'm going to have to rejet but hey that's all apart of the fun!

Thanks guys and sorry for making another thread, I looked around tons and tons of pages and I couldn't really find what I was looking for.

God bless!

Alex

YES!!! 08-09 450's benefit greatly from an A/M system. A full system offers the best gains, but even just a slip-on is a great improvement in the mid-range. While your buddy may be correct in most examples, the 08-09 oversized header/baffled muffler is an anomoly that any aftermarket system will improve upon.

Do it.

Don't listen to your bud and start playing with cams. A good pipe will make it feel like a different machine.

my buddy who has a yz250f says I won't notice no bottom end from putting an exhaust system on my bike.

You buddy obviously isn't familiar with the '08/'09 yz450f exhaust systems and how restrictive they are. I've owned 9 mx bikes, and 8 sport bikes - road-raced and race MX as well. Of all the bikes I've owned, my '09 yz450f has been in the top 3 as far as an aftermarket system making a HUGE improvement in power.

As far as what to go with, if you want more bottom end I'd go with a Dr.D but really... any system you put on will make a BIG difference ! I've got an FMF mega-bomb header paired with a Pro-Circuit T-4 slip on, it's got way more bottom/mid than i had stock. In fact, I bought another complete PC system for my bike in case I damage this one, I hate the stock pipe and I don't want to ever put it back on the bike.

What is a "print mod?"

On your 09' just like mine, you'll notice big gains everywhere from a exhaust change. I'm running a megabomb with a PMB insert open.

It's not a psychological gain on this bike, shit gets real.

I put a Dr. D pipe on my 09 yz. Big improvement. Do yourself a favor and buy an 06 yz cdi off eBay and a Rekluse Pro also. After these mods you will put the yz in tops of all bikes you have ever owned.

Somebody tell me about the "print mod" I have an 08 but ride my 07 CRF450 because my YZ is lacking

Somebody tell me about the "print mod" I have an 08 but ride my 07 CRF450 because my YZ is lacking

Don't know what the print mod is. Just read my post and take some good advise. After those mods you will have the near perfect motor performance. Good solid power everywhere.

i'd just buy a 06 exhaust system on ebay personally. it'd be about $150. then just spend the extra $325 on practice/racing fees and tires.

WOW!!! They really add that much more power? Now is the fmf 4.1 with the megabomb any good? But it is like a night and day difference?

Also now what would the 06 cdi do? Will it give my bike more low end hit? ALso I thought the plugs were different?

Any other exhausts i should look at? Also how is the jetting like too?

WOW!!! They really add that much more power? Now is the fmf 4.1 with the megabomb any good? But it is like a night and day difference?

Also now what would the 06 cdi do? Will it give my bike more low end hit? ALso I thought the plugs were different?

It's not that the aftermarket exhaust systems add that much more power, it's that the stock system robs so much. The stocker is a horrible pipe if you like any sort of bottom/mid hit.

YES, IT IS A NIGHT AND DAY DIFFERENCE. :thumbsup:

The 4.1 is a good pipe, really they all are in comparison to the stock junker. Have I mentioned that I don't like the stock pipe ?

Yes, the '06 CDI will give you even more bottom end hit. They were selling pretty cheap on E-bay a while back ($25), the electrical connections are the same from '06 to '09. I have a CDI from an '06 on my '09 as well.

3 things you'll want to do :

#1) Put a full exhaust system on

#2) Put a bigger main jet in, and raise your needle by 1 or 2 positions

#3) Install a CDI from an '06

You will be more than happy. :thumbsup:

WOW!!! They really add that much more power? Now is the fmf 4.1 with the megabomb any good? But it is like a night and day difference?

Also now what would the 06 cdi do? Will it give my bike more low end hit? ALso I thought the plugs were different?

Any other exhausts i should look at? Also how is the jetting like too?

I like the Dr.D. Gives good low mid improvement. Yes you will gain up to 6 hp from an aftermarket pipe. A cheaper way is to put a stock 06 yz pipe on though. Do a search on the 06 yz cdi. Many of us have done it. It just gives an extra low end punch which works well with an aftermarket pipe. Like I said I feel it be nearly perfect power. The 06 cdi is a two minute direct swap.

Here in Northern California we all run a 48 pilot, 1 richer clip on the needle and a 165 or 168 main.

It's not that the aftermarket exhaust systems add that much more power, it's that the stock system robs so much. The stocker is a horrible pipe if you like any sort of bottom/mid hit.

YES, IT IS A NIGHT AND DAY DIFFERENCE. :thumbsup:

The 4.1 is a good pipe, really they all are in comparison to the stock junker. Have I mentioned that I don't like the stock pipe ?

Yes, the '06 CDI will give you even more bottom end hit. They were selling pretty cheap on E-bay a while back ($25), the electrical connections are the same from '06 to '09. I have a CDI from an '06 on my '09 as well.

3 things you'll want to do :

#1) Put a full exhaust system on

#2) Put a bigger main jet in, and raise your needle by 1 or 2 positions

#3) Install a CDI from an '06

You will be more than happy. :thumbsup:

AWESOME!!!!

Now does the 06 cdi like mess with the bikes reliability at all? Im new to the race four strokes so cut me some slack hahahahaha.

I also heard about the cams, but im not sure right now for those. What exhaust do you run?

I like the Dr.D. Gives good low mid improvement. Yes you will gain up to 6 hp from an aftermarket pipe. A cheaper way is to put a stock 06 yz pipe on though. Do a search on the 06 yz cdi. Many of us have done it. It just gives an extra low end punch which works well with an aftermarket pipe. Like I said I feel it be nearly perfect power. The 06 cdi is a two minute direct swap.

Here in Northern California we all run a 48 pilot, 1 richer clip on the needle and a 165 or 168 main.

WOW i cant belive yamaha would throw that pipe on this bike. Now im here in PA i think like 1500ft or something, should i leave jetting stock then go from there?

Also did you notice even more bottom with your exhaust system? By adding the cdi?

Also did you notice even more bottom with your exhaust system? By adding the cdi?

Really? Are you reading any of the posts?

Really? Are you reading any of the posts?

:thumbsup::thumbsup::lol: i run the stock header with a fmf powercore 4. this is the best combo i think that there is also vary inexpensive. i felt the best gains through out the entire spread. i had a DRD full system was vary nice but the header dents vary easy and gets super annoying to have to loosen i every oil change. Also had a mega bomb header and 4.1 can was also go but did not notice any thing differnt, from what i have now. the header is not the problem in the 08-09 its the silencer. also i would recomend doing the Oring mod and getting your jetting spot on.

:thumbsup:

:cheers::smirk::lol: i run the stock header with a fmf powercore 4. this is the best combo i think that there is also vary inexpensive. i felt the best gains through out the entire spread. i had a DRD full system was vary nice but the header dents vary easy and gets super annoying to have to loosen i every oil change. Also had a mega bomb header and 4.1 can was also go but did not notice any thing differnt, from what i have now. the header is not the problem in the 08-09 its the silencer. also i would recomend doing the Oring mod and getting your jetting spot on.

One of the last things I would do is the oring mod. Can't believe anyone would do such a hack mod. Do you think Bubba had this done on his 450 last year? Don't think so.:bonk::thumbsup:

:thumbsup:

One of the last things I would do is the oring mod. Can't believe anyone would do such a hack mod. Do you think Bubba had this done on his 450 last year? Don't think so.:cheers::thumbsup:

no he had a EFI:banghead: last year. it is a vary good mod. you can also spend 30 from Tokyo mod for the same thing. it just a stiffer accelerator pump spring

Really? Are you reading any of the posts?

Sorry man!!! hahaha my bad

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