More snap please

could always bump up compression but i don't really like that because you are stuck with 110 for the rest of the life of the piston

There are at least 3 different stainless steel full systems available for around $400 that will out perform your modified system in terms of higher power through the mid range, better throttle response (the "snap" you are after), and noise reduction. The fact is that the OEM exhaust on the '08-'09's is a poor system with a badly designed muffler and an oversized header, and relieving the muffler, even though it does improve it, will not make it match the performance of a system that's right for the engine.

You could swap in an '03 motor :thumbsup::smirk:

My '03 with the head reworked by Dave at MX Time will rip your arms out of their sockets. Very close to the feel of a big smoker.

... Very close to the feel of a big smoker.

...and a lot more thrilling than it is useful. In fact, not only is the '03 difficult to ride because of its very abrupt nature, it's actually not as powerful or as quick as the "mellower" '06 model. (I owned both at the same time, and I can tell you for a fact that this is true).

Besides, the engine wouldn't fit directly, and all you would need for the same effect is the '03-'05 cams and a different CDI.

Gray, which systems are under $400. I've heard Dr. D isnt too pricey. Do they weigh much more than stock? SS header vs Ti.

The DRD is about the same weight as stock. The header is heavier, while the muffler is lighter, so the weight moves down and toward the middle.

MRD is around $400, as are some of the Yoshimura systems.

What is MRD? I checked Yoshi's website quick and the cheapest system i found was $595. I'm in a rush but i'll look around to see if i can find it cheaper somewhere else later tonight. Thanks again for all the help you've given me :thumbsup:

I have an '07 and put in the '06 CDI and noticed a definite difference in the low to mid, it should be even more noticeable in your '08. My buddy has an '08 and I know how much more mellow the bottom end comes on with it compared to mine. I can't say exactly how much difference the Hot Cams will make on an '08 but they're not $700 as someone said earlier, more like $250-275.

I think the cheapest and easiest is to try the '06 CDI first and see what you think; I'm sure you'll find it a big improvement. If it's not as much of an improvement as you're looking for, then move on to the next additional thing.

...and a lot more thrilling than it is useful. In fact, not only is the '03 difficult to ride because of its very abrupt nature, it's actually not as powerful or as quick as the "mellower" '06 model. (I owned both at the same time, and I can tell you for a fact that this is true).

Besides, the engine wouldn't fit directly, and all you would need for the same effect is the '03-'05 cams and a different CDI.

My comment was made in jest, hence the :thumbsup::smirk:

For my situation, my '03 is perfect. :bonk:

I agree with rbinstoon. I have an 06 and I bought some parts off a blown 08. Included with all my junk parts was the 08 CDI box. For kicks and giggles I put the 08 box on the 06 and hated it. It made that much difference on the bottom and mid power. Replacing the CDI with the 06 would be the cheapest power improvement you could do. I suggest hitting e-bay for a used 06 box.

Pick up a pipe system later when you got some cash burning a hole in your pocket.

Thanks for the input guys. I'm gonna get a 51 rear sprocket and 12 front, then an '06 cdi. Ive got birthday money coming my way in a few days.

The '06 cdi is a little less aggressive on top end than the '08 right? Either way, it isnt a problem as i tend to rid in the low and mid rpm range most of the time.

I personally think the 12T would take away too much off the top...Maybe just do 52T rear...

IMO, the best advice here is the 06 CDI, ZipTy carb mod (after I had this done, my friends say it made the bike feel like it had EFI), Hot Cams, and exhaust (I've tried DRD, FMF, and White Bros, and the White Bros definitely had the most bottom end punch but was loud as hell, so I stuck with the FMF Q4)...These things will definitely give you a low end punch, without sacrificing much (if anything) on top...

I personally think the 12T would take away too much off the top...Maybe just do 52T rear...

I'm not concerened about top end speed too much. Can you use a 52 tooth without modifying the stock chain guide? I thought 51 was the biggest you could go with no modifications?

Hmmm, sorry man, you may be right...I only run a 50 so I'm not sure on that...Are you just trying to make a wheelie machine? Because you can easily get to the point where that bottom end hit actually slows you down due to wheel spin, then you'll be like, "damn, now I've got to throw a flywheel weight on"...But if you're just looking for that instant throttle response, I'd say the ZipTy carb mod is the best bang for your buck...

Hmmm, sorry man, you may be right...I only run a 50 so I'm not sure on that...Are you just trying to make a wheelie machine? Because you can easily get to the point where that bottom end hit actually slows you down due to wheel spin, then you'll be like, "damn, now I've got to throw a flywheel weight on"...But if you're just looking for that instant throttle response, I'd say the ZipTy carb mod is the best bang for your buck...

I'm just looking for a bit more to make it like a 2t. More like the instant snap, but not enough to make it worthy of me buying a 2t. I love the broad power band of a 4tand i've always had a 4t other than 2 bikes.. I'm not looking for a 'wheelie machine' exactly, but i like the instant throttle response and how easy it is to get the front wheel over a log in a sketchy situation. I've already got the heavy GYTR flywheel. I wanna replace both my sprockets anyways seeing as i just bought a $140 chain and i want this thing to last. What exactly does the ZipTy carb mod help with? Throttle response? What is the turn-around time right now?

Sorry if im not making sense, it's 6:45am here. Anyways, thanks for all the help guys.

Edited by ttr250dude
I'm not concerened about top end speed too much. Can you use a 52 tooth without modifying the stock chain guide? I thought 51 was the biggest you could go with no modifications?

got a 52 on mine with no problems, and no mods.

You WILL NEVER get the 450 to "Snap" like a 2t, period. You have a stock pipe, and won't change it, now you say it's got a flywheel!! well that was the wrong way to go for wanting "Snap." Sorry Dude, but it's like,,, "Quit wasting out time."

That 12 tooth sprocket will shorten the life of that $140 dollar chain. You also need to consider that the smaller sprocket will eat the swing arm chain guard and you should really use a 12 tooth case saver. Just some things to consider before you try it.

I really do not know what your looking for. I run a 13/50 and make all the power needed for MX or a joy ride threw the trees. Mite I also add that I have two 250 two strokes sitting in the shop that get rode every time we go ride.

Some of post above are very true, you can change things around to the point that the bike makes less power and will handle like crap. That will just frustrate you and make the bike less enjoyable to ride.

Leave the bike as it is and save your money for tires, chain and sprockets, safety gear and have money for when you break something. Just my 2 cents, I have nothing more constructive to add to the thread.

I agree with the above, a 12T sproket will eat your chain sooner. If you wanted more snap you went the wrong direction with the flywheel weight.

I'm just looking for a bit more to make it like a 2t. I've already got the heavy GYTR flywheel.

Man, I'm sure we're all starting to slap our foreheads at your posts now...The flywheel weight is specifically made for reducing that initial abrupt hit...I've owned many two strokes and have been riding since I was 12 (I'm almost 40 now)...My 07 YZ450 is my first 4t...I've had a couple yz125's, cr250's, yz250's, and a kx250...This 4t easily has more bottom end torque and hit than any of them...As far as lifting the wheel easily to get over a log, are you serious? I'm 6'3" and 200lbs and can lift the wheel easily at any time from 1st-3rd gear...I can't even let a beginner ride my bike because if they hit a bump and grab even a little too much throttle they'll loop it...All of my 2t's had more of a feeling of taking off like a rocket in the midrange of the power band, and liked to be ridden with more of a wide open throttle style (which would easily loop me out or make me crash on the 450)...

So if you really want what we think you're looking for, you'll have to remove the flywheel weight, use an 06 CDI, consider the ZipTy mod (yes it does improve throttle response), and start saving some dough and get a full exhaust system...Even though I've settled with the FMF Q4 (for the stealth factor), I think the best way to go is the DRD simply because you can use the radiator lowering kit with it (to this day the best track handling bike I've ridden was a friends 07 YZ450 with the lowering kit, granted he did have some money in the suspension also)...

If after doing these things, it still doesn't do it for you, then start looking into motor mods (Hot Cams, ported head, and such)...

Side note: any bike I've ridden with extreme gearing (granted the few were streetbikes) is just straight up lame, and I throw those into the same category as a tricked out bling quad with a super stretched swingarm...Just ruins the usefulness of the bike for real riding...Don't go down that path...

If you don't like the advice already given by myself and others on this thread, there's really not much more anyone can add except "Go buy a used KX500"...But remember straight HP does not equal speed on the track or trail, there is big difference between power and usable power...

Sorry if im not making sense, it's 6:45am here and i still havent gotten to bed and I just got back from a party

Kids:bonk::thumbsup:

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