2007 Yz450f

[YZ450FORD]

Hey i am new at this site and i am fairly new to dirt bikes i grew up learning how to ride on my banshee, and i wanted to jump on the four stroke dirt bike train.

My bike i nearly stoke all i have is new renthal 49 tooth sprocket, new o-ring chain, and asv leavers, i want to now work on the engine. My friend has an 06 250F who thinks he can keep up with me. His bike is stock louder than mine, whats a really good slip on thats not only loud but better performing than stock?

I hear a lot about not even changing the bike because it is already well set stock, is this true? Also what about jetting the bike, is it worth it? The bike will be mostly ridden in Glamis and in the summer the track. What do you guys think?

THANX MIKE

[642MX]

Welcome to TT. There is a post stickied at the top of the forum page with answers to FAQ. And remember that less noise equals more places to ride. ?

[Slinkyman16]

welcome to the board..

as far as the bike is concerned.. it is true that the bike is already pretty massaged in the power department.. a aftermarket slip on really wont do much to the bikes power but will move the power up or down depending on the pipe.. if your going to change the exhaust i reccomend a full system it is a bit costly but will be a better benifit to the bike.. you should get the bike jetted for the altittude your riding.. it will help the bike out so much.

i hope this helps. but you will find lots of information on this site.. just look around and you will find all the answers to your questions.

[Ranger18]

Jetting... try a 45/165 for current temps.

Loud exhaust.... suck. so do slip on's. Go to www.mrd-racing.com

If you don't want to go that route try a dr. d or WB full system

A rider on a 250f can keep up with a rider on a 450f, especially on a track. RV's lap times on a 250 are only 2-3 seconds behind Bubba's, which means that RV can spank just about any other 450 rider out there.

So the real question is, is your friend a better rider than you?

One last thing, I would have gone with a 50 tooth rear sproket, especially if you primary riding spots arre glamis and tracks.

For galmis I would flush the cooling system and use engine ice. It might not be a bad idea to get a boyesn water pump to help the cooling. I'm not saying that you need it, but if you spend a lot of time at glamis, your bike will love you for it.

[grayracer513]

I think your strategy for beating your friend by making your bike louder is doomed to failure, for one thing, and demonstrates not only a misunderstanding of the exhaust system's relationship to engine performance, but also a pronounced lack of respect for those near where you ride.

You asked.

[runester]

I think your strategy for beating your friend by making your bike louder is doomed to failure, for one thing, and demonstrates not only a misunderstanding of the exhaust system's relationship to engine performance, but also a pronounced lack of respect for those near where you ride.

You asked.

Ditto...?

[Climber]

I think your strategy for beating your friend by making your bike louder is doomed to failure, for one thing, and demonstrates not only a misunderstanding of the exhaust system's relationship to engine performance, but also a pronounced lack of respect for those near where you ride.

You asked.

But would make a really good plot for a episode on the Simpsons.

[Polar_Bus]

I think your strategy for beating your friend by making your bike louder is doomed to failure, for one thing, and demonstrates not only a misunderstanding of the exhaust system's relationship to engine performance, but also a pronounced lack of respect for those near where you ride.

You asked.

Way to go!, keep the mis-informed new guys educated on riding SILENT to save our trails.......

Isn't it funny how the kids that cry the loudest about "no places left to ride" also have the loudest, most obnoxious race exhaust on their bikes, and don't even race?

[grayracer513]

(That) would make a really good plot for a episode on the Simpsons.

I'm not as gung-ho on striving for the absolute quietest exhaust you can have as some here are, although in some circumstances, it really is called for. But, to go looking for a new system deliberately to make the bike louder is just plain stupid.

[nap__kxf]

Jetting... try a 45/165 for current temps.

Loud exhaust.... suck. so do slip on's. Go to www.mrd-racing.com

If you don't want to go that route try a dr. d or WB full system

A rider on a 250f can keep up with a rider on a 450f, especially on a track. RV's lap times on a 250 are only 2-3 seconds behind Bubba's, which means that RV can spank just about any other 450 rider out there.

So the real question is, is your friend a better rider than you?

One last thing, I would have gone with a 50 tooth rear sproket, especially if you primary riding spots arre glamis and tracks.

For galmis I would flush the cooling system and use engine ice. It might not be a bad idea to get a boyesn water pump to help the cooling. I'm not saying that you need it, but if you spend a lot of time at glamis, your bike will love you for it.

woah woah woah. now i know you couldn't be comparing rv's factory kx250f and bubba's factory kx450f to YZ450FORD's 450 and his friend's 250f. comparing a factory bike to a stock bike just won't work, those factory bikes are nothing like their stock counterparts. if you put the same rider on a 450 on a track, he'll be able to go alot faster than if he was on a 250f, that is if he could actually use the power from a 450. and using rv as an example for that is silly anyways, the kid is one of the best riders in the world, not a good comparison for YZ450FORD.

[grayracer513]

woah woah woah. now i know you couldn't be comparing rv's factory kx250f and bubba's factory kx450f to YZ450FORD's 450 and his friend's 250f. comparing a factory bike to a stock bike just won't work, those factory bikes are nothing like their stock counterparts. if you put the same rider on a 450 on a track, he'll be able to go alot faster than if he was on a 250f, that is if he could actually use the power from a 450. and using rv as an example for that is silly anyways, the kid is one of the best riders in the world, not a good comparison for YZ450FORD.

First, he isn't comparing a factory bike to a stocker, he's comparing two riders of reasonably similar skills on bikes of the same caliber in two different displacement categories. The same two, in fact, in question here.

Second, there are tracks where the 250f's are faster than 450's. You know that Doug Dubach ran several top ten and podium finishes in 250 (450) pro races on the YZ250F prototype in 1999 and 2000? They took the stickers off, and everyone though it was a 400. One year, Bubba posted teh fast time of the day at Daytona on a KX125.

My son is not one of the best riders in the world, but I saw over and over that he stayed with the best we rode with, and lead many of them, while riding a YZ250F. Sorry, dude, Ranger18 is right. Even spotting 200cc, it's still 80% rider, 20% bike.

[YZ450FORD]

look i might have said wrong i know that 450s are sometimes worse than 250s on a track of course they are lighter and easier to control, and the loudness isn't a big than to me what i should have said was the sound, i want just a bit deeper cry from the stock slip on and am more interested in the performance over sound what are good slip ons you guys use or full systems thats all. I don't want to kill the sound rules and the tracks and trails:ride: