08 yz450f questions.

14 replies to this topic
  • Joerider07

Posted April 11, 2008 - 04:22 PM


ok i just got my yz450f yesterday rode it and broke it in yesterday just putted around today i rode for awhile and when it got hot it was so hard to start even with the hot start is it just cuz its new? and is it ok to ride it at like 3/4 trottle for awhile in 5th? just wondering. the last bike i had was a 96 rm 250 and it was way different. and how long is the break in period? cuz the dealership said 20 hours and my manuel said 15 mins lol. any advice etc would be great thanks. o and its a hell of a bike lol.

  • MX926

Posted April 11, 2008 - 05:11 PM


A good hour of easy riding will do the trick to break it in. My 08 was also hard to start at first when engine was hot, once I got the fuel screw adjust properly she fires fires first kick now.

  • matts06yzf

Posted April 11, 2008 - 05:17 PM


Please put a pipe on the bike it deserves it. The stocker is soooooooooooooooo bad. My 08 is amazing

  • grayracer513

Posted April 11, 2008 - 05:31 PM


The manual is closer to right. The break in procedure laid out there is about what I do. DON'T baby it, but don't thrash it. Just take it for 3 short rides in the first hour, going a little longer and harder each time. Change the oil, and call it ready to ride.

  • Joerider07

Posted April 11, 2008 - 05:41 PM


ok thanks. wat about riding it about 3/4 trottle 5th gear i mean keeping it at a steady speed is that bad? i mean can i run 60 mph ok for a mile? or so? o trust me im gonna put a pipe on it lol its got alot of power but the bottom end could use a little and ive heard how much it comes to life when u put one on it. i was going to right when i bought it a two brothers but they didnt have the jet kit so i was like screw it ill just get it all online. any other exhaust good i mean give me some opinons cuz i wanna get the best i can and wat not. any good mods i should be right away besides exhaust anything that has shown a good improvement? and give me some websites that give good prices and all cuz its hard to find stuff for the 08. overall very happy with the bike! and how far u think u can go on a full tank? just a guess-ta-ment. 15 miles?

  • motomanmike26

Posted April 11, 2008 - 05:56 PM


personally i really like the fmf 4.1 with either the power or mega bomb header. i like both headers. your best bet for finding the cheapest is ebay. fmf's pipes are expensive. i've had bad experience with two bros with big bikes. but ive had great experiences with two bros exhaust on my 110.

  • grayracer513

Posted April 11, 2008 - 06:03 PM


Yes you can run them that hard. BTW, the shift key is the big one at either end of the second row up on your keyboard. It puts caps at the start of your sentences, and makes it easier for those wanting to help you to read your posts.

Pardon me while I get off my soap box now. :thumbsup:

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  • Joerider07

Posted April 11, 2008 - 06:12 PM


Sorry about the caps. Well ive heard good and bad things about the mega bomb. Because i was going to get it at first. Does anyone have it on a 08 yz450 on this site? Someone give me some input on the exhaust that has it. Does it need to be re-jetted? The guy at the yamaha place said it didnt need it, But from my past experiences he was just lying trying to get me to go ahead and get the exhaust. Thanks.

  • grayracer513

Posted April 11, 2008 - 06:30 PM


My experience with FMF systems in general is that they jet out very close to what a stock system does. With the '08, it could be different, because the stock exhaust, um, what's the word... Sucks.

The two biggest downsides to the Mega-Bomb are it's bulky and it's expensive. It's a good exhaust system in terms of it works really well, but I don't think it's a good value compared to other stuff.

  • Joerider07

Posted April 11, 2008 - 06:48 PM


Ok but it will make the lower end RPM's more powerful like ill be able to tell? What other exhausts are worth the money? Which exhaust would make the biggest improvement regardless of money? Should i get a jet kit also?

  • grayracer513

Posted April 11, 2008 - 07:40 PM


Almost anything you put on the bike will add 3-4 hp to the mid range below the power peak. You will be able to tell. Even a used '06 pipe will improve it noticeably. The DRD is a good exhaust, and the stainless system is in the $500 retail range, with a sparky included. There are others as well.

  • Joerider07

Posted April 11, 2008 - 08:53 PM


So do you think the DRD system would show the biggest improvement? Regardless of price. And would i need a jet kit? Im thinking about getting the DRD system but would i need to re-jet it?

  • Family Man

Posted April 11, 2008 - 09:55 PM


Check out the wb aluminum pro 2. Awsome, is the best way to describe it, pulls hard from the second you twist the throttle all the way till it hits the throttle stop. Also, there are on clearance now. Do your self a favor and install it. The dealer where I purchased my bike told me to change the oil after 10 hours. Hahahaha.....Got a sweet deal on the bike though. I would say change it after the first gallon of gas then about ever three gallons there after depending on how hard your reving and using the clutch.

  • grayracer513

Posted April 11, 2008 - 09:58 PM


So do you think the DRD system would show the biggest improvement? Regardless of price. And would i need a jet kit?

No, that isn't what I said. You'll get a good gain for the money, but whether it will give you the most regardless of price is something I don't know. I don't really care, either, at the level of power the YZ450 produces. The difference between 51 and 52 HP doesn't mean as much to me as having a good usable power curve that's there when you want it. I see it as $4-500 for one system or $8-900 for the other when they may only be within 1% of each other in performance. If I were riding at a level where that would mean the difference between winning and losing, maybe that would be more important.

DRD posts their jetting recommendations on their web page. It's not that far from stock, and you don't need an expensive jet kit to accomplish the job.

  • Joerider07

Posted April 12, 2008 - 05:58 AM


Ok well thanks guys. Im either gonna go with the DRD or the yoshimura as of right now. Thanks.

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