General Discussion Forum

Here is where we can discuss the Dirt Rider Web Test of the 2009 Yamaha YZ450F.

Editors will frequently respond to sensible questions you post here.

JIMMY  
JIMMY
Editor Dirt Rider Magazine

How many horsepower does the bike make?  
'Forgive me Lord for I have sinned; hit a 4th gear jump 5th gear pinned'

Real Men Ride Four Strokes-Always Have.

I don't see why HP matters, its a 450 for gods sake...

Did you guys get to test it at other tracks yet to see if the handling has been improved. Pat at TWMX says he has nothing to complain about on this bike. Do you guys agree?  

2009 YZ250F Long Haul

You'll see the full test up shortly! Yes, three tracks in 6 days and 10+ hours in the saddle testing.  
JZ

Invite your friends to the dirtrider.com forums and win free advice from Jesse (worth every penny).

will we see the full test online or do we have to wait until the sept issue??  

          post count means nothing
06yz125,kx60(2)

Yamarider, yes it makes horsepower. Since I think dynos are as useful as TWMX, we don't put our test bikes on them much. The YZ makes plenty of power and dynos are as different as the guys who use them. I suspect the bike is in the high 50s if I were to venture a guess. It is more than most riders will ever need.

MJP, Yes, the test is live and online, but you can still wait if you want a surprise.

JIMMY  
JIMMY
Editor Dirt Rider Magazine

Yumping Yiminey, Jimminey - er, Jimmy!  

DR actually posted something NEW on the site!  I was getting tired of reading the same tests the past few months - the off season SUKKS!

Can't wait till the review of the CRF450 comes out!  
**

Here we go again!

You guys state that this bike is made to run strong with the mechanical restrictive muffler. I thought for 09 Yamaha changed this to a straight through design, eliminating the internal baffling.  

2009 YZ250F Long Haul

Never mind, I was getting the new YZ250F's muffler confused with the 450's one.  

2009 YZ250F Long Haul

Sorry I get a lil jumpy to know how many ponies I have that my friends dont. lol

Ok I have a very good question. I know that the previous Yz450s could be shut off if you gave them throttle too quickly and that they were easily flooded. Also there is this really nasty bogg spot on the yz-fs that is right off throttle opening up to about a grand higher. Is this fixed for 09 because it was a terrible trait.

I also know that Yamaha has wheel bearing issues and the bearing seem to go quicker than other brands. I know its very earily to answer this but how good are the wheel bearings holding up?  
'Forgive me Lord for I have sinned; hit a 4th gear jump 5th gear pinned'

Real Men Ride Four Strokes-Always Have.

Since the bike pulls a tall gear so well, it is easier to give it too much throttle and get it to stall than on bikes that do not have as much torque, and don't like to be riddden in this manner. This is usually a rider error, but with FI coming riders can be a lot more sloppy with the throttle and get away with it. We had no issued with the jetting or any bogs.

The rear hub is all new and now has three bearings. I was not aware of the durability issues. The axel is larger as well.  
JIMMY
Editor Dirt Rider Magazine

from talking to people and seeing them with my own eyes, the 08 and even some of the 07 450's seemed to be really short. this doesnt look the case in the pictures i looked that but i am just wondereing if the bike comes stock set up for a taller rider or not...  

Im also hearing that Yamaha has changed the rear wheel size for 09. Is this correct? I heard it is a bigger tread. Is this going to effect the handling and the already pushy cornering?

Have the cams been revised for 09. I know that from like 05 from 08 has different cams. How about this one?

The muffler is the same as 08 as well isnt it? It almost resembles a 2 stroke look because of the lenght.  
'Forgive me Lord for I have sinned; hit a 4th gear jump 5th gear pinned'

Real Men Ride Four Strokes-Always Have.

yamarida97:
Im also hearing that Yamaha has changed the rear wheel size for 09. Is this correct? I heard it is a bigger tread. Is this going to effect the handling and the already pushy cornering?

Have the cams been revised for 09. I know that from like 05 from 08 has different cams. How about this one?

The muffler is the same as 08 as well isnt it? It almost resembles a 2 stroke look because of the lenght.

Axle went from 22mm and 2 bearings to 25mm and 3 bearings. The hub is 265 grams lighter too.

I believe in 08 the YZ got the different cam and the 09 retains it.  

2009 YZ250F Long Haul

Oh I see what you mean. The 08 and the 09 are probly the most identical yz450s built so far then.

I know about the axle change. I was asking about the rubber and rim size has changed Pin_it. Do you know?  
'Forgive me Lord for I have sinned; hit a 4th gear jump 5th gear pinned'

Real Men Ride Four Strokes-Always Have.