Feedback On The 03 Yz450f

i just got an 03 yz450f..never owned a four stroke..is this bike really hard to start when riding trails and it is hot? i've heard complaints about over heating..any good tips for starting when hot? or even just starting in genral? any help? thanx-josh

i just got an 03 yz450f..never owned a four stroke..is this bike really hard to start when riding trails and it is hot? i've heard complaints about over heating..any good tips for starting when hot? or even just starting in genral? any help? thanx-josh

The 03 model was very fast from the factory. Some people thought they where to snappy. They do get a little hot when ridden slow on tight trails, just keep an eye on your coolant level.

There isn't really any tricks to starting it. Pull the kick starter out and give it a good hard kick with the throttle closed and it should fire right up. If its hot, hold the hot start trigger while you kick it.

sweet! sounds good to me! thanx-josh

The hotter it is, and the sooner you have to start it after it stalled, and especially if it stalled rather than was shut down, the more likely it is to need the hot start. Do yourself a favor and put it in neutral, it will be much more cooperative.

In a stall/immediate restart situation, assume it's lightly flooded. Pull the hot start, leave the throttle alone, and kick it. Try that twice. If it's still dead, keep the hot start in and open the throttle SLIGHTLY (1/8 or less) and kick. If that hasn't produced anything, you have to decide; 1) it really wasn't that flooded (let go of the hot start and kick it with the throttle closed), or 2) it's worse than you thought (let off the hot start and open the throttle about a quarter and kick a few times. listen for faint gurgling out the exhaust, meaning it's trying to fire, but it's too wet.

If it refuses to play, open the throttle most of the way, turn it through a couple times slowly and just sit there with the throttle open, not moving the twist grip, for a minute or two to let it dry out and cool off. Then close the throttle and try a normal restart.

Remember what works and what doesn't in different situations. After a while, you'll have your bike dialed.

What's absolutely imperative for most former pinger guys to learn is that you NEVER want to do the "twist while you kick" thing that a lot of two-stroke riders do for some reason. You have to learn to hold the throttle in one steady position, whether at idle or slightly open as I described. Twisting the throttle works the accelerator pump, and fills the engine with gas, flooding it. It helps at first if you slide your hand up and grab the throttle housing with your thumb and forefinger to keep you from moving the grip.

wow! tons of helpful info! thanx a lot! i can't wait to get out and ride this thing..it sounds really awesome!thanx again-josh

that stuff sounds pretty good!

I used to put around sometimes on my 03 while following my kids. (now they can just about take me but that aside). If you ride it slow and the jetting is not right for the area, just like any other bike, mine would foul a plug but that was mainly my fault for not changing it. Mine was stock jetting. Other than that, of the 03 to 05 generation of yzf's, I think you own the best one. I loved that thing and can't really say a bad word about it other than my 06 is better. The bike never let me down mechanical wise and I never had any problem starting it cold or hot.

The 03's were beasts. Be sure you're hanging on tight when you grab the throttle!

Starting is really just a matter of knowing the bike. It may take a while, but eventually you'll figure it out.

i super love my 450. i got off a 99 RM125 that was ported and had all kindsa neato goodies on it. the first time i took my 450 to the track i wondered why i hadnt bought a 450 sooner....

cold start-

gas on

choke out

twist throttle twice

kick hard once

mine fires first time every time.

hot start- iv never had luck with anyones (anyones!) hot start kicking procedures.

dust yourself off and acknowledge broken bones. if your OK...

-find neutral

-pull hotstart lever

-kick it fast (but through the full stroke of the kickstart lever)

-no throttle twisting

usually fires within 5 or 6 kicks

the first time i took my 450 to the track i wondered why i hadnt bought a 450 sooner....

cold start-

gas on

choke out

twist throttle twice

kick hard once

mine fires first time every time.

hot start- iv never had luck with anyones (anyones!) hot start kicking procedures.

dust yourself off and acknowledge broken bones. if your OK...

-find neutral

-pull hotstart lever

-kick it fast (but through the full stroke of the kickstart lever)

-no throttle twisting

usually fires within 5 or 6 kicks

totally agree here.

my '03 yz450f was the same way. in the morning, pull out the choke, twist the throttle 2-3 times, then give it a good kick, should start right away. let it warm up and it should continue to start/run all day.

if you stall/drop it while riding, restart it in neutral!! hot start always when it's hot. and use engine ice or some other good similar coolant (FL is HOT!)

if you've kicked it 10-20 times first thing in the morning and it hasn't started... walk away.. it's probably flooded, give it 10-20 minutes and retry. i also fouled plugs often when i was first learning/getting used to the bike. carry a few spare plugs with you at first till youre very comfortable/used to your bike and how to start it both cold and hot.

that bike is a beast. i'd always get the holeshot against newer/better bikes with it.. and i had a weight on my flywheel to try to tame it! lol.

u know whats wierd....iv flooded mine so bad before (before i figured out how to start cold)..that we drug it with a truck and when it finally started spitting and sputtering, it was shooting a white mist of unburned fuel out the exhaust....and didnt fowl the plug.....im still rockin that same plug now....probably has 60 hours on it i bet...

u know whats wierd....iv flooded mine so bad before (before i figured out how to start cold)..that we drug it with a truck and when it finally started spitting and sputtering, it was shooting a white mist of unburned fuel out the exhaust....and didnt fowl the plug.....

lol, yeah, i didnt want to write that part of the story. :bonk:

that's how we used to get my bike started when i first bought it and didnt know how to start it cold yet. once we got it running, it would run the rest of the day, no problem.

lol, maybe you bought my old bike???????

just been thinking of other scenarios for you....are you comparing pros/cons to buy one?

my 450 doesnt like 1st gear for a couple miles on level 8 out of 10 jeep trails(holy cross trail south west of vail). MX bike likes to keep moving. she overheated pretty bad...

the 4 speed tranny is super limiting on anything but an MX track....it rocks out on the track but 1st is pretty tall for the slow tight stuff in the woods. the gears are spaced pretty wide apart too also can be limiting in the woods....theirs some wide open stuff i have/had ridden and a 5th speed would be awesome....

othet than that my only complaint is the tank decals....they yellow so damn fast....i put some DVS graphics on like 5 weeks ago and their starting to turn yellow already....

wow sounds like i'm going to have some fun! today is going to be my first ride on a big 450 thumper..i can't wait!! and my bike doesn't have graphics on it..maybe i will get some..maybe i won't..but if i do..i hope they don't turn yellow on me..haha..ok well i'm goin ridin! thanx-josh

totally agree here.

that bike is a beast. i'd always get the holeshot against newer/better bikes with it.. and i had a weight on my flywheel to try to tame it! lol.

I luv my 03 also...there is nothing else stock, powerwise that can touch this beast for the holeshot...and the way to get it to hook up with out all the wheelspin is the flywheel weight......now if would handle and turn like my 06. :thumbsup:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now