2003 Yamaha Yz450F

[dlholder21]

I am looking at a 2003 Yamaha Yz450F bike. I have not got to test ride it or check it out in person yet, but what is yalls opinion on this bike? I know that this is the first year that Yamaha manufactured this bike but did it have any problems? What are some things i need to look for on this specific bike? Is it a reliable and fast bike? The reason i need to know these things is because i am a honda man and i have no clue about yamahas. So have at it and let me know
thanks

 

[mideastrider]

Friend of mind has had a 03 450 for about 3 years now. He has no problems out of the engine. The only problem I know of is the kick crank shaft broke off and had to be replaced. He looked for a used one but newer models would not work because they increased the size of the shaft by about 2mm. Makes me think his is not the only 03 to break a kick crank shaft.

 

[Matt90GT]

With any of the older than 07 Yamaha 4 strokes, you need to buy an aftermarket plug for the head where the manual decompression shaft came through. The stock rubber freeze plug has a way of blowing out.

Other than that, with good oil they are pretty bulletproof. The 03 was the first year of the 450 and had a 4 sp tranny. The motor is VERY explosive, infact yamaha discontinued the cam. You can add the GYTR flywheel weight, but it will make the bike faster since it is hooking up and not spinning. They are very fast stock, jetting was just about spot on from the factory.

Stock they handle horrible. You can swap over the new forks and trees to the twinchamber stuff off the 05+ bikes to help, but they are not known for handling.

The Honda CRF450 is an overall better bike, especially the 04 model or the newer gen frame the 05+ bikes.

 

[sharky243]

Hey,

I have the same bike. All I can say is awsome!!!!. I've owned it since new and it has been very reliable. The only thing to watch is the lower shock bearing collects water when you wash the bike, and the front wheel bearings tend to go bad frequently do to the fact that the seals don't do a good job of keeping the water and dirt out. I have probably close to 400 hours on it, and the bottom end is still origonal. I've only replaced one intake valve, and normal top end re-builds. I did re-jet it from stock, #160 main, and a #50 pilot. I would say it is the best 450f that yamy built. I've heard of people dyno-tuning the 03's and getting over 53 hp. out of a stock engine. As for how I ride it, pretty hard. I used to race it every weekend and it never let me down. One thing to note though, some early production 03's had sticky shifters. Sometimes it would not return. This was caused by a simple burr on the shifter shaft, easy to fix. They fixed this problem for later production 03's. With regular maintanence, you will get a liftime of riding out of this bike. The bike handles like it's on rails, basicaly just point and shoot. Just make sure you set the suspension up properly including race sag. I use 5wt. fork oil at a 135mm level. 3.5" of sag. I'm 6ft, 180 pounds.