now I'm puzzled


23 replies to this topic
  • YZ250F_Rider

Posted September 10, 2004 - 03:58 PM

#1

I just ran my 450 up and down the street once to warm it up. It was the first ride for me on it.

Arent these things supposed to be fast? I dont think it's any faster than our 250's are. Granted they are modded, but man I was really expecting more from it.

I suppose it's a good thing though. If it was way faster I might have a time adjusting to it. Luckily it has twice the piston so some good modding on it ought to make it perk up.

  • Fastest1

Posted September 10, 2004 - 04:59 PM

#2

You might actually be faster on the 250 but not quicker :thumbsup:

  • YZ250F_Rider

Posted September 10, 2004 - 06:20 PM

#3

well thats my concern. It doesnt accelerate like I would have expected.

I did notice some excessive poppin on decel, so at least the pilot circuit is lean (so much for the wand in the pipe at the dealer saying it was rich at idle :thumbsup: )

It could be it's just jetted too lean to really make any decent power. I'll know better tomorrow after some saddle time, and checking the jetting.

  • racerxj17

Posted September 10, 2004 - 09:23 PM

#4

i dont know about you, but i couldnt tell you how fast my 450 really is on the street, b/c before i can give it full throttle, its trying to flip me over.......even in fourth the front tire does not like to stay on the ground. you must have one damnnnnnn fast 250.
jon

  • Hamish

Posted September 11, 2004 - 01:43 AM

#5

wait 'till you ride it on the dirt. I'm sure you'll opinion will change. To me they dont feel as quick as the 2 smoke, but the stopwatch never lies!

  • YZ250F_Rider

Posted September 11, 2004 - 03:55 AM

#6

We are just getting ready to go riding, so I'll let you know how it goes in the dirt. It may be nothing more than the rear sprocket needs a couple more teeth. At least thats what I am hoping for. :thumbsup:

yes the 250's are damnnnn fast. :devil:

  • YZ250F_Rider

Posted September 11, 2004 - 12:02 PM

#7

well we got back from riding.

Holy moly that bike will wear a lazy dog out. I wouldnt have guessed 20 pounds would do that, but I am beat. I will be needing to train now. :thumbsup:

I still feel that the 250's are quicker. They definitely rev faster under load by a long shot. I am pretty sure a couple of teeth on the rear should cure my blues though.

Man I love that tractor feel. Click it into 3rd and let it pull the house along with you.

The forks are way better then the 04's. Even with the factory syrup in them, they are plusher and smoother feeling than the 250's.

I am really glad it fires so easily too. It spins a lot slower when kicking it than the 250 does, but it fires really easy. It fires at such low rpms that it's really surprising.

Other than the weight and the better feeling of the forks the ride feels just like the 250. So adjusting to it was not an issue.

  • grayracer513

Posted September 11, 2004 - 08:03 PM

#8

Now I'm more interested in getting a ride on your 250 than on an 05 450 :thumbsup:

  • YZ250F_Rider

Posted September 12, 2004 - 03:31 AM

#9

LOL.

you know I am wondering if they didnt throw a wet blanket on the ignition map. This thing doesnt have any sense of a hit at all.

I really dont recall having to squeeze the bike with my knees to hold on while accelerating yesterday at all. It never had me feeling it was going to leave me sitting in the dirt. Maybe I'll look around for an 03 or an 04's cdi and go up a couple of teeth and see what it does.

We are heading to the track this morning so I'll see how it flys.

  • Hamish

Posted September 12, 2004 - 03:46 AM

#10

This thing doesnt have any sense of a hit at all.


Thats what Yamaha intended. Everyone complained of the hit on the 426. Maybe you bought a lemon?? :thumbsup: cuz even my ol' 426 requires plenty of throttle control to prevent it loopin' out in 1st,2nd and 3rd if u have traction.

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  • YZ250F_Rider

Posted September 12, 2004 - 11:39 AM

#11

well it's official. Yamaha has detuned the 450 into pansy bikes. It's not as fast as our 04 250's.

I rode 10 or so laps at the track, and then jumped on my kids 250. It was like night and day. The 450 doesnt even come close to matching the acceleration of the 250. It takes for ever for the engine to wind up on it.

I will let one of the guys at the shop ride it next week to compare to his. Hopefully they will be able to determine what detuning yamah has done so we can fix it.

  • av

Posted September 13, 2004 - 08:06 AM

#12

I've been hearing that they've been detuning the 450s since 03 when they first came out - back then, even the pros complained that it was too hard to ride/handle. Yamaha has been mellowing the engine/hit out to make it more ride able like the CRF450s - big sellers for Honda.

Looks like they have made the YZ450Fs more like the CRF450s to sell better and to be easier to handle/ride. I rode an 03 YZ450F a while back and it was a sick/scary bike to ride IMO but I haven't checked out any newer model YZ450Fs. The 04 CRF450 I rode was fine for me to ride but that 03 YZ450F had a bigger hit and I just had to hang on, I barely got into 3rd gear on the track with that thing... :devil: :thumbsup:

  • YZ250F_Rider

Posted September 13, 2004 - 09:36 AM

#13

I am going to make sure the cams didnt get installed out of time, and I have a performance cdi coming for an 03/04.

I see they changed the primary gear ratio too, so I will probably try a smaller front sprocket too.

somewhere the beast lies within, hopefully I will piss it off eventually and make it come out and play. :thumbsup:

  • av

Posted September 13, 2004 - 12:39 PM

#14

Check your flywheel weight too, I heard they may have made it heavier hence the slower revs... :thumbsup:

  • YZ250F_Rider

Posted September 13, 2004 - 01:34 PM

#15

hmmm good point. I'll have to check that.

  • simch

Posted September 16, 2004 - 02:34 PM

#16

Try richening the main jet too. Made a big difference on my WR, but to be fair it was pretty quick to begin with!

  • grayracer513

Posted September 16, 2004 - 04:15 PM

#17

Flywheel weight has the most influence over the engine when it is in neutral, when there is no other load for it to work against. Underway, it also affects the engine's behavior when the bike breaks traction, particularly at low speeds. That is, a bike with a light flywheel like a stock '03 will blow up the rear tire and act like a 2 stroke, whereas with a few extra ounces, like the 5 extra Yamaha hung on the '04s, it jumps the revs up a little slower and more controllably under these circumstances. You can take 2 otherwise identical 450s, one with a light flywheel, one with a heavy one, and run them side by side in 4th gear and see almost no difference in their acceleration or speed.

If this bike is a normal example of how the '05s run, then I agree that the "problem" is most likely a timing issue with either the cams or the ignition, and could even be a different grind of cam altogether. That would make it easy to fix, though too.

  • YZ250F_Rider

Posted September 16, 2004 - 04:32 PM

#18

actually as it turns out the part numbers for the flywheel are the same for the 03's and the 04's. Apparently all that was done for the hit on the 04s was a remapping of the ignition. The shop doesnt have the 05 microfiche yet, so it remains to be seen if it was swapped out for a heavier one this year.

If the mail order place wouldnt have screwed up my order I would be able to tell if the ignition and gearing is all they did to kill it this year. They wound up sending me a CDI for the yfz450 atv.

Hopefully tommorrow we will know something more.

  • ovrrdrive

Posted September 17, 2004 - 01:27 AM

#19

Well, if I ever get a day off and we can get together, I'll let you ride my '04 and see if that's any different. The only thing I've one is change a few jets and a 13T front.

I haven't even gotten a chance to ride it since I put the sprocket and new pilot jet in. We're still working 12 hours a day, 7 days a week. I figure we'll probably have a couple of more weeks like this, then they'll probably give us our weekends back. We'll see... We really got torn up pretty bad from Frances.

My bike seems pretty quick, but then again, its the first dirt bike I've ridden in like 15-20 years.

  • YZ250F_Rider

Posted September 17, 2004 - 02:22 AM

#20

Thats cool.

Man you must be working yer butt off. I'm sure you know, but everyone thanks you guys.





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