best 2004 yz250 upgrades

[yz250474]

My first dirtbike.. I will be trail riding until I get used to 2 wheels (I got a raptor 660) and this crazy powerband.i want to try the local mx track... I would really like to make it smoother, I'm confused because all the magazines talk about smooth power delivery for the yz250...I have rode a friends yz125 about 10 years ago and was pretty comfortable on it, I was practing starts wide open walking wheelie, its power seemed smooth to me, but this 250 is like a light switch? I do only have 30 minutes on it.... and if its anything I should know of these 250s I'd appreciate it

[yz250 947]

I ride a 250 also,but mines a 98', and its like a light switch aswell...but I couldn't imagine enjoying it half as much if it wasn't. I ride mx only,I trail rode it one time so far and it was a handfull. The only thing I would change if I were to just trail ride to smooth it out some might be a flywheel weight. I was riding a 250f before the yz,and its just seat time to get used to the powerband,but thats just my opinion.

[yz250474]

I'm considering a flywheel weight, I've seen it brought up a lot... I was really looking for a yz125 but come up on a good price for this yz 250, I think I just need some time and ill be ok... I went with the 2 stroke because of rebuild prices, I remember liking the hit of the yz 125, 

 

Yeah I love the hit, its not a lot that can get my heart rate up like this 250,  I popped a wheelie higher than anyone would ever want to on  my second attemp, lol lucky I won't digging dirtout my teeth, it got my heart pumping and parked it...lol a lot of respect for people that just pin it thru the whoops and triple 100ft jumps...  my balls got some growing to do before I'm on that level

Edited December 23, 2013 by yz250474

[yz250474]

Do you know the differences from the 98 to 04 motor?

[shrubitup]

99-14 mostly same motor. In 03 the flywheel got larger. 

[MANIAC998]

Do a search on how to tame the hit down. Lots of information out there. One thing to do is to check your ignition timing. This fixs most of the un-controllable "hit".

[bobbyward]

My 250 never was a on and off type. Slowing down timing would help, running a larger counter sprocket helps along with a heavy flywheel weight. Jetting might need to be tuned a little better also. So many thing to do to make it a pleasure to ride. Just pick your poision .

[yz250474]

I should be able to practice a few hours this weekend, but I do plan on checking the timing... I'm going to read up on that when I get time... I'd prefer to watch a video about it, if anyone knows of one...

[adam8781]

Look at the yamaha FAQ at the top of this forum.

 

read the timing threads:

Set the timing on the motor to 1 degree retarded, this softens it up a bit so there isnt as much of a hit down low.

 

Read the squish threads:

the stock squish in the yz250 head is to big, do a squish test, and send it to rbdesigns for machining and setup for the kind of fuel you want to run. ( i suggest .045 inch squish)

 

These two things alone are dirt cheap todo and would make a huge noticeable difference in how the motor runs.

 

Thirdly: 10oz flywheel weight will also help to smooth out the hit. Yz250 isnt a light switch, its just takes much greater throttle control than you are used to. And compared to say a cr250 or rm250, the yz has alot more lowend power!

[yz250474]

I believe you are right, I got to get used to the throttle.. I'm used to a raptor 660.... its powerful but a lot more predictable as of now.... I'm going to put some time on the yz and ill let you guys know what I decide to do....I'm just waiting on a shifter and airfilter now.... Im praying they get here b4 the weekend!

[shrubitup]

And compared to say a cr250 or rm250, the yz has alot more lowend power!

100% correct. I didn't believe it so I tried a 98 99 01 and 02 cr250. No luck with low end power there. Only owned a 00 rm250 so not really a good sample there. My new husky defines low end power however. ?

[bobbyward]

That 295 yz motor has some serious bottom end too. So smooth....