Moving my son up; Not so sure which bike now...

[Chaindrive]

My 13 1/2 year old finally got a chance to test ride both an '07 YZ250F and an '07 YZ125 2-stroke yesterday when his friend brought both of his to the practice track.

I was surprised how much the young man (and his father) were disappointed with the performance of their 250F. His son is much faster on the 125 and beat all of the 4-strokes at the track last Saturday night with it. He was the only 2-stroke rider in the 125B class and won!

He truly detests his 250F and he rides both it and the 2-stroke very well, but the thumper just won't perform and it hasn't since day-one they say. A local racer that is going to Loretta's and who also rides an '07 (professionally tuned) YZ250F test-rode this boy's 250F last week and also pronounced it "a real pooch". My illusions are shattering... Are they all like that or just take your chances?

I rode his 250F a little, too. (It felt so light!! I'm used to my old '99 WR400. What a difference!) But it really is a dog on the bottom end. The friend's dad claims his old '05 YZ250 F was much faster.

I'm now torn on what bike to get my son. He is getting too big for his YZ85 Supermini and he rode both the 250F and the 125 very well and looked far more comfortable on them. Oddly, he really liked the 250F. More than the 125.

What is the deal with the lack of power on these '07 YZ250F bikes? I see they are bumping the compression back up for '08, but even then the magazine reviewers say the power is lackluster.

There are many, many Blue riders around here that have gone Red, Yellow, and Green this past year. Maybe this is why? I'm also told the Yamaha parts are way more expensive than Honda's. I know there are alot of Honda contingency races around here and absolutely zero Yamaha ones, too.

I looking for a good reason to stay loyal to Yamaha... But if I am going to put 6K into a new bike, I positively want the most bike for my money that we can get. Up until yesterday, I was fully convinced that the '07 and '08 YZ250F's were the way to go. Ready to just add gas and race. Now I'm not so sure...

Can anyone with experience riding the Yammie and the other brands compare some apples to apples for me with an honest evaluation of the different bike's strengths and weaknesses. What needs to be done to get the Yamaha to make more respectable power?

Thanks!

[ttr125l95]

something i think you missed is that the yamaha's are more reliable then the others. at least thats what i heard.

there may be something wrong with his but i dont know.

[Johnnybmoto]

something i think you missed is that the yamaha's are more reliable then the others. at least thats what i heard.

there may be something wrong with his but i dont know.

They're not necessarily more reliable, Its all in the maintenance

[yamirider5588]

Advertising dollars will slant magazine reviews . The Big Four bikes are so evenly matched , it boils down to rider preference and rider skill .

The flip side is : if your aspiring racer isn't happy with a Yammie , get the one he's comfortable with . In all sports , confidence goes a long way .

Just my 2 cents

[Mr. Epeen]

13.5:1 piston and good exhaust would really boost the power. proper jetting also helps. you may want to try a different cdi also. no bikes come ready to add gas and go, they all need some tweaking. different riding conditions need different setups. also if the valves are out of spec it could cause some power loss.

[bigdrtrdr]

13.5:1 piston and good exhaust would really boost the power. proper jetting also helps. you may want to try a different cdi also. no bikes come ready to add gas and go, they all need some tweaking. different riding conditions need different setups. also if the valves are out of spec it could cause some power loss.

After my son wadded up his new 07 YZ250f we needed a new exhaust as the stock unit was bent in half. An FMF Powercore was almost 100.00 les than a stocker replacement. We already had a PowerBomb header fron our 05-06 bikes.

The FMF combo properly jetted really woke the 07 up, It is a bit louder but its no longer weak off the bottom, and still rips all the way through the rpm range.

And yes, 05s were faster out of the crate. the were also louder and were jetted better stock.

If you want a fast bike its gotta breath, Period.

Lets hope Yamahas new mechanicle baffeling on the 08s works.

[Chaindrive]

You guys bring up good points that I did not go into to, mostly because I don't know how rigorous the maintenence has been on this bike or if he has even rejetted, adjusted the valves, or tried to dial it in better. I know he said he has tried several different sprocket setups with no real difference.

I personally would not settle for leaving the bike that way (if it were our's). I, too, wonder if there isn't a combination of small problems with his bike, maybe from day-one. It runs real good on top; but a thumper without low-end is a disgrace, imho.

My son liked the YZ250F very much. He rode it extremely well, too. He likes to fool around on my WR400, so this felt as light to him as his YZ85.

He was actually jumping the 250F with better form than I have seen him use for a long time. Scrubbing the jumps and whipping the bike like he had ridden it for months. He has trouble keeping his front wheel down on big jumps with his Supermini. Not on the 250F. Probably because he is cramped on the Supermini? Corners were coming real easily to him, too, after a few pointers about how a thumper engine-brakes and tracks better&differently than a 2-stroke and to use that advantage.

All in all, we three dads that were watching found it hard to believe he was riding a 4-stroke, and a full-sized bike, (besides my WR) for the first time. He really rocked and wasn't the least bit tentative about it, clearly enjoying himself. It really seemed to suit him. But he has always been an on-the-pipe 2-stroke rider, so maybe the lack of low end didn't matter so much to him since he rode the thumper that way, too.

He has been dreaming of a YZ250F since he was on a 65cc KTM. Psychologically, he is absolutely sure he will be very fast on one, and that truly counts for something. I'd rather he rode a slow bike fast than a fast bike slow!

I guess I'm just worried that a YZ250F might require an additional thousand bucks worth of mods to find it's potential. Given the initial price, that is asking too much.

We have always been on a tight racing budget and never bought new bikes. Buying used 2-strokes has never bothered me. Easy to work on and fix right. But I do not want a used Thumper since there is much, much more to maintaining them and much more expense to fixing them. This bike may be such an excellent example of "someone else's troubles".

I'm going to have a helluva time coming up with the bucks for a new YZ250F, even with our sponsor's discount, and I sure won't have money left over for a bunch of expensive parts. That's why it had better run good right out of the box!

[berudd]

I think your son's friend is, for what ever reason, making a bigger deal out of the power of the YZ250F than there really is. I do beleive it is a little soft on the bottom as my buddy that just moved to the 07 YZ from an 06 KX250F confirmed. But not by alot and it may even help traction a tad. If this other kids bike is that bad, maybe it is due to bad jetting or some other issue.

This bike also has great suspension. I would trade raw power for better suspension any day of the week. Plus, it seems to be the bike your son wants which really does mater. He will probalby ride it better and have more confidence. Besides, unless he is look at going pro, have the bike that is more "fun" is just as important as any performance factor. Keep that in mind.

And while some try to deny it, the Yamaha 4-stroke really do have the best reliability history.

[Mr. Epeen]

You guys bring up good points that I did not go into to, mostly because I don't know how rigorous the maintenence has been on this bike or if he has even rejetted, adjusted the valves, or tried to dial it in better. I know he said he has tried several different sprocket setups with no real difference.

I personally would not settle for leaving the bike that way (if it were our's). I, too, wonder if there isn't a combination of small problems with his bike, maybe from day-one. It runs real good on top; but a thumper without low-end is a disgrace, imho.

My son liked the YZ250F very much. He rode it extremely well, too. He likes to fool around on my WR400, so this felt as light to him as his YZ85.

He was actually jumping the 250F with better form than I have seen him use for a long time. Scrubbing the jumps and whipping the bike like he had ridden it for months. He has trouble keeping his front wheel down on big jumps with his Supermini. Not on the 250F. Probably because he is cramped on the Supermini? Corners were coming real easily to him, too, after a few pointers about how a thumper engine-brakes and tracks better&differently than a 2-stroke and to use that advantage.

All in all, we three dads that were watching found it hard to believe he was riding a 4-stroke, and a full-sized bike, (besides my WR) for the first time. He really rocked and wasn't the least bit tentative about it, clearly enjoying himself. It really seemed to suit him. But he has always been an on-the-pipe 2-stroke rider, so maybe the lack of low end didn't matter so much to him since he rode the thumper that way, too.

He has been dreaming of a YZ250F since he was on a 65cc KTM. Psychologically, he is absolutely sure he will be very fast on one, and that truly counts for something. I'd rather he rode a slow bike fast than a fast bike slow!

I guess I'm just worried that a YZ250F might require an additional thousand bucks worth of mods to find it's potential. Given the initial price, that is asking too much.

We have always been on a tight racing budget and never bought new bikes. Buying used 2-strokes has never bothered me. Easy to work on and fix right. But I do not want a used Thumper since there is much, much more to maintaining them and much more expense to fixing them. This bike may be such an excellent example of "someone else's troubles".

I'm going to have a helluva time coming up with the bucks for a new YZ250F, even with our sponsor's discount, and I sure won't have money left over for a bunch of expensive parts. That's why it had better run good right out of the box!

well if that is the case, then you may want to get a new '08 that has the 13.5:1 piston with a pipe and call it good. from the way it sounds he seems to be pretty good on a yzf. i would stick with one of those. the dearlers in the area may let him ride some bikes. he could see if he likes another brand better. as far as reliability goes all makes seem to have come a long way but, the yammies seem to be a little more reliable. maintenance on a 125 is going to be less than any 4stroke. if he rides as good as you say, he may be able to compete on a 125. most of it comes down to who is the better rider anyhow, not how much power a bike has.

[Chaindrive]

That is an excellent point about a "softer" bottom maybe actually helping maintain traction. The suspension and handling did seem very good. I have been perusing some posts and it sounds like the higher compression piston (like the '08 has) and a better pipe (FMF power bomb?) along with corrected jetting really help wake up the low-end.

My son and I are both die-hard Yamaha fans and I have always admired their reliability. I thought the YZ250F was going to be awesome when they introduced the aluminum frame. But then they had valve problems and some steering/suspension problems.

In '07, they addressed those issues , but kept the ugliest pipe on the planet and traded performance for quietness (on a racing bike?!). Now it appears that the lower compression of '07 ('06 too?) wasn't such a good idea. The '08s have bumped it back up and done some changes to the exhaust muffler. Maybe they have it closer to being "right" now?

He isn't going to take the bigger bike straight to the podium, but I say that every time he moves up a class, and somehow by the end of the season he finds a way to be standing somewhere on it. So if he believes in the bike and enjoys it and it doesn't break the bank to keep it, it is probably the way to go.

Does the boy bleed Blue? When that 9-year-old brought his YZ85 home 4 years ago, he and his mom had a truly serious disagreement about whether or not he could keep it in his room with him! ? I think he's even more infatuated with the YZ250F. It could be worse; he is at the age where it could be girls... bikes (even 4-strokes) are way easier to explain and maintain! (fewer moving parts?)

I know it always comes down to the rider. That's why I would rather have him riding fast on a "slow" bike than riding slow on a "fast" bike. As long as neither I nor anyone else talked him into believing the bike was anything but "perfect", he would believe in it and figure out how to ride it fast.

Thanks for the input guys. I guess there really is no "perfect, ready-to-race bike", but if none of the other brands really has a margin on the Yamaha, we'll probably stay Blue and try the 4-stroke.

[davidl9999]

...we'll probably stay Blue and try the 4-stroke.

You can always get him a white one! ?

[muffinman]

all the big manufactures bikes come out of the crate with very similar performance. however its a fact honda still has valve issues, yamaha are extremely reliable bikes, but it is always 90% rider 10% bike:prof:

[518country29]

haha, my 07 is a beast IMO, its kinda doggy on the bottom, I tossed on a 52 tooth rear sprocket haha, bit too much but adding a tooth or two will do it for these bikes, the next thing im buying for the biek is hot cams stage 1 that woul dgive the bike the bottom they were prolly lloking for, have your son test ride and see what he likes

[Chaindrive]

One of the tracks we race frequently is an outdoor Supercross track: corner/jump; corner/jump; etc... Having explosive low end is important to make it over the jumps which often start immediately out of the sometimes flat, hard-packed, and slick corner (meaning slower corner speeds). The 4-strokes do and should have an advantage there, but only IF they have good low-end power.

For the reliability issue alone, I would stay with Yamaha. That means I won't have to buy a new hat! For his part, there is no decision to be made. He hasn't even expressed a desire to try any other brand.

We have agreed that we like the white ones best, though we will probably immediately change the plastics out for our traditional Strike Eagle black. You have no idea how happy I am to see an already black tank...

As long as the low-end can be fixed, and it sounds like it can, I think an '08 YZ250F will be his next bike. I'm going to forgo the '07 and avoid the hassle of finding and installing a higher compression piston. Maybe the '08 won't even need any low-end tweaking...?

That would leave figuring out what, if anything, the suspension would need to accomodate his 135 pounds. Of course, last winter he grew nearly 4 inches and gained over 30 lbs in just 4 or 5 months... All the springing and valving I did to his Supermini and YZ85 last fall went right out the window by spring...

What is your experience with the stock '07 (and I assume '08) suspension settings from the factory? Is the bike going to need revalved and resprung for say, a 140 pound rider? What is the ideal rider weight for the bike in stock form? A lead-filled belt and a bunch of Twinkies might be cheaper than a softer suspension... Seriously, if money dictates I choose between more low-end power or improving the suspension, it will have to be the suspension first.

Anybody else have a light rider on one of these and how is the stock suspension for him or her?

[davidl9999]

You should always have a pro suspension shop revalve a competition bike, even if the charts say that what you have in there is correct. He will be a happy camper, struggle less, have a safer bike, and probably ride faster. ?

I'd just consider it part of the purchase cost of the bike. That goes for power mods to keep him competitive as well.

[skatpex99]

You can always get him a white one! ?

Everybody knows that white is the fastest color.?