Posts
2410
Joined
11/2/2011
Location
Chapin, SC
US
Edited Date/Time
1/1/2015 8:55am
Right now I have an 06 CRF 450, it's a great bike and I've done well on it but I am put off by the cost and frequency of engine maintenance. I've spent the past week working on a friend's YZ 250, and more and more I have to wonder if an 06+ would be a viable way to make a reliable and affordable Vet class race bike, with the right mods.
Have no illusions, this isn't about building a top end rocket, I need it to perform similar to a four stroke. I don't want to fight a massive midrange punch, I want to roll it on through the corners and in the off-cambers. I need it to be forgiving when I screw up and when I get tired. Also part of the equation, my track here is slick and hard pack, so having a bike that can hook up is more important than one that can win a drag race. I'm a 42 year old Vet B rider, 158 lbs, BTW.
What I want:
- Similar to one in the article Jody did in XA, I would want to punch up the power. The 285 kit, a pipe, and reeds seem like a good start.
- Then try to mellow it out (9-12 oz flywheel weight?). Possibly taking a tooth or two off the rear sprocket to try and make the gears pull longer.
Has anyone else gone this route? I plan to ride my buddy's bike this weekend, but it's an 01 and I have no idea how good or bad the suspension might be. I'll try to get some lap times against my 450F just out of curiosity. Is this winter madness that I am even thinking about this?
Have no illusions, this isn't about building a top end rocket, I need it to perform similar to a four stroke. I don't want to fight a massive midrange punch, I want to roll it on through the corners and in the off-cambers. I need it to be forgiving when I screw up and when I get tired. Also part of the equation, my track here is slick and hard pack, so having a bike that can hook up is more important than one that can win a drag race. I'm a 42 year old Vet B rider, 158 lbs, BTW.
What I want:
- Similar to one in the article Jody did in XA, I would want to punch up the power. The 285 kit, a pipe, and reeds seem like a good start.
- Then try to mellow it out (9-12 oz flywheel weight?). Possibly taking a tooth or two off the rear sprocket to try and make the gears pull longer.
Has anyone else gone this route? I plan to ride my buddy's bike this weekend, but it's an 01 and I have no idea how good or bad the suspension might be. I'll try to get some lap times against my 450F just out of curiosity. Is this winter madness that I am even thinking about this?
I race a 2010 KX250F and I also have an 07 YZ250. The YZ is stock and while it's fun to ride in sand or loamy tracks, it is more physically and methodically challenging to ride. When I'm fatigued, the two stroke becomes a great chore to ride. On the 4t, i can get by fatigued because the bike is so much more forgiving. With that said, Im not a serious racer and I sometimes can't decide which bike to ride. But If I were looking for results, without a doubt I'd be riding the four stroke.
As far as maintenance frequency and cost, the YZ has cheaper and fewer wear parts but I don't find the four stroke to be substantially more expensive to maintain in my experience. As long as you don't experience a nightmare in the cylinder head, the cost of maintenance should be close to the same.
Personally, If I were you I'd look for a more modern 450 or maybe KTM 350. I actually owned an 06 CRF450 and it was a great bike. But they've come a long ways since then.
My 06 has been a great bike, but it's at the point where it is going to need some major maintenance fairly soon (cylinder/piston/new valves/head recut/misc, probably totaling around $1K in parts) if I want to keep racing it at this level and be confident in it.
There is an 08 YZ 250 on my local craigslist, with Athena 285 kit and FMF pipe, for $3K.
I last raced a 250 two stroke a year ago, but it was a 1994 KX 250. I dropped 8 seconds/lap when I went from that bike to my 450F on the exact same track. And that was before I got my CRF suspension worked.
Right now I have to be careful on budget as I'm getting close to military retirement and can't obligate funds for a newer bike. After I retire and get a "real job" a current bike will probably be feasible.
Yeah, this whole thing is probably just romance. After I ride the 250T this weekend it will probably sober me up on the idea!
The Shop
I've ridden it a few times. It's not just a top end rocket, the whole powerband is just a ripper. It has a shit ton of bottom for a two stroke. There is not much of a hit, especially with the rekluse, it just hits at the very bottom and rips all the way up to the top. Especially with the widened Trans.
It's not much of a vet racer, more like a open class weapon. If you just want abundant power and torque it's there. It can definitely hold it's own with 450s. Plus it's super light obviously.
Straight up, if your looking for a super light 125 like bike that will rip your arms out of there sockets, this is your choice. It's like a turbo hayabusa vs a fast v8 muscle car.
Gotta say I love the bike. It sounds AMAZING.
Yeah, the guy who normally wins our Masters (+40) class runs a 250F. He's a great rider, but part of it is the fact that a 250F cuts great lap times on that slick track.
Kawa448 that build sounds like definite overkill for what I'd want! Sounds great on a prepped, softer track though!
I think the punchline here is that rebuilding my CRF sounds like a better plan. Especially since I just got he suspension worked a few months ago by Factory Connection.
250 2T
450F
In all fairness to the two stroke, after a year of riding that track, I can tell that the conditions during the 450 ride actually would have had better traction. Either way, 8 seconds is a pretty big chunk, and that was on average, not just a good lap on the 450 compared to a bad one on the 250.
I hope to do some back-to-back comparisons this weekend.
Pit Row
that is me in front of the gopro guy blue TLD gear
However, as soon as you said things like "roll it on" and "slick hard pack" I knew the 450 is a better choice for you.
I still think revalved suspension and some common sense mods would get some of that back, but by that point I'm in quite a bit of change for something that still might or might not work better.
A few of my buddies rode it too, and every single one of us got off of it with big grins. There is no feeling like riding a two stroke, and if I wasn't racing, this would be a no-brainer in favor of premix.
Post a reply to: Thoughts on building a YZ 285 4T killer?