I am still trying to figure out that post about the 450R being tippy? Nobody ever said that about the 400EX, so wonder why now the 450R is considered tippy? It has pretty much the same frame geometry as the 400EX???

 

I think the YFZ would be better for GNCCs or harescrambles than the 450R that would be because the YFZ is electric start and that would work better for their dead engine starts. Both of these quads are going to have to be maintained like a 2-stroke simply because of the flat piston design. You get any wear in the cylinder and that piston gets too much play you will end up breaking the skirt off of it and tear up the motor unless you keep the topend fresh.

 

True, but there were also a lot more yfz's in the running than R's. Just as there are many more yfz's on the nation's mx tracks than R's. So expect to see more DNF's and problems.

No one said they were reliable, he wanted to know whats best for MX. You should be gusseting your frame and subframe for MX anyway, I think dirtgirl's friend needs to learn that. You need to take preventative measures and keep the quad maintained. The 250R is an incredible machine, but you need to take care of even newly built ones too keep them competitive. I stand by my recommendation that the yfz is the better mx machine, the R is simply not as good on the track. The R is a great machine, I have no desire to put it down.

 

I'm on my 4th Sub Frame but this one will last longer for sure 6 point buck Buy this Right away and save yourself some money before replacing with a stock sub frame or 2... Trust Me !!!

2nd Engine , 2nd set of right front A-arms , 2nd right front shock , 2nd steering stem , 2nd rear axle and 4th set of handle bars ..

I Ride 2-3 Days a week but I don't ride that hard or Race mx .. The above mentioned parts are not from an accident either the stock parts on the Yfz are just not very durable , With the exeption of the engine the first one I got was a bad egg.. the sub frames break easily and the front A-arm snapped while going up the face of a jump ( not landing ) , the shock busted when I landed so I honestly can't say that the shock was not durable But the A-arms and sub frames do not hold up well !!

 

Like I said...

 

Well tell me this then, if they are not reliable, then why would they be the best choice for MX then? Wouldn't something more reliable be a better choice? If you read the original post you will notice that he also asked what the mechanical flaws were of these machines. That is what I was trying to bring out in these posts.

OH another thing to consider...... Pro Quad Champion this year was on a Suzuki....

 

For the same reasons why the Arctic Cat F7 is so popular. It doesnt hold together well, but its very hard to beat.

I do not fault you for pointing out its flaws, as you said the poster asked for them. I was just trying to point out that you rarely see quality and the ability to produce in the same machine. Its as if one is necessarily sacraficed in favor of the other. Honda makes sacrafices in the name of reliability and safety, which are very evident in the 450R with everything from engine design to carb choice. Yamaha did not make those sacrafices, but their machine is much faster to fall apart. I was just trying to point this out. But when you go through that many subframes, as your friend did, then you should have realized after your 3rd replacement that you needed to try something different like strengthening it considerably or purchasing an alternative like yfzinsanity did.

The pro champ was on a zuki yes, but the pro series wages just as much or more on the rider than it does on the machine. Same rider on a similarly equipped yfz and I believe he would be turning faster times. It would not be fair to compare a Z440/450 with long travel, extended aftermarket suspension to a stock yfz. That is why the two atv's should be similarly equipped when comparing, as many of the pro machines are. But then you are back into different rider skill...

 

I hear it all the time; my honda is better then yours or my yamaha is faster then yours. Who cares. I weight about 245 lbs and ride/ race MX with a yfz that has stock shocks and so forth except for axle, tires and handle bars, not to forget kill switch. let me tell you that I have not had a single problem with it. I highly recommend the yfz to any one. I had a trx250r for many years and it gave me tons of headaches. I think all major brands are reliable and all break down as well. I think it has to do with many factors why any atv breaks or not. I rather be a faster rider on a slower atv then a slower rider and a better bike; it just makes things a little more interesting. Its all about the competition.[img]i/expressions/face-icon-small-mad.gif[/img]

 

You want to try something REALLY interesting? Try racing an open cc MX class on a 300EX... [img]i/expressions/face-icon-small-tongue.gif[/img] That can be pretty interesting to say the least! I got 5th place at the state championship on a 300EX racing against guys on YFZs, 450Rs, Cannondales, Raptors (one of which is punched out to 720cc), a Banshee, some bored out 400EXs and some Z400s....... I am racing the smallest quad in my class. I could go big and race the Zilla, but I would like to be able to finish ALL the races I start... [img]i/expressions/face-icon-small-wink.gif[/img]

 

Thanks for the info everyone.

I do understand that a stock ATV will not hold up under extreme riding conditions or MX because of their weight. I do intend on adding the right aftermarket parts to which ever bike i purchase to enable it to better with stand extreme riding conditions. My concerns with the two 450s mechanical flaws was primarly the engine because they have not been on the market very long. But i was also concerned with their stock frame. I also think Honda tames their ATVs due to the lawsuits they encountered from the 3-wheelers in the 80s.

My biggest concern with the Yamaha was the remote oil tank and the electric start (something else to worry about). Also on the Yamahas does anyone relocate the rear brake master cylinder? And where? It just seems like it is in a bad location.

Does anyone know the AMA rules for the bike setup in the Production class? What changes can you make and not make?

Suzukiyamahaman,
I do not know if there is a MX track in Oxford. I started this profile when i was in college there.