’08 RM-Z450 verses an ’08 RM-250 – Rich’s Story

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Up until last year I had always owned two stroke dirt bikes. Vintage Can-Am’s, Suzuki PE’s as well as more modern RM’s were the only bikes in my barn. The old ones were for vintage racing and the newer ones were for Hare Scramble racing and just enjoying the ride. For a very long time a 1990 RM250 called my barn home and for good reason, it fit me like a glove and at the zing of its exhaust note many four strokes met their match. Even bikes 10 or 12 years newer ate its dust, I’m sure that a better rider for them would have changed the results some. But we are talking about trails that I knew so well that I could ride them at speed in failing daylight.

1990 Suzuki RM250

However, I could tell that the competition was gaining and that it was time for an upgrade, so in late ‘05 I purchased a used 2002 RM250. And simply put it did everything that the ’90 did only better. The fact that it started easier and that I could actually buy a new graphic set for it from my local dealership was just an amazing thing! Once again life was sweet and while I did miss my old steed, its replacement was upholding its end of the bargain. But then it happened.

2008 Suzuki RMZ450

I won’t get into the details of it all, but the end result was that Suzuki was selling RM-z450’s at a very good price last fall. Mix in the fact that I was finally financially able to actually buy a “Brand New!” dirt bike and you could see this one coming like a freight train. Yes, I had read all of the articles about how four strokes can now handle as well as the two strokes, that their wider torque curves actually made them easier to ride and be faster with less effort! A seven-hour trip in what had to be the worse Michigan snowstorm in January of ’09 was still not enough to get me to change my mind.

My main intent behind buying the 450 was that I had spent many hours upgrading my ’02 RM250 engine and suspension just to be sure that I would be able to run with those 450’s. Pipes, silencers, flywheel weights, RAD valves, jetting, suspension work and it seem like I was never done. The 450 I believed would “only need” minor suspension work for me and my riding conditions. Once again I had read the articles and totally believed that it would not need any engine work. Well, after carefully breaking it in for 5 hours I added up what I had done. How’s 3 oil changes and 2 oil filters grab you? Yup, I did one 15 minute “heat cycle” when I got it and then I immediately changed the oil and the filter and clean both oil pump screens.

My reason for chaining the oil so soon was two fold, #1 was that I was planning on keeping it for life! #2 engines really do put a lot of “junk” into the oil during the first few minutes of break in and it was advised that I do this “just to be sure”, plus I didn’t want to wipe out a $200 cam… Oil change #2 came after 2.5 hours of engine time because I still couldn’t use “good” oil, instead I had to stick with “break-in” oil until I hit 5 hours. And that’s when I had to do the final oil and filter change (plus both screens), but at least now I could really ~ really! ride it like I stole it! Remember back when you use to be able to run a tank or two through your 2 stroke and then you would declare it broken in??

Any ways, off to the trails I went and now it was time to really lay down some fast times. On that day I did a ride with a group of guys some of which I had ridden with before, but all of them were KTM riders that hated yellow (some KTM clubs are just that way). Or maybe it was that they hated the fact that last year a bright yellow RM250 dusted them off … It must have sucked to get roosted by a bike that you deem slower than yours. Oh well, I started out slow, just taking my time getting use to the 450’s torque and weight, it was a 40 mile wooded loop so there was time to get aggressive. But it wasn’t long before I started feeling good and started to press forward. The problem was that I wasn’t catching anyone. It was hard to say but the old “you think your going slower ~ when your really are going faster” or what ever those four stroke guys keep saying started to ring though my head. The problem was, I was just going slower ~ period.

Then I started hitting the rev limiter, and for those of us that have never done that before ~ umm it’s a treat. The first time I actually thought that I just blew up my new scoot on it’s first real ride. I had to settle back down for a few minutes before I realized what I had actually done, after that I still didn’t like it but I got use to it. Even so, having your bike sound like it’s spitting cherry bombs out the exhaust is not fun and even worse if you are the guy behind that bike. Needless to say I ate a lot of orange 2-stroke dust that day.

The next 5 or 6 rides never got easier and in some ways it got worse. By then I had spent over $500 on engine modifications, like a Power Commander 5 (PCV) and an FMF Power Bomb just to get it to pull better down low and through the mid, plus the stock fuel mileage sucked. The PCV and the Power Bomb helped a lot but there was one thing that could never be over come, weight. My z450 was about 20 pounds heavier than my RM250 and I felt every ounce on the trail, the fact that the z450 is actually suppose to be one of the better handling 4 strokes seemed strange. I hated to think what a heavy and slow handling 450 would have felt like.

Around this time I started training for a local Triathlon, so I had time to think about my riding and what I was doing right and wrong while pounding out mile after mile in an effort to lower my bicycle and run time. The one thing that I kept coming back to was the thought that on my old RM250 I could flick it through and around the trees like it was nothing, but the 450 was fighting me, remember ~ most magazines agree that the z450 is one of the better handling bikes. So I spent the next couple rides playing with the clickers which ended in zero improvements and me still feeling slow. And based on how well my riding buddies were doing, I was in fact going slower than the year before. In a nut shell what was holding me back was that it felt like the 450 had a gas cap that weight about 15 pounds, and it was fighting me around every corner.

In late August after another challenging ride I parked the 450 right next to my trusty ’96 RMX250 and that’s when it all started to make sense. Just sit back and look at the design of any perimeter chassis dirt bike. All of them have the entire gas tank sitting above the cylinder – nice and high. My “older” RMX250 as well as most any other 2 stroke built in the last 20 years had a gas tank that wrapped around the engine, and with about a gallon left in the tank most of that gas was about even with the spark plug. On my 450 that entire gallon would still be well above the plug by several inches. That coupled to the fact that my 450 was already 20 plus pounds heavier and the fog started to clear.

You see, while MX tracks and Supercross tracks can be redesigned to accommodate the 450’s and the extra bulk, even to the point of offering them an advantage. My local off-road trails have not changed in 20 years, with the exception of the occasional re-route or fallen tree. I also remembered that not that long ago two strokes dominated all of the tighter off-road series. To the point where the factories would not even race a four stroke because the riders, even with factory support, were actually slower on four strokes. That’s when I put my 450 up for sale or trade.

2008 Suzuki RM250

Two months later I got an email from a guy that was interested in making a trade. He claimed to have a 2008 RM250 that was not only in good shape but was actually Jimmy Jarrett’s practice bike (yup, and I’m Ricky Carmichael). We exchanged a few photos’, worked out a deal and met half way. Turns out that the bike really was a very tricked out 2008 RM250 that had really once belonged to Mr. Jarrett, confirmed by the Certificate of Origin which had been signed off by the man himself “JJ”. Checking it over it looked like a poster child for Works Connection, but the Hinson clutch and the carbon fiber ignition cover, carbon fiber pipe guard and the RG3 DLC coated suspension was just too cool to pass up.

That first ride was pure magic. I wish that I had been able to directly compare each bike “side by side”, I can’t so let me just say this. Even though the weight difference between the two is only like 20 pounds, it’s because that weight is mostly up high on the 450 that it really feels more like 25 or even 30 pounds ~ really. That weekend I found the speed that I use to have on my old ’90 & ’02 RM250 once had. Yes ~ I actually believe that I was faster on my ’90 RM250 through the woods than I was on my ’08 z450.

As a bonus the ’08 RM250 has low end power that none of the other RM250’s had.  So much so that I dare say that it actually hooks up on the very bottom end as well as my 450. Plus my RM250 would never flame out!  Sure on the top end down a 4th or 5th gear straight the 450 was king.  But flicking it through the woods reminds me of my glory days and that it feels so good to be back on a two stroke, an and RM250 no less!  If I had to do it over I would have found either a left over RM250 or saved a little bit more and bought a KTM 300XC-We, but that’s another story.