Two-Stroke Or Four-Stroke?
Story by Tyler Belknap, Photos by Trevor Hunter
It’s a timeless conversation you’ve had with yourself, your wallet, and likely your wife. Keep the bike you have and put some money into it, or simply buy a new bike. We’ve been loving our time with the 2020 Suzuki RM-Z 250 and it prompted us with that age old question. These new Suzuki bikes are attractively priced, giving the consumer an easier chance to get on a fresh ride or leaving them room for upgrades that they might not be able to afford with the other brands. On the other hand, there’s a never-ending shortage of “Craigslist Specials”. Building a project bike can be cost effective (if you do it right) and allows you to build a bike your way. So what’s the best option, brand new or brand used?
We found this 2005 RM250 for $1000 while scouring the online depths of Craigslist and Facebook Marketplace. At one point in time, this iconic machine took Ricky Carmichael to multiple Supercross victories and was the last two-stroke to win a major championship. Unfortunately, this particular bike had seen more sand than Supercross in its heyday and was listed online with a blown top end at minimum. We deemed it perfect for our RM Rebuild.
Our goal was to rebuild this RM250 for about the same price as a new RM-Z. With budgets in place, we aimed to make this bike competitive without going off the deep end like some of the other media outlets.
The suspension revalve from TCS Powersports was the only modification made to our 2020 RMZ 250. Despite the newer components and a modern-day revalve, the 2020 bike still fought against it’s ultra-stiff chassis. I struggled to find that perfect setting on the RMZ as the Glen Helen track wore out during the day.
In the opposing corner, the 2005 RM 250 had a full rebuild and revalve from AHM Factory Services. The lightweight two-stroke noticeably handled the choppy bumps in a much more forgiving manner and allowed me to ride harder for a longer period of time. Coming off a YZ 250, the chassis and suspension on the RM provided more of a seamless transition than that of the four-stroke counterpart.
The motor on the new RM-Z needs some fine-tuning to bring out the real excitement on the track. Glen Helen’s hilly terrain and wide-open straightways leave no room for compromise. Power is king here and I felt like I was ringing every last horse out of the RM-Z. I was looking for more low end coming out of the corners and really wanted more mid to top end power as I accelerated up the famous Glen Helen hills. On a positive note, the RM-Z power is not terrifying and allows the rider to remain in control throughout the course of a moto.
The RM had a more raw aura to it as you listen to the two-stroke power ring throughout the rpm range. The FMF exhaust system and Boyesen Rad Valve really revived the engine with the low end power that we were craving. Towards the red line, the two-stroke started to fall flat and forced me to ride it in the meat of the power. In the end, the two-stroke definitely put a smile on my face, but the four-stroke power was easier to handle.
The RM-Z felt bigger in the cockpit and made finding a comfortable position a challenge. This was most noticeable in the rougher sections as I couldn’t get myself in a balanced position to attack the big breaking bumps. However, it still retained its usual feel in the corners and allowed me to glide through ruts with ease.
The RM also felt stretched out, but not nearly as much as the four-stroke. The tighter ergonomics and smaller chassis feel allowed me to transfer my weight more effectively and move up on the seat in the corners. However, the Polisport Restyle Kit makes the shrouds stick out a bit farther than the standard 2005 plastics and gives the RM a wider feeling compared to the RM-Z.
Deciding whether to build a bike or buy a new one is something that will continue to make the motorcycle industry go round. We might be biased, but the overall look of our RM edges out the stock RM-Z. On the other hand, perks of a brand new RM-Z does come with EFI, mapping options, and absolutely zero hours on the components. New Suzuki’s are selling for appealing prices and allows buyers to perform some race ready modifications for less than the out the door price of most other 250F’s.
Both bikes are two fun bikes that don’t break the bank for your average rider. I felt the two-stroke had a slight advantage with all the aftermarket products helping fine tune the bike into something I’d typically ride myself. The four-stoke was bone stock and would need a few key parts to find its true potential. On the stock RM-Z, you lose some excitement in the engine character and have to work attentively to ride it in the meat of the power. On the two-stroke, I felt I could ride it as if it were my own YZ250 with a similar powerband and exciting feel.