In the 2019 250F Shootout, all Vital’s testers (and pretty much all other media outlets) put the Suzuki in last place. Except for me. Call me a contrarian, or just weird, but I have the LITPro data to back it up. I set my fastest lap times on the RM-Z250. Why? For one, I really like the way the Suzuki handles, and, two, the “oversprung” fork matches my weigh and ability perfectly. When you are comfortable on a bike, you go faster. Plain and simple. 

That being said, there are very clear reasons the 2019 RM-Z250 lands behind the rest of the bikes in the class for most riders. The fork is on the stiff side and also has a lot of harshnesses that transfers hard hits and chatter to the rider, no matter what you do with the clickers. The other major problem is power. With other bikes in the class becoming more punchy, quicker-revving and overall more responsive, the Suzuki retains a slightly slower revving, sort of old-school feel that isn’t necessarily slow, just a tick behind the rest of the class. 

Naturally, the first move to was to try to get some more power out of the motor, and there are a few ways to do this. Unfortunately, the list of options for the current Suzuki RM-Z250 is a little limited. But, as always, one of the steadfast and reliable companies to turn to for performance parts is Pro Circuit. While they do have an engine spec for the current RM-Z250, they were confident enough in their exhaust to just send a T-6 Stainless Full Exhaust system and High-Compression Piston to add some power without draining the savings account. 

Starting with just the exhaust, I spent a lot of time on the stock machine and was very familiar with the power. Like I’ve said before, the power has a very “one-note” character. It has a fairly hearty bottom to mid-range hit and falls flat everywhere else. Also, once you are in the meat of the power in the mid, it doesn’t want to change rpm much at all. I would roll on the throttle out of a corner and once the engine would get into the mid, even if I kept opening the throttle more, not much would happen. 

With the T-6 on the Zook, there was a huge difference. For one, it has a smoother, deeper tone that is not any louder than the stock pipe. More volume does not always equal more power, and even for moto bikes, we have to be aware of bikes being too loud. On the track, the power actually feels a tiny bit mellower right off idle, at the very bottom of the power, but the pipe shifted the power a little higher from mid-bottom, through the mid-range and definitely increased the top end. With the stock pipe, the top-end power is pretty much non-existent and the PC pipe didn’t turn the RM-Z250 into a revver. What it did was just wake up the power, shift it up a little bit and give the bike some rpm response in the mid and top. Now, I can be in the meat of the power, give it more throttle and actually have the rpm rise and get more out of the machine when I need it. 

You can see the different shape of the PC head pipe.
Stock vs. PC piston.

After that, I put in the PC High Compression piston which is made by JE Pistons to Pro Circuit’s specifications. With the pipe and piston, the RM-Z got a boost back in the bottom-end to fill out the gap left by the pipe without taking away any of the mid and top-end power. I really liked the way the Suzuki rode with both piston and pipe. Did it make it the fastest 250F out there? I would say no, but it is on its way. An ECU would be the next step but that doesn’t fit in a budget level build. 

We also called on PC’s expertise in the suspension department. While I liked the Suzuki’s fork and shock on a relatively smooth track, when any sort of bumps or roughness started to develop, my opinion of the fork quickly diminished. The stock spring rate for the fork is .51 kg/mm and given my weight of 215, PC decided to bump that up to .54 kg/mm. Now, for a normal weight 250F rider (150-160) .54 kg/mm fork springs would be in the supercross range. 

The Pro Circuit valving was great, we just liked it better with the stock springs back in.
PC nailed it with the shock.

When I got the suspension back and put it on the bike, I noticed immediately that the was too stiff. I did try to get used to it and ride harder, and the harder I pushed, the better the fork worked but I was on the edge of crashing the whole time. Also, PC returns suspension with the clickers adjusted pretty far out. I only had five more clicks of compression adjustment to play with until they were fully soft. I knew that to be comfortable, I’d need the stock springs back in. So that’s just what I did and got the result I was looking for. 

With the stock springs and PC valving, the fork turned out to be pretty much awesome. I set the clickers back to the middle of the adjustment (12 out) and this worked great. Gone was the harshness and reluctance to take sharp impacts, and in its place was comfort and plushness that gave me a ton of confidence in the front. The revalved fork is more comfortable and predictable and stays planted through braking bumps and chatter without trying to dislocate my wrists. 

All graphics should have gold in them! ERA Moto Co. killed it.

The shock, on the other hand, was great with the stiffer spring that PC installed. On the stock shock spring, I was pretty close to maxed out with sag which made the rear of the RM-Z feel too springy and active in some situations. The revalved and resprung shock has a firm planted feeling that is more on the “dead” side of feel, and I could set the sag properly with the correct amount of free sag in the bike. 

Rounding out the build, Renthal gave us some bars, grips, chain, and sprockets to refresh the Suzuki and match the PC team. Along those lines, Hinson sent an ignition and clutch cover, again to give that PC factory team look. ACR Memlon levers are actually some of my favorite feeling levers because they are fatter and rounded on the front. Some riders don’t like how big they are but I find them very comfortable. Since there aren’t green plastic kits for Suzuki’s, I got a white kit from UFO, including handguards and front disc guard. ERA did the graphics and killed with the gold flake in there. Works connection provided some red bling, just like the PC bikes and we spooned on Maxxis Maxxcross MX-ST tires - we’ll have a full test of those coming later on. 

Last Word

Confidence is the key to riding well. On the stock 2019 Suzuki RM-Z250 I had pretty high confidence in the handling and the motor was pretty good. But with the PC suspension, pipe, and piston, my confidence riding this bike has gone way up. I now know that I can charge straight into braking bumps and square edges rather than avoiding them like the plague. I can also make a mistake and the engine will still be able to respond to get me back on track. I would recommend these mods to any RM-Z250 owner who wants a better Suzuki without a heck of a lot of hassle. 

Parts List:

ARC
RC-8 Clutch Perch Assembly, Memlon lever: $194
Brake Lever, Memlon: $69.99

Renthal
Fatbar 672: $91.95
Rear Sprocket: $71.95
Front Sprocket: $26.95
R1 520-120L Chain: $97.95
Grips DL Kevlar: $20.95

UFO
Plastic Kit: $145.99
Chain Guide/Swingarm Slider Kit: $44.99
Fork Guards: $30.99
Front Disc Cover: $64.99
Vulcano Hand Guards: $34.99

Pro Circuit
High Compression Piston: $394
T-6 Stainless System: $818.96
Suspension Revalve and springs: $905.20

Works Connection
Oil Filter Cover: $49.95
Oil Fill Plug: $24.95

ERA Moto Co.
Graphics Kit: $229.99

Maxxis
Maxxcross MX-ST Front: See your local dealer
Maxxcross MX-ST Rear: See your local dealer

Hinson
Billetproof Ignition Cover: $399.99
Billetproof Clutch Cover: $169.99

Total: $3,888.72 (without tires)

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