Rider: Trent Pugmire
Bike: 2008 Honda CRF450
Location: Glen Helen Raceway
Date: May 29, 2014
Photographer: John Basher
Camera: Canon 1D Mark III
Lens: 300mm f/2.8 IS-2
Focal length: 300mm
Exposure: 1/1250 sec.
F-stop: 5.0
ISO: 200



“It was tough, and I don’t really think that anyone around me thought that I was going to make the start of the season, but I was very determined to make it to the opener. I remember one time back then when my trainer, Ryan, and I were mountain biking. He was yelling at me, and I was sitting there with tears streaming down my face thinking that I was not going to make Supercross happen. From that point on it was like a light switch went on. I put my heart and soul into getting ready.”

Click here to read the interview.


Well, folks, it’s finally done. You’ve followed me on this long journey to two-stroke bliss. Minus a few components, my 2005 Yamaha YZ125 is a great example of what can be done with vision and deep pockets. I won’t try to pull the wool over your eyes, though. Thanks to a bunch of great companies/loyal advertisers, I didn’t go broke building my dream YZ125.

This is the third straight year I built a Yamaha YZ125 project bike. The first year was a learning experience. Up until that time I didn’t pay much attention to 125cc two-strokes. I frequently raced, so bikes like the Kawasaki KX450F and Yamaha YZ250F usually accompanied me to the track. However, I had a few kids and put racing on the back-burner. By happenstance I jumped on a YZ125 to race the 125 Two-Stroke Adult class at REM with my buddy, Scott “Whisky” Williams, just for fun. It was love at first crack of the throttle (the YZ125, not my feelings toward Scott).

I’m not going to try and convince you that keeping the stock YZ125 compression is the best way to go, but it works for me. Add a pipe, silencer, aftermarket reed valve and new top-end kit and I’m happy as pie. 

Why do I love the Yamaha YZ125? Let me count the ways.

(1) It’s bulletproof. I haven’t encountered many mechanical issues with the bike, aside from normal wear and tear.
(2) It has a six-speed transmission. Rarely do I use first or sixth gear, but the close-ratio transmission means I always have a bit of leeway if I flub a berm. For that reason the YZ125 is very forgiving.
(3) It has awesome suspension, notably on the 2006 and newer model. The Kayaba SSS components are the perfect blend of performance and bottoming resistance. I’ve tested many bikes that are good in one area but sacrifice in another part of the track. Not the SSS-equipped YZ125.
(4) It’s a breeze to work on. I can reach the piston by only using a few metric wrenches, Philips head screwdriver, and a couple Allen wrenches. The parts are also relatively inexpensive to replace (unless you go the expensive route like I did).
(5) It doesn’t do anything glaringly wrong. That says a lot about a bike, given that you often have to give to get. The suspension is great, the engine is solid from the bottom to top, and handling is neutral. It’s baby bear’s porridge, plain and simple.

The only stock parts in this picture are the pinch bolts, fork guard bolts, front brake pads and front brake caliper. 

Having said those things, I unloaded every idea I could possibly think of into my 2005 Yamaha YZ125. Why? I suppose it’s a sickness. If some changes are good, then more must be better, right? We’ll see. As overboard as I did go, it could have been a whole lot worse. I almost pulled the trigger on titanium hardware and, if CRM in Italy ever emailed back about purchasing a carbon fiber fuel tank, I would have been in way over my head. However, I’m a believer that things work out as they’re supposed to. As is, my YZ125 has Kayaba PSF-1 A-Kit suspension, a full Hinson Billetproof clutch, X-Trig adjustable offset triple clamps, Dubya wheels with D.I.D. DirtStar rims and Talon magnesium hubs, Pro Circuit Works pipe with carbon fiber silencer, Pro Pegs titanium footpegs (with titanium pivot pins), ICW reinforced radiators, Moto-Master brakes, LightSpeed carbon fiber parts, a full Cycra Racing restyled plastics kit and DeCal Works semi-custom graphics. Like I said, the build was far beyond the realm of normal. I’m not ashamed, though. For the past 12 years I’ve learned the project bike craft and wanted to showcase my knowledge by unleashing a bike that would be admired and desired by many. Hopefully you’re in that club.

It pays to have good friends. Brett Koufas from ICW gave me the carbon fiber ignition cover from a company in Italy. There are also titanium footpeg pivot pins from my buddy, Mark “Chillzone” Chilson. 

Want to know some interesting tidbits of information I learned while building the 2005 Yamaha YZ125 project bike? Read on.

(1) The Kayaba PSF-1 A-Kit air forks use the newer fork lugs, meaning that I had to get different front wheel spacers and a shorter axle to fit the forks. I also used Cycra front fork guards. I’m a nut (no pun intended) about keeping extra nuts and bolts leftover from old project bikes. Fortunately I had six bolts that fit perfectly in the fork guard holes. You’ll probably want to know that a different front brake hanger was also necessary. Moto-Master took care of that.
(2) X-Trig makes a crazy set of ROCS triple clamps. I’ve ridden with them before, but never installed a set. The technology is unbelievable. I swear a group of NASA scientists created the blueprints for the ROCS system. The YZ125 clamps have an adjustable offset–22mm or 25mm–and use four different torque settings for installation. I like that X-Trig includes bar mount risers. I didn’t use them, but I like how they were included. I’m 6’1” when my lower back allows me to stand up straight, but I’m not exactly Andre the Giant. Hence, the standard bar mount height works well.
(3) I could have begged a newer airbox out of Yamaha–and they likely would have obliged, given they shipped me a new subframe–but I don’t mind the look of the older airbox. The newer integrated airbox/side panel design doesn’t look as racy to me as being able to see the midpipe and more of the subframe. Maybe that makes me old school.
(4) Don’t think for one second that I completely overhauled the engine. I didn’t. I’ve tested YZ144’s before, and I didn’t like how the big-bore changed the powerband. To me, going oversize turned the stock stud into a dud. Instead I installed a Vertex top-end kit and focused on what I knew would work. Which brings me to…
(5) I’ve had really good results with the Boyesen RAD Valve on the YZ125. It sharpens throttle response and increases power across the board. For good measure I threw in a Boyesen Power X-Wing, which is said to better direct airflow into the carburetor. Those changes, combined with a Pro Circuit Works pipe and Shortly carbon fiber silencer, turns the YZ125 into a rocket ship.
(6) Laugh if you want, but I went up one tooth on the rear sprocket. MXA gets a bad rap for always insisting on gearing test bikes down. That’s not true. Manufacturers have begun embracing the idea that motocross riders–not desert dogs–are buying motocross bikes. Hence, manufacturers are now gearing their bikes (there I go again with the puns) toward moto-minded riders. As for why I went up to a 49-tooth rear sprocket, it makes the shift from second to third to fourth gear much easier. I’m too slow and too heavy to keep the power on the pipe otherwise.   

Tomorrow I’ll take the bike on her maiden voyage at ClubMX Practice Facility. It will be ridden by Ben Graves (ClubMX Practice Facility manager), Jessica Patterson (multi-time Women’s National Champion), Allan Brown (former Moto XXX team owner and Star Racing team manager) and myself. Look for an opinion piece on the bike in next week’s Mid-Week Report.

Pro Circuit makes a Kevlar Ti-2 silencer that’s $329.95. Is it worth that much? It all depends. I wouldn’t go any other way.

The KYB A-Kit shock has high- and low-speed compression, as well as high- and low-speed rebound settings.
A blend of old and new. LightSpeed provided the necessary carbon fiber guards to ensure the vital organs of the YZ125 are safe from impact.

Yes, that’s a stock 2005 YZ125 radiator. ICW essentially made the radiators crush proof by adding bracing.

Sunstar sprockets and chain are responsible for putting power to the rear wheel. One tooth was added to the rear sprocket. 


Remember when Chad Reed rode for factory Yamaha (the first time) way back in 2005? This photo was taken of the Australian at his outdoor track in Florida during the 2005 Supercross series. He was testing for the Nationals during a rainy day leading up to Daytona. Reed spun laps with then teammate, Tim Ferry. By the way, I’m pretty sure this photo was taken in March of ’05, but maybe it was from 2006. The years blend together.


Pro Circuit has a catalogue of jetting specs–stock, as well as the Pro Circuit recommended jetting–for carbureted bikes going all of the way back to 1984. This is a handy tool that makes a lot of sense. Note that Pro Circuit recommends running 32:1 pre-mix ratio with Maxima Castor 927 oil for two-strokes. The four-stroke settings are dialed in for premium pump gas at 0-1500 foot altitude from 70-85 degrees Fahrenheit.

Click here to view Pro Circuit’s jetting catalogue.


Check out James Stewart’s digs


Torsten Hallman was credited with being one of the first men to introduce motocross to the United States. The four-time World Champion was brought over to America by Husqvarna importer, Edison Dye, to showcase the brand’s superiority in motocross. That was accomplished by Hallman waxing America’s best scrambles riders at events, such as the prestigious Hopetown GP in SoCal.

The classic photo above shows Hallman soaring through the air on his Husqvarna 250 Cross. Notice the pudding bowl helmet, crude motocross gloves, all-leather pants and lack of eye protection. You can read about Torsten Hallman’s exploits and impact on motocross by clicking here.



An ongoing list of the top qualifiers and holeshot winners from each round of the 2016 Lucas Oil AMA 250/450 Nationals.


Hangtown…Eli Tomac


Hangtown…Joey Savatgy


Hangtown…Cole Seely / Ryan Dungey


Hangtown…Joey Savatgy / Jessy Nelson

chad reedhangtown nationalJOHN BASHERMID-WEEK REPORTpro taperTorsten Hallmantrent pugmirewhipitwednesdayYAMAHA YZ125