MXA’S WORLD TWO-STROKE CHAMPIONSHIP HUSQVARNA TC300 PROJECT RACER
The World Two-Stroke Championship is sponsored by Wiseco and Fasthouse. Every year the MXA test riders make plans to have a fun day at Glen Helen blasting around in a pack of smokers. Each and every MXA test rider approaches the World Two-Stroke differently; some choose to race a box-stock Husqvarna TC250, KTM 250SX or Yamaha YZ250, others don’t sweat the details and race production 125s for the thrill of it, while a handful have rebuilt Honda or Suzuki two-strokes from the past. As with all two-stroke races, the bikes represent a potpourri of models, brands and conditions. But, there is one group of MXA test riders who are super serious about their World Two-Stroke mounts. They want the newest, fastest, trickest race bikes possible—and spend months lining up engine builders, suspension components, custom graphics and their personal must-haves for the once-a-year event. They are the Pros.
Heading into the 2020 MTA World Two-Stroke Championship, which has been delayed by the Covid-19 virus from April to June and now to October, the MXA wrecking crew has seven test riders, including in-house testers, photo testers and endurance testers, who want to race the two-stroke event. No big deal. This is the normal number of test riders that we use on a regular race weekend, but we only had six 2020 two-strokes. Again, this is also not unusual. We often have two or more test riders race the same bike on the same weekend in different classes; it speeds up the testing process.
As a rule, MXA honors all of its test riders’ two-stroke demands (based on a simple hierarchy) to ensure that no one is left out. We promise our Pro test riders first pick, with a codicil that they do not have to share their bikes with anyone else. Dennis Stapleton is very high on the priority list, and we told him to pick whatever bike he wanted to race, but he didn’t want to pick first, so with the help of Husqvarna, he got a second 2020 Husky TC250 two-stroke, freeing up our original TC250 for someone else.
Which brings us to MXA’s World Two-Stroke Championship 2020 Husqvarna TC300 Project Racer as envisioned by Husqvarna, the Rockstar team and Dennis Stapleton. Size matters in the Pro class at the World Two-Stroke race. The 125 class is open to 150cc engines, and there are no limits on how big an engine can be in the premier Open Pro class. Although a quorum of the Pros line up on 250cc production bikes, there are a healthy number of 300s, 325s and 500s.
Given Glen Helen’s 70-mph start and big hills, there is no replacement for displacement. It can get you to the front—although no one on a 500 has ever managed to stay in front long enough to win the Open Pro class. The meat-and-potatoes Pro bike is a kitted 250, bumped up to 300cc, which is exactly what Dennis decided to do to the 2020 Husqvarna TC250. It is important to note that neither Husqvarna nor KTM manufactures a 300cc motocross bike, but they understand the power of cubic centimeters and offer 300cc kits.
INSIDE DENNIS STAPLETON’S WORLD TWO-STROKE ROCKSTAR HUSQVARNA TC300
We’ll let Dennis take it from here: “My bike of choice was the Husqvarna TC250,” said Dennis. “As an MXA test editor, I have a lot of experience jumping from one brand to the next, sometimes between motos. That experience makes it much easier to go cold turkey onto a bike that I have ridden, but not raced this season. I knew from a few test sessions, video shoots and playing around that there would be minor issues, but I had raced MXA’s KTM 250SX and done more than enough test hours in the saddle of the orange bike to know that a Husky version would be more than capable of running up front. Here is the list of the things I did to MXA’s 2020 Husqvarna TC250 for the World Two-Stroke race.”
Engine: “Normally, I would have pressed Pro Circuit’s Mitch Payton to build my TC250 engine, but Husqvarna’s Andy Jefferson said that he would get me Jason Anderson’s Factory Service two-stroke top-end. It had been built for Jason to use at the Red Bull Straight Rhythm event, but he chose to sit the race out, so the complete top-end was just sitting on a shelf. Even though Factory Services is the race-engine arm of the Red Bull KTM Factory and Rockstar Husqvarna Factory teams, they don’t specialize in two-strokes. Fortunately, Factory Services’ Dudley Cramond has been in the race world long enough to know more than a little about two-strokes and how to make them fast.
“The top-end Factory Services gave me was already equipped with a Husky Power Parts 300cc upgrade kit, which includes the cylinder, head, piston, rings, wrist pin, clips, power valve, gaskets and black box. It is a simple bolt-on kit that produces a broad style of power that makes the 300 easier to ride than the 250. On the dyno, a kitted Husky TC300 pumps out 53.32 horsepower to the TC250’s 49.23.
“But, there was nothing stock about Anderson’s top-end. It had been massaged by Dudley, which included placing a spacer plate under the cylinder to raise the ports, where they could be manipulated down. To raise the cylinder, the head had to be machined and re-chambered to make room for the piston. To keep Jason Anderson’s Rockstar setup, we ran VP MRX02 fuel, a Moto Tassinari VForce4R reed cage, an FMF Factory Fatty exhaust pipe and FMF Titanium Powercore 2.1 silencer.”
Forks: “For the forks, I planned to run a brand-new, re-valved set of WP XACT Pro Component forks, better known as Cone Valves. These are the exact forks that I run on my normal KTM 450SXF race bikes. I trust them, and I trust the staff at WP Components in Temecula to give me what I want. Unfortunately, when the coronavirus hit, WP closed its shop and my World Two-Stroke Championship forks were on lockdown. To get some testing done, I swapped the forks off my KTM 450SXF onto the Husqvarna TC300. They were firm, but the more I rode with them, the more I realized that maybe I had been going too soft in previous years. To tell the truth, I wouldn’t choose anything other than a set of Cone Valve forks for my Husky or KTM.
Shock: “I ran the same valving in the WP Pro Component Trax shock as in my 450SXF. I was comfortable with that shock and felt that by turning the shock’s and fork’s compression out 4 clicks and the shock’s high-speed compression out 2 clicks softer, I could lessen any squatting of the rear end under the brutal two-stroke acceleration. The stock 2020 Husqvarna 250 shock spring is 42 N/mm, but I felt that a 45 N/mm was going to be needed for Glen Helen’s high speeds and big hills.”
Factory triple clamps: “These are the triple clamps that come on the 2020-1/2 FC450 Rockstar Edition. I like them over the stock triple clamps. They really help with the hand feel at the bars, especially at steep lean angles. The lower-clamp torque settings are 12 N/mm and the upper torque settings are 17 N/mm. I run 18.5 N/mm because the forks are prone to creeping upwards. You don’t have to buy a Rockstar Edition to get the clamps. Your local Husky dealer can order the Factory triple clamps for you.”
Factory wheels: “The Factory wheels are not just anodized stockers. These wheels come with all-new stronger hubs and blue anodizing, and the front wheel is laced with a cross-three spoke pattern.”
Footpegs: “MetalTek made me custom footpegs by milling off the top of the stock pegs and welding on a new set of teeth. They can modify your stock pegs for $150. MetalTek offers many configurations, but I run the outside four teeth a little taller to help keep my feet tucked in.”
Handlebars: “I like the stock OEM Pro Taper bars on the Husky TC250, and I don’t move them very far off of the neutral position. I added ODI’s soft gray grips. The only thing I did with the controls was to rotate the throttle housing slightly forward to lessen elbow drop. Of course, I tightened up the throttle cable to remove any excess slack. I ran my front brake lever close to the grip compared to where I run it on a four-stroke. Without any decompression braking from the two-stroke engine, I want to get to the lever quicker to make brake dragging easier through the center of turns. I run my Magura clutch lever a little bit more extended so that I can find the release point off the gate. I don’t do this with the Brembo clutch lever on my 450SX, because it has the ‘pop’ feel that I like while the Magura feel is more linear and smooth. Since I was running Pro Taper bars, I elected to add a Pro Taper Pro Series chain and sprockets.”
Rear tire: “I went against the grain with my tire choice for the World Two-Stroke track. I chose to run a 110/90-19 Dunlop MX53 rear tire. It’s a strange choice, because Glen Helen has the kind of dirt that is better suited to a pure intermediate-terrain tire, such as the MX33, but I went with this tire because I like that it breaks traction a little easier than the MX33, which helps me keep the power in the sweet spot of the rpm range. I chose a 110 rear because it rolls over from center out better than a 120. The 120 is good for straight-line traction, but the 110 is better in corners and ruts. By the time the Open Pro class rolls around at the World Two-Stroke Championship, the track is beat up and littered with square-edge bumps, which is why I elected to run a hard-pack tire. I have spare wheels with MX33s in the van just in case.”
Front tire: “Although I’m tempted to go with a Dunlop MX53 front (depending on how hard the dirt is on race day), I will likely run an MX33, because the MX53 can be very sketchy on tracks with loose dirt on top of hard-pack. So, the choice between the 33 is a better overall choice. If the track dries out and the corners are baked enough for the hard-pack front tire to work, then I’ll go with an MX53.”
Miscellaneous: “The gray plastic came from Acerbis, while the Rockstar Energy Husqvarna graphics were made by Factory Effex. I opted for bright-yellow number plate backgrounds to pop off of the gray plastic and to highlight the yellow Rockstar Energy logo. The seat was from Guts and came with the soft foam that Jason Anderson likes. The cut-down carbon fiber skid plate was just big enough to go from frame rail to frame rail with no water pump or ignition cover extension (it came from the Rockstar Energy team). The brake rotors were a stock 260mm front and 220mm rear. Don’t let the Rekluse clutch cover fool you. The clutch was a stock diaphragm clutch. It was bulletproof. I have a WP holeshot device on the forks, but I’m thinking of running a second one, with one at 100mm and a second one higher to pull the forks down farther if the start line is tacky.”
RIDING DENNIS STAPLETON’S WORLD TWO-STROKE ROCKSTAR HUSQVARNA TC300
“With the coronavirus delaying the complete 2020 race season, there is no telling when the 2020 Wiseco/Fasthouse World Two-Stroke Championship will be held, but I plan to be ready when the day rolls around. My race bike is perhaps one of the easiest pre-race builds I ever had to worry about. With the help of Husqvarna, Factory Services, Husqvarna Power Parts and the Rockstar Husqvarna race team, I didn’t have to chase down parts all around SoCal. Most of the stuff I needed was available in Temecula, California, on the corner of Technology Drive and Innovation Court, where Husqvarna is located, along with WP, Twisted Development, Factory Services, KTM and Rocky Mountain KTM. Best of all, at the junction of these two streets is where I got my engine, suspension, wheels and triple clamps. If you are nowhere near where these two aptly named streets meet, you can order all the parts, save for the virtually secret top-end work, from your friendly local Husqvarna dealer.
“All that was left, apart from waiting for the World Two-Stroke Championship to find a solid date, was to break the bike in, fiddle with the suspension, spend some time adjusting to it, let the other MXA test riders give me feedback and make a list of the things that I might want Husqvarna to change for me. I can’t complain about the WP Pro Cone Valve forks and Trax shock, because they were set up to the specs that I had developed over the last year.
“First of all, I love Dudley’s engine. It has that snappy feel right off of idle that I expect from a two-stroke. At first I thought it was a little too much, but in the transition into the midrange it smoothed out. It pulled hard. It preferred to be ridden hard in third gear, as second gear was a little jumpy, but nothing that couldn’t be fixed with one less tooth on the rear.
“Most noticeable was that Jason Anderson’s top-end had a freer-revving feel on top than all of the other 300cc KTMs and Huskys that I’ve ridden. This is most likely a combination of mapping, which Factory Services didn’t want to reveal, and the cylinder mods that they only revealed under pressure. It didn’t rev all that much higher than a stock TC250, but it did it with full-bodied gusto. With VP Racing MRX02 fuel in the tank, the effect on the 300cc engine was an added dose of energy. We didn’t have to rejet, because Dudley and the Rockstar guys had already figured that out for us.
“I prefer the 300 engine kit to the stock TC250 mill. You might think I chose the 300 because it makes a lot more horsepower at every step along the curve, but that isn’t it. What I like best about the 300 is that it is easier to ride. The added power fills in the powerband so that you have throttle solutions for every situation.
Whereas four-stroke handling is taut, two-stroke handling is loose. The FC450 four-stroke is a front-end handler that tacks the front wheel to the ground and then drives it through the corners. The TC250 two-stroke is a rear-wheel handler. The front end isn’t tacked to the ground; it is floating unless pushed into the ground. Turn initiation is typically off the rear wheel, not the front wheel. While hard-hitting two-strokes are a blast to ride, a broader powerband with less liftoff makes for a better race engine, which is why flywheel weights help 250 two-strokes cut faster lap times. With the 300 kit, you don’t need a flywheel weight, because the extra power isn’t scary fast. It is super usable.
“Now, all I have to do is get a good start and let all the goodness come to the surface.”
HUSQVARNA TC300 PRICE LIST
Husqvarna/KTM 300 engine kit: $956.9
FMF Factory Fatty pipe: $259.99
FMF Titan Powercore 2.1 silencer: $399.99
WP Pro Components Cone Valve forks: $4250.00
WP Pro Component Trax shock: $2535.74
Factory triple clamps: $623.99
Factory rear wheel: $424.95
Factory front wheel: $499.95
Pro Taper Pro Series chain: $129.99
Pro Taper OEM handlebars: $129.95
Acerbis gray plastic: $159.95
Factory Effex graphics kit: $249.95
Guts seat cover: $69.95
MetalTek footpegs: $150.00
Moto Tassinari V-Force4R: $168.00
ODI Lock-on grips: $29.95
Rekluse clutch cover: $169.00
Dunlop MX53 front tire: $112.98
Dunlop MX53 rear tire: $133.35