Two Enthusiasts Build a Two-Stroke Rocket
Yamaha changed the game when it released the RD250 models in the early 1970s. They were lightweight, fast, and sounded amazing. Maybe you were there firsthand, but if not, you probably heard stories growing up about Yamaha’s racing dominance at that time. Does the name Kenny Roberts ring a bell?
This particular 1975 RD250 was a dream build for two motorcycle enthusiasts who are nearly thirty-five years apart in age. Greg Mazza started riding when he was twelve years old and had collected over eighty motorcycles at one point. Now retired, he teamed up with another gearhead, Tom Pecharka, who is no stranger to vintage motorcycles, especially the Yamaha RD models. The duo set out on a goal to build a unique drag bike and win a local race. The results were better than they could have imagined, and the friendship sparked a revived passion for the sport.
Can you both give a brief background on your interest in the Yamaha RD and how you met for this project?
Greg Mazza: A long time ago, back in the 1970s, these bikes were becoming popular. The two-stroke, two-cylinder motors were winning everywhere–not just in drag racing but road racing, too. I got really hooked on them and figured that I’d build an RD dragster at some point. I met Tom by chance, and now, I’m preaching to the choir. He’s a Yamaha RD fanatic and has every model and part to build one. I’m a long-time motorcycle builder and retired toolmaker. We combined our ideas to come up with what we have here.
Tom Pecharka: I had never done drag racing before but was set up selling vintage motorcycle parts at the Quaker City Drag Strip, which is where I first met Greg. He built a Honda CB750 dragster in the 90s and asked if I wanted to run it at the event; which we did the next year, and the bike did well on the run. The vendors there organize a “gentlemen’s race” that’s 250cc or less, so we figured why not do an RD250 and attempt to wipe the floor? That’s how this bike was born. We won that race by almost a full second.
Greg Mazza: A long time ago, back in the 1970s, these bikes were becoming popular. The two-stroke, two-cylinder motors were winning everywhere–not just in drag racing but road racing, too. I got really hooked on them and figured that I’d build an RD dragster at some point. I met Tom by chance, and now, I’m preaching to the choir. He’s a Yamaha RD fanatic and has every model and part to build one. I’m a long-time motorcycle builder and retired toolmaker. We combined our ideas to come up with what we have here.
Tom Pecharka: I had never done drag racing before but was set up selling vintage motorcycle parts at the Quaker City Drag Strip, which is where I first met Greg. He built a Honda CB750 dragster in the 90s and asked if I wanted to run it at the event; which we did the next year, and the bike did well on the run. The vendors there organize a “gentlemen’s race” that’s 250cc or less, so we figured why not do an RD250 and attempt to wipe the floor? That’s how this bike was born. We won that race by almost a full second.
How did the build process go?
Mazza: We started with a bare stock frame and started cutting and chopping. Tom lives in Canonsburg, and I live in Erie. We sent nearly 2,300 photos back and forth in the process. Because I’m up there, I built the majority of the chassis in my shop while Tom was building the majority of the motor in Canonsburg. We were able to marry them together before the gentlemen’s race last August at Quaker City. We literally got it running the week before the race. My main priority was to see him go down the track and come back in one piece. We built this together and built it to be strong.
Pecharka: There was so much back and forth. I bought multiple full bikes just to get a few parts. The cradle is a stock frame, but the rest is new fabrication. It’s a stock rear hub that was lightened by machining down the center cooling fins. The center of the hub, brake plate, and sprocket carrier were drilled out. That’s a 2.5-inch wide aluminum 18-inch rear rim with spikes in the beads to keep it from spinning. We’re using a highly modified enduro front end from a Kawasaki KS125. It had a 21-inch wheel, but we swapped that with this high shouldered 1.60x18-inch rim.
Mazza: We started with a bare stock frame and started cutting and chopping. Tom lives in Canonsburg, and I live in Erie. We sent nearly 2,300 photos back and forth in the process. Because I’m up there, I built the majority of the chassis in my shop while Tom was building the majority of the motor in Canonsburg. We were able to marry them together before the gentlemen’s race last August at Quaker City. We literally got it running the week before the race. My main priority was to see him go down the track and come back in one piece. We built this together and built it to be strong.
Pecharka: There was so much back and forth. I bought multiple full bikes just to get a few parts. The cradle is a stock frame, but the rest is new fabrication. It’s a stock rear hub that was lightened by machining down the center cooling fins. The center of the hub, brake plate, and sprocket carrier were drilled out. That’s a 2.5-inch wide aluminum 18-inch rear rim with spikes in the beads to keep it from spinning. We’re using a highly modified enduro front end from a Kawasaki KS125. It had a 21-inch wheel, but we swapped that with this high shouldered 1.60x18-inch rim.
What other work was involved?
Pecharka: There are all kinds of hand-made parts on this. Greg modified a generic oil catch can from a car to use as a temporary fuel tank, but we ended up keeping it after testing the rider position. It was perfect. We bored the top of the bottle out and welded bungs in. The wheelbase is 65 inches, which is a foot over stock. The rear fender is a Triumph front fender that we used for the old-school look. I found those original British-made clip-ons that racers would’ve run back in the mid-70s.
The expansion chambers are modified RZ350 units that we removed the mufflers, added stingers, and tucked up in. We used Yamaha Banshee carburetors, intakes, and two stage reeds.
This was a bit of a budget build, with the most expensive parts being the new RD250LC pistons. We didn’t use head gaskets. Instead, we cut grooves and used high-temperature o-rings. The heads were centered and pinned, so they’ll always be perfectly aligned and will have the same performance.
Pecharka: There are all kinds of hand-made parts on this. Greg modified a generic oil catch can from a car to use as a temporary fuel tank, but we ended up keeping it after testing the rider position. It was perfect. We bored the top of the bottle out and welded bungs in. The wheelbase is 65 inches, which is a foot over stock. The rear fender is a Triumph front fender that we used for the old-school look. I found those original British-made clip-ons that racers would’ve run back in the mid-70s.
The expansion chambers are modified RZ350 units that we removed the mufflers, added stingers, and tucked up in. We used Yamaha Banshee carburetors, intakes, and two stage reeds.
This was a bit of a budget build, with the most expensive parts being the new RD250LC pistons. We didn’t use head gaskets. Instead, we cut grooves and used high-temperature o-rings. The heads were centered and pinned, so they’ll always be perfectly aligned and will have the same performance.
What attracts you to two-strokes?
Pecharka: The sound.
Mazza: I like all motorcycles, but I love this particular engine. The RD series, whether the 250s, 350s, or even the 400s, are both good-looking and exceptional performers. Here we are, fifty years after the inception of it, and we’re winning races with it. Tom loves them, so now I have a comrade that’s into it.
Pecharka: The sound.
Mazza: I like all motorcycles, but I love this particular engine. The RD series, whether the 250s, 350s, or even the 400s, are both good-looking and exceptional performers. Here we are, fifty years after the inception of it, and we’re winning races with it. Tom loves them, so now I have a comrade that’s into it.
What is it like drag racing?
Pecharka: I’ve been riding my whole life, but this was a lot different due to the rider position. People always ask how to sit on it, but you don’t really sit on it. You’re basically laying on the gas tank, but because we built it for me, it fits really well. When I go down the track, there’s no fumbling to do anything. We reversed the shift pattern, too, so it’s all down. It’s very quick that way. The bike broke into the 14s and was almost up to 90mph at the first race.
Pecharka: I’ve been riding my whole life, but this was a lot different due to the rider position. People always ask how to sit on it, but you don’t really sit on it. You’re basically laying on the gas tank, but because we built it for me, it fits really well. When I go down the track, there’s no fumbling to do anything. We reversed the shift pattern, too, so it’s all down. It’s very quick that way. The bike broke into the 14s and was almost up to 90mph at the first race.
How did it feel to finish the build?
Mazza: It was a lot of fun and fulfilled a dream. The best part is that it went down the track straight the first time. It stopped well and didn’t have any issues. I got to build the bike I always wanted to build, and it’s good to do it with someone I’m very close to and have a lot of respect for who happens to be thirty-five years younger than me. It’s usually just me doing it, but it’s good to have a partner. It makes me excited about the future and gives a little fire to an old guy who has all of this knowledge and wants to use it. Tom’s a perfectionist and he does things right.
Mazza: It was a lot of fun and fulfilled a dream. The best part is that it went down the track straight the first time. It stopped well and didn’t have any issues. I got to build the bike I always wanted to build, and it’s good to do it with someone I’m very close to and have a lot of respect for who happens to be thirty-five years younger than me. It’s usually just me doing it, but it’s good to have a partner. It makes me excited about the future and gives a little fire to an old guy who has all of this knowledge and wants to use it. Tom’s a perfectionist and he does things right.
