RZ/RD 350 & Misc. 2-Stroke Tech BBS

The Pro’s and Con’s of installing a smaller, lighter rear tire, Pro’s If I pick an average 1/4 mile time is 12.5 seconds and an acceleration increase of 5%, and then apply simple Drag Race math, (which is based on hunches, assumptions, and wishful thinking, and has nothing to do with physics or calc...

By this time, I had pretty much abandoned any thoughts of working on the bike, and I still had some unanswered questions, so the search continued. Hey Google, how does Tire Diameter affect Torque? The short answer, it doesn’t. Torque is produced by the engine and transmitted through the front sprock...

I returned to the shop with a new point of view and some new questions. What are the downsides to a smaller tire? And as always, there was the big question; How Much ? A new tire will cost $180, and another $75 for some longer dog-bones. Better make that $150 for dog-bones, because I’d get 2 sets wi...

So, can I make it lower? Well, maybe. A lot of racers use tie-down straps, (connected between the triple tree and lower fork leg), to compress the forks. It’s a simple way to lower the front end, and it’s not terribly expensive. And I like modifications that are easy and cheap, because I’m lazy and ...

At the last race in 2023, the RZ had an intake leak, and I tried to fix it using high temp RTV. Not one of my better ideas. I hadn’t touched the bike since the race, so it was still sitting in the garage with 1/8” of orange silicone smeared all over the intake rubbers, reed blocks, and the intake ma...

As I’ve previously said, Bracket Racing has nothing to do with how fast your bike will cover the 1/4 mile. It’s all about consistency. All your runs down the track need to be the same, +/- a few hundredths of a second. During Qualifying, you want to find out how fast the bike will run on that day, a...

Hey folks. It’s been a while since I posted because, I didn’t have anything to say. I hope everyone is still safe and well. I wrote the following 7 part novel back in February, and then sh*t happened, life got busy, and I forgot all about it. It’s a bit outdated, and as always, a tad long winded, bu...

Thanks to Jon and Waltmilt for your input. You guys are correct. I have also heard that idiom and have had it happen to me personally. So, after running this motor for 8000 miles on the street, and then making over 200 runs down the track, the compression dropped 1 psi on the Left cylinder, and 3 ps...

It was a long, rather somber trip home, and I had plenty of time to reflect on the past race season. I assumed that I didn’t hurt the motor. And I assumed that the RZ had a charging issue. After getting the RZ back to the shop and charging the battery, I started the bike and discovered that the cha...

Thanks to Ken and Jon, and the other folks out there, for following along on the adventure. It was a somewhat disappointing season, because I’m pretty competitive, maybe overly competitive. When I enter a competition, I want to win, and show everyone that I can do this better than them. I have no pr...

Crank winding is when the ignition timing on the right cylinder is firing to early due to there being a delay induced by crank twist under load. Hi Kenny. Thanks for the information. I'm running the Zeeltronic PDCI-D22 race ignition and it does not allow me to advance or retard idividual cylinders ...

It was a long, rather somber trip home, and I had plenty of time to reflect on the past race season. I’ll give you the quick recap, and then I’ll stfu, and quit wasting your time. I assumed that I didn’t hurt the motor. And I assumed that the RZ had a charging issue. I was upset that, for the first ...

After showing my time slip to everybody within shouting distance, I put 3 liters of fuel in the bike, so that it was ready for the Elimination rounds. Then I sat down in the shade, and went back to the task of picking a Dial-in Time. And this last run was not as helpful as I had hoped it would be. O...

While I was thinking about the dilemma, I heard the track officials call all bikes to the staging lanes, for an open Test and Tune session. When I heard the announcement, I was confused, because the bikes only had 1 Test and Tune scheduled, and I had already participated. As I thought about it, it o...

So, getting back to where I was, evaluating my runs and picking a Dial-in Time. I made 4 decent/average runs, and had times of 12.62, 12.68, 12.73, and 12.62 seconds. My 2 quickest times were in the morning, and early afternoon. My 2 slowest times were in the late afternoon, when the air was hotter....