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

"Best" is strongly dependent on your individual performance specification. Usually people buy an Ignitech DC CDI P2 or a Zeeltronic PDCI. Both are DC CDIs, which means you just need a stable 12V supply and a pickup to operate them. In the US there's a plug & play kit available from Ed ...

That's no rocket science. A few years ago my local tire guy ceased doing motorcycle tires and the remaining rest wanted 30 Eur PER WHEEL just for mounting. And a blow job while waiting was not even included. So I got myself on of those from the local classifieds: https://www.gp503.de/index.php/reife...

Magnets can loose their properties when being exposed too high temperatures. The very strong neodymium magnets are extremely prone to this effect. I have welding fixtures that completely fall off when you leave them on for too long and they catch too much heat. The magnets used in the RD rotor are t...

You guys that run EGT, what is a safe max temp. to avoid metdown Easy answer. It's that temp reading that didn't melt the piston. Or in a more extended version: Depending on the type of sensor, the state of that sensor, the connection cables and the electronics at the very end, you can basically ge...

Nope. Smaller stinger dia increases top performance. Just until the point where it decreases it very suddenly to zero emitting a very disturbing noise... For stock'ish RDs some 20-22 mm is in the ballpark. Higher tuning levels with more performance will require a bigger diameter. I prefer being on t...

Well, it works, but it certainly helps, if you have some dataset to base on. Or a community of users to assist with questions. The good news : There is a couple of examples available in the installation and RZ350/Banshee is one of them. If you have a working dataset, the modifications are easy. You ...

When talking about stock CDI's: Depending on the year, there's basically two wires to check. 31K (83&84) and 1WW (86+) have a black-white cable on the CDI. The ignition switch and the kill switch connect that cable to ground. The harness also has a black-white cable that exits near the CDI. If y...

You plan to use a 26 (25?) mm exhaust port height with a +4 crank. You did not mention whether you used a base spacer or machined the head to have the piston protrude 2 mm. If it's the spacer solution, your exhaust timing is waaaay too high (some 206 deg), especially in combination with higher revvi...

I have no problem with the origin or location of people and usually politics is not an issue here.
RD enthusiasts help fellow enthusiasts - that's more fun.
If I want to get upset, I can still watch the news.

Concerning the ignition I'd recommend to switch to a programmable DC CDI anyway. Why? Because it works with any combination of rotor/stator, replaces the CDI and PV controller at once and adds some decent performance with an invest of some 300 Eur. Check out the electronics chapter of my RD500 manua...

Some of you have a wealth of racing experience with twins and might be able to explain this phenomenon of only one side melting on a twin when the air/oil/ignition is identical for both cylinders. IMHO a good explanation would be crank twist. Each cylinder ist putting torque on your crank which sli...

No need to get triggered and especially no need to insist having the only truth especially when it's pretty outside everyone else's experience. Running WOT is not the most critical state as the fuel cools quite a lot when vaporizing. You can imagine that road bikes run over a wide range of throttle ...

FYI: Yamaha OEM 48H specs say BR9 for high speed riding https://www.rd350lc.net/specRZUSchass1.jpg European past 1986 models say BR9 for all models, except the restricted 27HP 1WX https://www.rd350lc.net/spec-86chass1.JPG The earlyer 31K actually had a BR8 recommendation, but that's for stock bikes ...

I'll revise the "low on oil" hypothesis, too, after having seen the piston crown.
This clearly cries too hot plug.

A BR8 is too hot for any extended period of WOT operation. Use 9 and you're fine. Also an AFR of 13 may be good for performance but remember that fuel is also used for cooling. I run something like 12-12.5 in the WOT and high rpm range. Check EGT to stay on the safe side. But your piston does not lo...