spockets, day dreaming, 2 cycle power and mega squirt?: Off-topic discussion forum: Grassroots Motorsports Magazine

Subscribe get a full year for only $23.95 Sample Free Test Drive—no strings attached

Oct. 9, 2008 10:47 p.m. HappyAndy New Reader

I 've been day dreaming about what my next street bike will be, this is just a day dream, I honestly can't see myself getting another road only bike for a long time into the future. Any way, I realy loved my Yamaha RD 400, and even though I have ridden many cutting edge modern sport bikes, my heart still pines for 70's vintage 2 cycle road bikes. I think I was addicted to 2 cycle oil smoke at one point.

So in my day dream I build a custom bike using a 70's vintage Yamaha RD 400 engine (or possibly a suzuki triple) and a modern ducati monster-esque steel tube frame and modern forks, but I keep the RD's mag wheels. The over all look of the bike is a blend of the best parts of 70's japanese cafe bikes and modern "street-fighters", and since it has 2 cycle power, a bit of moto GP styling too.

Although its not completly nessary, since since theses engines already rip, I was wondering if these engines could be fuel injected to bring the most modern performance enhancements possible. Will mega-squirt work with a 2 cycle? I think that the oil soot would probably foul an o2 sensor quickly, but can m-s run in open loop with out an o2 sensor and still work properly?
Oct. 10, 2008 12:38 a.m. MitchellC Reader

I was just searching around the other day for two-stroke applications for MS. One of the links I found was a guy using megasquirt on his rz350. Here's the link. From his parts breakdown, it was over $600 altogether. I can't remember if the RD400's came with CDI ignitions from the factory, but I know that RD350's used points. The electrical system on these old bikes aren't very sophisticated, and really aren't meant to run the current that injectors/computer demand. According to the link, initial seat of the pants dyno reported a mild power gain if anything, but much smoother throttle response.

Personally, when I get my RD350 running (hahahahaha) I'll stick to carbs, strictly out of convention. If you're having trouble with the fuel supply, it will be a lot easier to reference the internet for jetting support than megasquirt maps.

And for your viewing pleasure, here's a picture of one of my favorite RD400's (very heavily modified...)
Oct. 10, 2008 12:41 a.m. Osterkraut Reader

Convert to a Hal effect wheel and have MS control a coil pack. The Ford EDIS system is natively supported, I think.
Oct. 10, 2008 7:14 a.m. therex SuperDork

I came in here to post MitchellC's link. So, my work here is done.