Messages

256

General Two Stroke Talk / Cycle World Two Stroke article

« on: September 15, 2012, 05:08:36 AM »

The bike I have fuel injected is Kawasaki 350 Bighorn 1973. This only a test hack. A VMX bike.

257

Vintage Two Strokes / 1974 Yamaha SC500

« on: September 15, 2012, 12:39:43 AM »

citabjockey, have you any close up pictures of the balance shaft on the SC500?

258

General Two Stroke Talk / Ideas bank

« on: September 12, 2012, 10:08:36 AM »

The misfire you can hear is from copying analog tape to digital. First run ever for this engine.

259

General Two Stroke Talk / Ideas bank

« on: September 12, 2012, 10:06:07 AM »

260

General Two Stroke Talk / Ideas bank

« on: September 12, 2012, 09:51:55 AM »

261

General Two Stroke Talk / Ideas bank

« on: September 12, 2012, 09:47:11 AM »

I like rotary valve engines.

262

General Two Stroke Talk / Ideas bank

« on: September 12, 2012, 07:55:15 AM »

This is the engine you want, 700 tandem twin.

263

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 09:45:00 PM »

Well well, who do we have here? Yes Wobbly and I talk and there has certainly been some input from him. We build some stuff for him and his RZ based engines.
Fuel in the MFI system was pressurized by a small pump run off the flywheel side of the crankshaft. Based on a Honda 50 oil pump. Continuous flow to a tapered needle in the throttle body with a vairable flow back to the tank. When it worked well, it worked very well but when it didn't ( most of last season ) it was a disaster. That's why I started playing with EFI. From what I know now I think I could go back to MFI with a little better results, still not as accurite as EFI.
We didn't see many Euro bikes in NZ, not sure why? Cost maybe? USA sucking up all the stock?
The ones we did see usually ended up broken and were expensive to fix.

264

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 09:17:53 AM »

This is typical of a VMX racing  in New Zealand, mostly natural terrain. Right up to 1985 bikes.

265

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 09:10:58 AM »

This video is pre the vairable rotary housing. The bighorn is coming to pieces  this weekend, as I was taking the photos for you with the throttle body off I noticed the rotary valve is lose. There is a pin that drives the valve and it's had some damage in the past, it seems I didn't do a very good job of fixing it, I'll need to pull the crank out and remachine the drive pin hole out to a larger size. Make a stepped pin to suit. Next time I'm out with the old girl I'll get some video. Our racing starts in a month so it has to be running good for that. I'm going to run in the pre 75 open class with this EFI engine first, untill someone complains. I might have to go back to the old mechanical injection engine you see in the video.

266

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 08:55:11 AM »

This is montage of racing at Wakatane two years ago. Somewhere in the middle is the bighorn running. This was with the lower comp head and the mechanical fuel injection ( similar to a Hilborn system) , never the less it did win one race and second in an other. You can see that the old guy riding it needs to try a little harder!

267

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 07:04:37 AM »

This also had  400 gear clusters, clutch and the DT400 head. Because it had a central plug.

268

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 07:00:50 AM »

This is a DT360 I used to race in VMX a while ago.

269

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 06:59:33 AM »

Very nice. I had one ( 2, one in a box for parts) years ago but in a fit of shortsightedness scraped it! ( them ). I always thought mine was an RT2, it had reeds. I think the RT1 was piston port? The gearbox on mine was not too good. I ended up changing the gear clusters out of a DT 400. The 400's had undercut drive dogs where as the RT's and DT360's did not. Fromm memory I had to change the clutch as well?

270

Vintage Two Strokes / Vintage Yamaha 360, Woods Riding!

« on: September 11, 2012, 04:29:03 AM »

I have to stand on the foot pegs to start it, buggered hip. citabjockey, have you had any trouble with that RT2 gearbox? Have you a picture of the RT parked?