701 yamaha dasa pv help

[damonsky]

looking for help tuning power valves on a yamaha 701 sj with a dasa flat top 85mm bore and a 5mil crank and b pipe. is there different springs to get or can i cut them? all the parts i have now are what i got from dasa. it pulls hard and runs strong. just looking for some info on how to tune them to get it right .thanks

 

[kevbo]

Ive got a better question. How do you get a diaphragm operated powervalve to go from full closed to full open in the .1/second that it takes a freestyle engine to go from 4000-7000rpm?

 

[wsuwrhr]

Serious?

Ive got a better question. How do you get a diaphragm operated powervalve to go from full closed to full open in the .1/second that it takes a freestyle engine to go from 4000-7000rpm?

What do you think is happening in that .1 second that the engine is accelerating?

 

[wsuwrhr]

looking for help tuning power valves on a yamaha 701 sj with a dasa flat top 85mm bore and a 5mil crank and b pipe. is there different springs to get or can i cut them? all the parts i have now are what i got from dasa. it pulls hard and runs strong. just looking for some info on how to tune them to get it right .thanks

You don't need to cut the springs, the blue(or red) screws in the caps turn in or out by clicks, it is a normal right hand thread, stick a small craftsman screwdriver in any of the slots, turning the screws increases or decreases pressure on the spring.

Turn them in(more pressure on the spring) for later opening or out(less pressure on the spring) for earlier opening of the power valve.

Just make sure whatever you do to one screw, you do to the other. They need to be even.

Please let me know if this helps.

Brian

 

[kevbo]

I think that they operate too slow for a freestyle engine.

 

[wsuwrhr]

I think that they operate too slow for a freestyle engine.

Then I would like to hear about your experience and your setup. First off, please tell me you use a Lamey PV cylinder.

Use the cylinder with no PV, the bottom end feel will feel quite different.

As the stroke and bore get bigger and bigger, the PV does become needed less and less because more of the exhaust area is used.

Brian

 

[joesuperjet]

I think that they operate too slow for a freestyle engine.

Lol, That's a new one to me. They work fine in all our 8 mm Lameys and 66E race engines. And I would be willing to bet your "freestyle" engine couldn't hold a candle stick to any of them...


JAM

 

[kevbo]

How would you know the difference until you used a solonoid operated PV?

 

[wsuwrhr]

How would you know the difference until you used a solonoid operated PV?

Could you start your own thread and we can talk all you want about it.

Your posts are completely off topic