Powervalve adjustment help--Zuki Quadracer

[ccdhowell]

I need help adjusting the powervalve on my '90 LT250R.

I bought this machine not too long ago and am now getting to the powervalve. The engine doesn't behave like a powervalve engine IMO. It acts like it doesn't have a powervalve; essentially it doesn't/isn't working.

First, can I take out the powervalve to check it and clean it up without pulling the jug? How hard it a job like that?

When you look at the adjuster on the left side of the engine, "250" is up and "0" is in the down position. I can turn the adjuster but it is quite difficult, requires pliers. Anyway what is the starting point? Manual says turn it one turn counterclockwise, I can do that, but where do you start from?

Any tricks/tips to getting it right?

And can I adjust it at the track? I've heard of guys adjusting the powervalve for track conditions; good to do or shouldn't do it?

Thanks, Chris

[SWIGIN]

the starting point is where the cap is with no tention on it.

take off the retainer and pull the cap off and you will see the spring and how it works


for what its worth i never like to put 1 turn on mine .....just a tad

[ccdhowell]

If I understand what I've been reading about how this PV works, your putting only a little spring tension in makes it close faster and come on the pipe at lower rpms, resulting in a less smooth transition into the midrange and topend. That sound about right?

[SWIGIN]

the spring is only for fine tuneing...... there is a cyntrifical weighted grear that controls the opening.

[cr480r]

I bought this machine not too long ago and am now getting to the powervalve. The engine doesn't behave like a powervalve engine IMO. It acts like it doesn't have a powervalve;

Honestly the linkage could come un-hooked and you probably would not even notice the difference... The powervalve doesnt do much on a LT...


essentially it doesn't/isn't working..... First, can I take out the powervalve to check it and clean it up without pulling the jug? How hard it a job like that?

You can look through the inspection window to verify operation... just give it a quick rev and watch to see if the linkage moves upward... The valve cannot be removed without pulling the jug... If the valve is not stuck I would not worry about it until you service the top-end.



Any tricks/tips to getting it right? And can I adjust it at the track? I've heard of guys adjusting the powervalve for track conditions; good to do or shouldn't do it?

Thanks, Chris

One turn counter-clockwise on the return spring and forget about it... trying to fine tune it is a complete waste of time... Buy some carb jets instead...

[ccdhowell]

Thanks guys, I adjusted it and rode it today just around the neighborhood to see how it would respond. I guess I did it right, it has much more power on the bottom than before. I didn't open it up too much at all, neighbors don't like me screaming through the neighborhood. Much more responcive now, I think I'll just leave it alone for now. Chris