250-500cc Power valve control

[raisrx251]

If you look at the parts fiche on the left case where the spring is located, I ordered one of those washers in there and then used the size and diameter to machine a thicker washer. That set a little more pre-load on the spring. Like I said I am not sure if this ever helped or not as I also raised the compression at the same time.

 

[Eurofreak]

Do you want to preload the spring? Doesn't the spring resist the ramp and ball, hence delay the opening of the valve? Or is the valve opening too early? I like the bottom end, wouldn't mind getting the hit earlier.

 

[MOTORHEAD]

I've wondered the same thing too. Opening the valve earlier might be better. Maybe the bottom end last too long?

But, someone from across the pond said they had used a 1.3mm spacer with good results.

Something that needs to be tested.

 

[MOTORHEAD]

OK, I did something a little different the other day and it seems to have helped. I loosened the bottom stop and took a screw driver and pushed the gear plate up until all the slack was out of the linkage. It was pretty easy to tell when it was tight, then I just locked it down.

I didn't pull the head and measure how much that moved the main flap, but I'm sure it did go up some. But, between the two it did give a positive result, the transition in the power isn't nearly as noticeable as before.

 

[HuskyDude]

I loosened the bottom stop and took a screw driver and pushed the gear plate up until all the slack was out of the linkage. It was pretty easy to tell when it was tight, then I just locked it down.

I didn't pull the head and measure how much that moved the main flap, but I'm sure it did go up some. But, between the two it did give a positive result, the transition in the power isn't nearly as noticeable as before.

Do you mean here.

Husky recommends (.4 -.5 mm) clearance between the P/V's and piston. The slack can be taken up here on the linkage.

 

[MOTORHEAD]

That's the 125 style linkage isn't it?

I took mine up on the other side, behind the pipe where the bottom stop rests on the cylinder casting.

 

[Norman Foley]

Ben Smith rode a WR250 at the ISDE in Portugal. It was equipped with a Provini PV adjuster and he was impressed. He tried to trade his WER steering damper for it, but didn't work out. I think someone should try to import a small number of these.

 

[MOTORHEAD]

I agree; There's something for someone like WER to look into.

 

[Joe Chod]

was thinking something else. Both 125 and 250 use the same ball/cup/ramp govenor. they differ buy the actuating mechanism as the picture points out. I was thinkng....rather than change the spring rate with a shim or even a provini type thangy...he weight of the balls in the govenor/actuator. a heavier ball would move quicker as the centificl force goes on and open the valve quicker. Same size ball but of tungsten for example would give that effect. Just got to get some same size and then get some weights using a dopers drug scale (must be borrowed of course!) to se from the stocker. Rekluse uses a combination of them with steel to give different desired engagement effects. Just saying.

Joe

 

[Eurofreak]

True Joe. Would you measure the balls...

 

[Joe Chod]

True Joe. Would you measure the balls...

After watching you ride the other day......I would say your measurement is 0.0........Mr. Blutarski....has no grade point average......all courses incomplete.

 

[wallybean]

The Rekluse balls are quite a bit bigger than the balls in the PV. First thing I did when I had it apart was compare. If you can find some tungsten balls that diameter let us all know. I didn't look as getting a spring was much easier. The combination of heavier balls and differing springs would give you a lot of variability.

Let us know what you find,
Walt

 

[Eurofreak]

0.0? I have to swing 'em out of the way just to get on my bike! you must have me mistaken for some other ball-less rider

 

[robertaccio]

No word yet from Tullio P about US market purchase/shipment, will keep you guys informed.R

 

[wallybean]

Joe,

The PV balls are 11/32"(.343"). I went ahead and ordered 4 of these to experiment with if I can ever get ambulatory. Cost of the 4 Tungsten Carbide balls is $22 without shipping.

Walt

Springs were about $15 appiece

 

[robertaccio]

From Tullio Provini

We allready sold in USA our T.E.C. sistem but at the moment we didnt have an importer in California so the cost of each shipment is around 60 € . The price is 325 € without tax and is not included Husqvarna valv cover wich is around 30 € tax included.

Thanks for your interest

Tullio Provini

so if you guys want one for the Husky its the TEC valve plus the special adapted Husky cover and shipping @425 bucks all together. So its available but its a costly piece of hardware.

PS I never heard back from my friend in Italia so I just contacted Tullio myself.

 

[MOTORHEAD]

Thanks for checking into it. I'm going to get one, but I'm just not sure when. I'm just getting over paying property taxes, home & auto insurance and plates, plus I still need to get the 510 fixed. But, sometime in the next month or so I'm going to have to get one.

 

[tm_enduro]

http://www.officineprovini.it/eComShop/eComShop_viewItem.asp?idProduct=5106

i believe TMs come with Provini valves, FYI born on 2 stroke with PV road racers

TMs do not come with Provini PVs.

$425 for a unit that give you bolt on adjustable power. Hmm, sounds like a pretty good deal to me. If I can get GasGas300 power with a few adjustement, yet have a Husky with its parts availability, resale, quality, we have a winner. And with the 2010 models coming with KYB forks that are easy to tune, life is looking so good for the 250/300 Husky.