Husqvarna + Wiseco Pistons

[cello]

Has anyone else tried running a Wiseco piston in their 2 stroke husky - Preferably a Enduro ( WR/WXE 250 1996 ) , with any success .

I have recently tried and now have lost mid-high range power - Not sure what the problem is but it only resulted after replacing the Piston. Anybody elses Wiseco experiences would be of interest.

Cello

 

[the Eel]

I have been using Wiseco racing pistons that are made for and sold by Fast By Ferracci. I have had no problems whatsover. I have read that a very careful break-in procedure is required for Wiseco pistons. I was careful with mine and they have held up great - remarkably long life on my 125 and great performance.

 

[SPD]

Thats whats in my wr250. Was put in last Sept. Doing great so far.

 

[DEANSFASTWAY]

Yes Ive used quite a few of them in the past , They are nuch cheaper esp/ for the 360 . The newer style 250 motor uses a 98 CR 250 piston , We found that out when the new bikes came out and we couldnt finda piston for them . @ 2years ago . I think the one FBF sells is like the CR WISECO but with an intake hole .Theyre forged so you break them in a bit and always warm up engine ..

 

[Glitch]

Is there a powervavle on your bike that could of been messed up when you replaced the piston and removed the cylinder. It's just a guess.

 

[cujet]

I cannot find the related older thread to this one. However I posted on that one the probable situation. The powervalve is not opening. I suspect the internal parts are not assembled correctly and even if you see the lever move, the internals are stuck closed. Pull off the PV cover and let us know!

Chris

 

[cujet]

In addition, the Wiseco piston is exceptionally close to the stock unit dimentionally. Therefore, unless the wrong piston is installed the port timing will be exactly the same as it was before. I feel it is very, very, very unlikely that proper Wiseco piston will cause any power loss at all.

That said, I would guess that the rollers were left out of the PV assy and they are not being pulled open.

Chris

 

[cello]

Guys

appreciate all your responses , found the problem . It was the power valve . It appeared to be binding to the barrel in the closed position. The only question now is what should the clearance be between the valve and the piston ( in closed position ) . I meauseured it and its currently about 5 thou inch.

Thanks again , the idea of wiring the valve in the open position was pure class ;-)

On another topic is there a place in the USA you can hire a Enduro bike and ride offroad. Not sure if the East or West coast is more hospitable to offroaders.

 

[TM-Frank]

Clearance between piston and PV should be 0.4 - 0.6 mm.
This information is taken from the 89 WRK workshop manual, but the engine is basically still the same.

 

[cujet]

I like to run lots of clearance to the PV. The difference in power is slight and the safety factor is important. Also, the PV's tend to move around as they wear out. this allows a little sideways motion and can put one edge of the PV in touch with the piston. I have the manual for that engine, however it is at work, sorry. By the way, you can easily hear contact with the piston at idle.

Chris