Running Out of Power

[cello]

Just rebuilt my bike Husky wr250 1996 , with a new Wiseco Piston and after running in have found that theres no mid - top end power !

The engine ran perfectly with the old piston in but it was time for a bit of TLC. THe original piston was replaced with a Wiseco - 2638CD Piston which looked identical but was noticed to be lighter then the original. THe symtom of the fault is as if the engine is not breathing properly and the only different part was the Wiseco Piston , Rings , Gudgeon Pin and Little end.

I,ve tried a new plug , cheked the power valve and all appears fine , it must be one of two things...... either the ignition unit is faulty and not firing properly at high revs or its the Piston not flowing the Gas properly at high revs. The bike runs fine @ low revs but does not build power @ mid / high revs , it just seems to rev and not build power.

Eric Can you suggest anything else to check befor ai strip the bike and rebuil;d it with the original piston to verify its the Piston .

Thanks

Cello

 

[WFO]

Sure sounds like the power valve not opening.....which you said you checked. Did you take the actuating cover off and actually watch if it moved when you revved the bike, or just check that it wasn't stuck? And as a long shot, you didn't leave anything in the pipe or airbox when you reassembled it did you?

 

[kdxtaz]

Just a shot in the dark -
You stated, "it just seems to rev and not build power." Could the clutch be slipping?