Plug the exhaust purge hoses

[dannemartin]

An added benefit is the hot exhaust that was "held back" in the engine is released sooner, thereby effectively reducing internal engine temps. The new engine opens exhaust ports even later than the old,,, so it should build up more heat too .... has anyone tried this yet?

 

[thefullmonte]

I already reccommended this to some friends. I wouldn't hesitate to do this mod at all. It worked great on the IQ motors and helps eliminate heat build up around the exhaust port. Remember that because of the guilitine style exhaust valve, there lacks a cooling jacket around the exhaust port. Opening the valves prevents as much heat from soaking the area. Another thing to consider is that they are being held closed for epa resons, not performance reasons.

Added benefit of better accelleration and low end response is what most people noticed on the IQ. If you are on and off the throttle a lot the vacuum pressure activating the valves is instant with the valves capped. Where as other wise you have to wait for the solenoid to close each time and then wait for the valves to build pressure. Depending on your RPM they may never open for extended periods (ex. tight tree riding).

I understand the race teams even cut the valves so they don't close the port as far. I have even heard an idea of using an O-ring on the base of the valve shaft to prevent it from closing as far too. I'm told they close too far and that there is more low end to be gained by doing this.

 

[m8sandman]

being new to the pro and not familiar with the powervalves, anyone got pics and a procedure to do this??? i'm a tree rider so this sounds like a good deal...

 

[NapaMatt]

look in the IQ section... in the sticky...

there is a thread on this