anybody use a compression valve ona 2 stroke

[jimg1au]

hi
just wondering if people use them and how they work.i use a valve lifter on my tt500 and kick through but on a 2 stroke do you have the valve open all the time
thanks
jim

[Freakshow]

i have used one on the track bikes, have a few here that you just screw into the spare plug hole, guess you can use them to start bikes , but mostly used it on speedway style tracks with big lon corners, that you want to wash of speed BUT NOT BRAKE, or you can hold it pinned but pull the decomp on so it only cuts the power out till you release it again.  it works by just blowing the compression off and gives you some engine braking effect.

the valve will need to be closed at all times WHEN NOT IN USE or you have little or NO compression. same effects as if you just removed the spark plug.

[090]

Yeah Jim, all the big Maico's use them. Just hold it in till its started. It will run with it in .

[jimg1au]

thanks brad
cheers
jim

[montynut]

I think the Maico decompressor is half way down the stroke to assist starting? The Montesa Enduro bikes and Trials bikes of the mid '70's had them in a second plug hole to assist engine braking on steep downhills  and to help dry out a drowned engine .