Quote:Bad idea. This is designed to work correctly at the original length.

Quote:Do you mean the idle speed screw? Look at the linkage and make sure that the throttle is closing all the way once the engine is fully warm*:
- If it's not closing, figure out why
- If it is closed, but still won't idle down, you have an air leak (vacuum leak)
- It idles down but dies (and will only keep running at high idle), the anti-dieseling valve (fuel cut-off valve) might broken or not installed correctly.

When cold, the choke is supposed to keep the idle higher.