No worries Dave, it's natural to think that if something's adjustable, then you can adjust it to your heart's content. I didn't know better either, until I started flying with people like David Owen.

Although the learning curve might seem a bit steep, if you can leave the comp alone at a good running setting, it actually makes things easier, because you're removing one of the variables. The trick then is working out what will convince the thing to start. It varies from engine to engine, but mostly I can richen the needle a turn or so, choke it once or twice, maybe prime the side of the piston, and it'll fire up. It'll probably be misfiring initially, but as you slowly lean it out, the engine will heat up and the misfire will clear. Easy! Of course sometimes you have no choice but to mess about with the comp - the engine may be flooded, the presence of a muffler might stop you priming through the exhaust port, or the engine may be just plain perverse. I also think that the better an engine is, the less the comp needs to be fiddled with to get a good run. Things like my R320 and T2.5 barely have the compression touched from one year to another.

Steve