Originally Posted by
av8tor1977
I have a Stihl 62cc engine that I converted. It was a labor intensive conversion, but it turned out very well and runs great. I was perusing the technical data and specifications for the Sthil 62cc, and the timing was listed as "X" millimeters before Top Dead Center. Just for grins, I got my degree wheel and dial indicator out and checked the numbers. Guess how many degrees it turned out to be.
28 degrees, just as Bill and TKG and Ralph have been telling us for years!
Of course it never hurts to experiment. There is an engine I build that uses an Echo 25cc crankshaft in an Echo 23.6cc engine. It very definitely prefers 24 degrees timing, while the stock Echo 23.6cc engine likes the more normal 28 degrees. An engine needing less advance is generally believed to be burning the fuel more efficiently all else being equal, and my Echo stroker engines do run very well. Who knows exactly why they like less timing..... Probably something to do with the increased piston dwell time at TDC with the longer stroke.
AV8TOR
We have a volvo Penta petrol engine 3 L 4 cylinder. it's states on the rocker cover to set the timing ignition at 2 degrees after top dead centre but the engine doesn't like to run at this setting as soon as we advance it to about 7 degrees before top dead centre the engine smooth out the engine likes to run at that setting. would you say this is the correct setting or should i leave it at or am I missing out on something ?