Originally Posted by
av8tor1977
I repair/rebuild/modify, etc. lots of engines. Most of the time they will fire right off with virtually no problem, but every once in a while one will be "balky" and not want to run. Instead of having the patience to pull the plug out and check for flooding, etc., I too will usually just grab the electric starter and away they go. Then as you said, after that they easily hand start.
It is actually somewhat amazing when you think about it, as when hand starting they only get to go past the compression/ignition stroke one time. When using a pull starter for example like on a weekeater, chainsaw, etc., they are turned over rapidly multiple times. But ours still start with that one flip. Of course, most of the other equipment has magnetos that need to turn a bit fast to make a spark, but still, I have magneto equipped airplane engines that fire right off with a hand flip. I think the other factor is that we fine tune our engines to be exactly right, (hopefully), and a chain saw or weedeater may or may not be anywhere close in tune, have a good clean plug, good compression, etc.
AV8TOR
We tune3d the chain saws and brush cutters about the same as a plane engine. High end first then the low end. Max RPM then lowered it a few hundred so they didn't run lean.
Only engine I have had that didn't hand start well is a G-62 with a mag. I tried every position of the prop and all I got was a sore arm and shoulder. I put on a C&H spring starter on it and then it fired the first time every time. No problems with any other engine but this one was in a crash and I did a carb repair, it could use a new carb but once fired it runs perfectly. I'm almost ready to start up a couple engines that haven't been fired in a couple years. If they draw gas right away there should be no problem, if not I will roll them over with a starter. Both have the newer alcohol proof diaphragms so they should be OK. They were both put away after a crash and the carbs were still wet. We'll see what happens real soon.