RE: 55 cc engine
I think what happens is when a engine is mass produced, the proto type is all well and good for balance. But different items get farmed out for production and a gram or two is gained or lost somewhere and they are not as smooth as they could be. Like I said I was very leary and also carefull in that aspect, when I balanced the rotating assy. Who knows maybe I just got lucky. When I first fired the engine I told my wife I may have to get the wings from the trailer just in case. But after seeing how things went I left them off on purpose, so folks could see for themselves. Over the years I have seen in the larger car and truck engines just what a good balance job can do.
It may have a bearing on the top RPM's i'm seeing also. It sure can't hurt *S*
I realize that a single cyl engine can't be in perfect balance, at all phases of the stroke. But they should be equal in weight each way from the centerline of the crankshaft in my thinking.
Honest I was as supprised as you guys were, when I seen the reading on the tach. I was looking for 7-7300 with that prop but certainly was excited with the 7950 reading.
I will do several more tests with different props, get some good pull readings with each prop and also get another tach just to make sure things are correct.
After and only after I get some run time and see if what I built will hold up to the hard use we put a engine through would I consider making any for the public and then it would be on a one on one basis.
BTW I will be making another engine exactly like this one to test also, we'll find out if it was a fluke or not.
It doesn't take as long as a person might think to do the machining of the parts. More time was spent in preparing blueprints, fixtures, tooling and so on.
Richard.