New Member 416-8 Onan

Any update on this post.....?
I for one would like to know how this ends.

I talked to the mechanic on Friday, then went and picked it up.

He didn't want to (or wasn't allowed to by the manager) do the engine swap, mostly due to the bearing issue. He couldn't find how anyone did it. He thought he could take it to the machine shop and have something fabricated, but wasn't sure how it would hold up, and they would have to warranty it for a year.

He did adjust the carbs slightly and charged me $10.

He suggested changing the plugs twice a year, as they are getting fouled by the burning oil. He also suggested using Premium fuel from now on, he said it burns cooler and that's better for an air cooled engine, especially in the south.

It started right up when I got there, no dragging, hard to start symptom. I was going to go out and start it again when it's cold, but it's rained all weekend and was fairly warm. Later this week it will cool off, I'll see how it starts then. If it starts more easily again, then I'll just run it and keep the oil and plugs changed.

I also need to get a new air filter and foam breather.

Thanks for the information and replies.

There is a common misconception about the fuel thing. Premium fuel burns slower than Regular, not hotter or cooler. That's why it can give more power in an engine that has been designed for premium, as it ignites it will expand and apply even force as the piston moves down. Regular may be burned up before the piston is all the way in it's downstroke and a "ping" or "knock" is the result. What does determine the temperature in the cylinder is the air fuel ratio. Most engines work the most efficiently and last the longest at a 14.7 to 1 AF ratio. That number is based on maximum power along with maximum longevity.

The first thing to do is run that engine the way it was designed to run. Regular fuel (non-ethanol preferred), correct carb settings, straight 30W oil, correct spark plug, and points at .018.

I have a Sun 500 that I've used to set carbs by AF ratio, it's the only way to get one perfect.