Have you adjusted your valves lately? I often read the first sign of valves being out of adjustment is hard starting when cold.
It did that because you used starting fluid. I can almost guarantee your valves are still tight and need adjustment. It's a known issue for the 660 engine. If the valves are adjusted correctly, you will not need starting fluid.Ok replaced plug and sprayed just quick squirt of starting fluid and this thing fired up better than it ever has.. Go figure.
The longer you leave it the more chance there is of carbon fouling the seats & giving bad compression down the track or (worst case) burning a valve out if they tighten up too far.Yes Im going to check it as soon as deer season is over. Im sure they have not been checked in a while..
Glad to hear you got your problem fixedOk finished adjusting valves, this thing fired right up. Even would idle with the choke on. I can hear a little bit of a lifter noise but these things where way out. I guess a little noise is ok.