Hey everyone, it's been about 2 years since I have been on here. I have a 1968 124 with the original k301 12hp engine. The machine has been running great until a few months ago when it started running great for about 30 minutes, then all of sudden it starts to sputter, lose power, and then shut off. Putting on the choke MIGHT help me limp it back to the garage, but it doesn't help much at all. I hadn't changed anything right before the problem started, and have seafoamed it, steamed it, changed the oil, replaced the carb gasket, changed the plug, and swapped the battery. I'm still having the same problem.
I got a compression tester in the mail today and tried it out. I started it today with a fully-charged new battery. It tested at 75 psi cold, and held that pressure for 5 minutes. I started it up, and it ran happily until the 30-minute mark, when it started to sputter again, shut off, and refuse to start again. I put the compression tester back on and it still tested right around 75 psi, and is still holding it 10 minutes later. I took the tests with the throttle wide open both times.
Any thoughts?
Thanks