Well, I snuck out to the garage this morning and dismantled the fuel pump on the 280S. Found the diaphragm to be OK but there is a screw-in mesh filter that was completely clogged. Cleaned, re-assembled, tested and found that it pumps.

Tonight I re-routed the patented gravity feed to go to the pump. Cranked engine and it sputtered. Stuck shop rags in primaries to simulate closed choke (chokes don't work) and it started and ran. Removed rags, and as it warmed up, it smoothed out and readily held 1500 to 2000 RPM. Not quite idling, but I can fix that now that it is running.

One remaining problem is a leaking fuel return valve.

Conclusion 1 - earlier problems (Zenith 1, Chuck 0) were caused by fuel starvation in rear carb caused by inadequate fuel pressure.

Conclusion 2 - if you have an M130 with the old-style fuel pump, check out that screw-in filter for debris. The later style has a filter over the diaphragm housing which you replace from time-to-time.

Chuck

Chuck..

When you removed that fuel strainer/filter, did it make a mess?? What I mean is, what will happen if I try to remove mine?? Will gas pour out of the open hole? Should I try to plug it shut??
Should I leave it alone???? (hee hee)

~Christy