Here is what we did and the results of the tests....
Complete fuel system cleaning with new filters and lines.
Fresh gas/oil mix added.
Carb disassembled, cleaned and check (was not very dirty at all). Fuel pump also.
Compression tested at 95 PTO and 105 MAG. (low but think it will go up after running as rings may loosen up)
Good spark on both sides.
Removed airbox and check for mouse nest (was clean as can be)
Removed exhaust and check for mice nest also(none found). Blew air through( OK)
Started engine. Runs but does not sound right. Idles at 1500 rpm( too low) That is the first problem. All lights and gauges work.
The second problem is we could not shut it off.
Had to unplug external coil to kill it.And the giant killer.... absolutley nothing happens when you squeeze the throttle.
Rpm stays steady, engine sound does not change. (throttle cable is fine, carb slide moves freely).
Ok so after it stopped we found that the PTO side of the exhaust manifold is cool to the touch. The Mag side is hot. Spark still good on both sides. Plugs look ok.
Restarted engine. Unpluged wire from pto spark plug and rpm didn't change.
Unplug mag spark plug wire and rpm drops and after 10 seconds engine dies.
Checked over wiring to find out why key or kill switch will not stop the engine. Wiring is in very good shape. No splices or modification of any kind. Tested switches with meter... good. Checked continuity of wires with meter. Found yellow wire from stator had bad crimp connector at the terminal block on bulkhead. Fixed it and tested good.
Continued testing ignition wiring and found an open between the the terminal on the block where the white/black wire from the two switches and the engine itself. Attached a aligator jumper wire from terminal to engine. Tested spark. Ok now both switches work and will shut off engine. So we assume that the engine ground connection on the stator is bad. Disasemble recoil, remove flywheel, find screw with brown wire. Removed screw. Clean up some corrosion. Reattach wire with screw and retest. Still open. OK so we have a bad brown wire.
Left temporary jumper wire between terminal and engine case so we could use key to work on engine problem.
Removed carb from boot again. Recheck everything. Started motor. Nothing changed except key now works. Removed entire exhaust. Run engine on open manifold. Still will not throttle up only now it is louder.
Recheck spark and retested compression. Now 100 and 110. Removed both heads anyway. Gaskets looked fine. Slight carbon build-up on both pistons. Domes look fine. Cylinder walls look excellent. Some signs of detonation on heads but I've seem worse.
Reassmeble engine and restarted (always starts on one pull by the way) Nothing changed. Sprayed starting fluid on PTO crank seal. No change in RPM. Still limping on PTO side and no throttle responce what so ever.
OK guys.... I give up. I am out of ideas. We spent 4 hours on this and are no closer to the problem than when we started.
Any thoughts, ideas, observations or comments would be appreciated.
Thanks, Todd
