Victoryrider
New User
I recently purchased a 56 massey ferguson (harris) 50 gas tractor with the z134 continental engine. I want to give it a tune up but I'm having trouble finding info on the correct spark plugs for it. I pulled champion d21 plugs out of it and crossed referenced them to a 386 autolite plug but the tractor sounds like it hates them. Misses and sputters at low rpm and sounds like it knocks now. Never been a fan of champion plugs but this being my first tractor I'd like a little input on what this engine requires. I cannot seem to find it online. Any help would be appreciated