QuestionHi, John. I've had a little bit of experience working on small engines and I enjoy tinkering with them and learning more about them. I was given an MTD Ranch King riding mower (1996 aprox., 14.5hp Briggs engine with overhead valves) that had a blown head gasket and had set in a shed for a couple of years. It appeared to have been abused (the tie rod was bent, the deck had some damage and one of the blades had been replaced), but it all looked easily repairable. It was leaking oil, so I was a little concerned that it had been allowed to run low on oil, but I was assured that wasn't the case...and the price was right. I completely cleaned the carburetor and fuel system, replaced the oil pan gasket, had the slightly-warped cylinder head milled (the block was true), replaced the head gasket, reset the valves and adjusted them, and did the routine maintenance. Now it starts easily and runs, but it won't build up to full speed. It runs better with the air filter off, but a plume of fuel and air mixture comes back out of the carburetor. When I rotated the flywheel to set the valve clearance, the intake valve closed, the rocker arm cleared (which is when I set the clearance), then opened the valve slightly as it opened the exhaust valve, then cleared again. It appears as though the intake and exhaust valves are open at the same time for a split second. Is this normal?
On the fuel delivery end of things, the float in the carburetor appears to be working properly, and the carburetor does not appear to be adjustable. There is a needle valve that is controlled by an electronic component that is mounted to the underside of the fuel bowl. The engine dies if I remove the connection, but beyond that I cannot determine it's working order. I removed the carburetor and checked it again, and it appears to be clean. I checked the throttle cable to make sure the carburetor is completely open, and it is. The choke is open, too. The engine will build up to speed momentarily as it runs out of gas, which leads me to believe that it is running too rich, but I can't figure out why or how to fix it. I'm tired of push mowing an acre and it's just plain driving me crazy. Help!
Shawn
Answer Hello Shawn:
Are the Valves Set at .013in Intake and .017in Exhaust. On some Engines the Book Settings are Too Close and Cause this Problem. It Sounds like the Valve Lash May be too Close. To Check the Carburator Soleniod, Remove it from the Bowl and Put a Bolt in Place of it. Put the Bolt in Just Far Enough to Seal the Opening. This Soleniod May be the Problem as it Regulates the Fuel Flow. Start the Engine and see if it Revs then. If so the Soleniod is Not Functioning Proper. Hope this Helps. Let me know what Happens, Please.
Good Luck
Respectfully
John
