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View Full Version : Briggs & Stratton Engine Crank Weak


dntran08
Aug 28, 2008, 08:29 PM
I have an old MTD tractor. It has an 18 HP Briggs & Stratton engine. When I try to start it, the engine turned, but crank very weak. I charged the battery overnight and fully charged. I got the same symptom. The engine crank week. I felt the cable on the battery, and they got hot. Is it possible that I got a short in the starter, or the starter just week? Anything else I can check?

Birdiemaker
Sep 11, 2008, 09:08 AM
I have an old MTD tractor. It has an 18 HP Briggs & Stratton engine. When I try to start it, the engine turned, but crank very weak. I charged the battery overnight and fully charged. I got the same symptom. The engine crank week. I felt the cable on the battery, and they got hot. Is it possible that I got a short in the starter, or the starter just week? Anything else I can check?
Is it an OHC engine? If so, I had problems where it spun to the Compression point and stalled out. Appearing slow! Once past that it spun hard again till it hit the compression stroke. If this is what you are having here's a solution I used successfully. Remove the cover from the valves. A wrench and Star screwdriver are needed to adjust and lock the valves and a feeler gauge between .003-.005 inch. Clearance should be measured just as the spark magnet moves past TDC, just off the magnet. Be sure it's the compression stroke and not the Exhaust stroke. Adjust valves, both at this point. Info. Tilting the engine such that oil gravitates away from the Valve cover helps but you shouldn't loose much anyway, use a big rag. Replace cover,and plug if you removed it. Should spin much better now. Good luck. Edd [email protected]

crigby
Sep 11, 2008, 03:24 PM
Hi,
Judging by the "old" description you have an opposed twin valve-in-block model. Again by your decription that the wire to the starter got hot I would say that confirms a good battery and a partially shorted starter. Not too fun to replace on that engine. 7/16" wrench to remove the battery wire and 1/2" to remove the two bolts holding the starter to the engine. Be aware that there is a recess in the bottom of the flywheel(actually one on each of two opposed sides) that will allow you to remove the starter without considering the removal of the flywheel.
Peace,
crigby