It cranks great with plugs out. Battery is good. Seems like ACR automatic compression release is not working. Luckily it starts easily once I hold the key and get past initial compression. Any experience with this or knowledge of the ACR mechanism? I adjusted valves and did not see a "bump" on exhaust valve. Also checked electrical connections.
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Toro MX4250 zero turn with Loncin 708 v-twin engine cranking slow
- Thread starter dtestin
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Export threadI have yet to see an ACR failure on a Loncin engine, but this could be the first. What did you set the valve clearance at? Can you give us your engine model numbers and I’ll see if I can find a service manual for you. This manual is probably not for you engine, but will show you where the numbers are located. https://www.toro.com/getpub/70680
Here is a service manual for that engine. I would start by double clicking the value clearance first, as you may have set it on the intake stroke,not the compression stroke. https://www.toro.com/getpub/117255
Valve clearances are set according to specs on compression stroke. Mower runs great but just have trouble getting it to crank. It can just barely overcome the compression if I hold the key for several seconds. Other ideas?
Check you battery voltage while trying to start the engine. You may have a battery which is getting weak, voltage is dropping below 10 VDC, or a bad ground connection.