lol her engine on Woodmizer 35 keeps dropping cylinder

[69bsa650]

We have a Woodmizer 35 2012 that keeps dropping a cylinder sometimes not even underload. It will backfire at some point and then both cylinders will run fine for a little bit until it drops the cylinder again. Should I be looking at the coils? I did change the plugs And they needed it. That mill runs six days a week.

[WV Sawmiller]

  Sounds like a bad coil or loose coil wire? That sounds like it would do something like you are describing. I have had to replace a couple of coils on my Kohler 25 on my LT35 and I'd lose a cylinder - usually after it had warmed up.

   I keep a couple of cheap testers I bought from HF to check that. Just stick them on the plug as I remember and watch the light flashing when running or stop when it is failing.

[jpassardi]

I agree, sounds like coil/wire assembly. Check for consistent spark. Be sure to get the correct ones for your SN engine. My 25 HP Kohler uses shielded wire assemblies.

[Ben Cut-wright]

What tests have you done to confirm the engine is "dropping a cylinder"?  A cylinder not firing for any length of time can be detected by examining the spark plug. Heat related coil failure is common, might spark OK until the coil heats up.  Check for *maximum spark at each plug when the miss is occurring. An intermittent failing coil will usually NOT pass a coil stress test.

What did the plugs look like to make you say "they needed changing"? 

[beenthere]

69bsa650
Welcome to the Forestry Forum.

Many members will try to help.

Previous two threads you started, some help was offered but needed some questions answered to zero in on your problem. But no response back from you. Did those problems in April 2024 get solved ??

[taylorsmissbeehaven]

I had that happen on my LT 35. replaced the coil and problem solved. I was on a job at a local botanical garden when it happened and had to finish up as I had a window I could have my saw there. I continued to run it and eventually gas "washed the cylinder" and got into the oil. took me a while to figure it out but in the end it was a bad coil. Running your saw that much might have similar results. Hope this helps