They made a lot of tar and gummed up the engines if you used wet wood, or they used a lot of charcoal which of course it is all labor intensive. They had other issues like they broke down a lot. Easy to repair if you could get or make parts, but it was still downtime. They used charcoal to get them started then added the wet wood. At least that is what I vaguely recall a Canadian telling me, and if in fact that is what he was talking about.
They logging companies switched to diesel because of the downtime, labor costs and parts supplies. Either in the 60s or 70s. I have seen one but it was a diesel one and broken down in the 70s, and they couldn’t get parts for it. And of course the parts weren’t that cheap after all the shipping handling and mark ups along the way when they could get parts.