As the topic states, I have a engine that's started breathing heavily from the breather tube. It's been standing for a while during the summer, only moving some pallets around, no hard work. Now I was running it a couple of hours and saw grey smoke from time to time coming from behind, so I checked and it's breathing quite heavily from the breather tube. Is there any other explanation that compression passing the pistonrings down in the crankcase i.e. rebuild of engine?
I think you have hit the nail on the head, not a lot else it could be. luckily there are complete engine rebuild kits out there for those engines, they come with pistons, liners, all seals, big ends, mains and thrusts, or you can just replace the pistons and liners, but then you need head gasket, inlet exhaust gasket, rocker cover gasket, sump gasket, big ends, etc so your 3/4 to a kit anyway. what you do depends on
Just a couple of quick questions, before you tear into it. Where is your oil level? Have you gotten her up to operating temp? What does it look like under full stall? If your oil level is high, it causes extra drag on the crank and slings oil on the liner walls vs the cooling jets spraying the bottom of the pistons and wrist pins. You said, "no hard work" She might be full of moisture from sitting so long. Oil water slurry takes forever to boil out. Frequent short jobs never reaching operating temperature adds to the problem. If I were you, I would change the oil and filter. Then I would do some good honest work with it. Once she's up to temp, I'd put your gear selector in manual or service mode. Select 4th gear and load the engine against the brakes 10 seconds at a time with 20-30 second cool down in between. The trick is , we're trying to get maximum boost from her. Have someone observe the draft tube from a distance. See if she doesn't clear right up.
I've been snowplowing during the winter our road, but summertime the machine has only been moving around some pallets or other stuff. Short runtime less than 1 hour, maybe a couple of times per week, sometimes less than that. Starts good, good idle and doesn't feel like it runs badly under load or anything. Next is oil and filter service. Will report back after that.