I bought a 1975 John Deere 310. It's a pretty nice old backhoe everything is pretty tight. The only problem is the 3 cylinder motor has a erratic miss with the breather off the valve cover it sounds like a air compressor in there. Pulled the injectors and had them tested and where all good. Any ideas?
I would check engine valve settings, and do a cylinder pressure test, may have a valve issue. How many hrs. on the unit.
Just took the head in to the machine shop to have it checked out .Ran the overhead and it didn't change a thing. The machine has pretty low hours for a 1970s 310 around 2800hrs
Did it look like you had alot of blowby out the breather to start?push rods straight,rocker arms free on shaft, any adjustment screws adjusted down more than others?. I try to get the cylinder pressure test before the head comes off on this type issue. Hope the machine shop finds it in a valve! how's the pistons/liners look.
No blowby out the breather and I should have checked the cylinder pressure first got in a rush to find something big in the head. I'll check the pistons over better tomorrow they didn't look bad at all. The hole motor is very clean inside they must have used good oil and changed it often.