4020 diesel not running right?

tomstractorsandtoys

Well-known Member
I bought back the 1968 4020 that my Dad bought new. It has less than 6000 hours and has less than 1500 on an overhaul due to a broken piston. The tractor has a M&W turbo that was installed in the late 1970's. The turbo was installed for better fuel efficiency and not just for more hp. We bought it three years ago and replaced several hoses and gaskets and readjusted the valves. The tractor just does not have the right sound to it and seems to lack power. We pulled the pump and injecters and had them rebuilt and still not much better. At about 1800 rpm there seems to be a slight miss. I have played with the timing and that helps some but my other high hour non turbo 1968 4020 just has lots more power.I did find out that the shop that did my pump has no heater on his test stand bench so he has cold fuel which I do not like as head and rotor problems show up much more when hot. The turbo seems tight with no play. What else should I check? Should the pump go to another shop? He put a complete kit in it and I told him to set the fuel up some but not to go over 10% because with the turbo that should be about 110 hp. I just hate running something not right and am not sure what to do next. Thanks Tom
 
I have O/H'ed several this winter, and found most had the valves set in too deep into the head, a lot of compression is lost there,, and most of then had bad valve guides,, so new seats,valves,guides and a light planing on the surface has a lot to do with the performance,,and I have been using Reliance high compression pistons..this cleans them up and makes them run great,,and yes I just spoke of a big job...but it's worth it,,been costing about $1200 for the head work and rod resizing..got a 3020 in here right now to put together this week this way.. A bad guide will give you a sloppy valve seat,,and reduced compression will add to bad performance..and give you the results that yours is giving you..
 
I have a head here that was redone last winter for an engine we bought to rebuild that did not get done yet so maybe after first cutting of hay is done I will pull it in and do a switch. My friend who does my heads is very particular about the valves as that it what it takes to make a Deere start. Thanks for the idea. Tom
 
Drop a new set of pistons/liners in while you have the head off...then you will be happy with it..
 

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