Yanmar FX 335-hard to start and sounds like it's missing at low rpm.

[Car Doc]

I would be happy to help you (and anyone else either) if the tractor was here. Guarantee we could salvage it and you could go on with life and I am not joking it wouldn't be 5 grand all over again. I can only imagine what the inside of it looks like after the "overhaul". I only hope the next guy you find is not a shyster like the last ones were it should last you a lifetime seriously you can expect that. It could be missing simply because it could have a tight valve but who knows.

[kenmac]

Not bashing you So,I hope you don't take my comment that way .I really hope you can get everything straighten out for a fair price.That said, We have heard stories like this many times from people that bought a VN rebuild tractor.Again not bashing anyone with a VN recon.as,some menbers have had good luck with them,but IMO, it's a crap shot. You should take it back to the repair shop that attemped to repair the tractor and ask for your $$ back or repair the tractor properly.There's no telling from behnd a computer what he has done to your tractor incorrectly. I wish you the best

[tractorErnie]

Ive had an FX335-D for 4 yrs now,its my second one, I put new rings in because it smoked a lot but it purred like a kitten. After the ring job it still smokes a little, but not like before the new rings. If I were you, I would pull the injectors out and have a diesel shop check them out and either clean or replace them.
Also I would run synthetic oil in the engine that seemed to help our tractor smoke a little less.
Also they are a 4 cylinder.

Ernie

[California]

TDP, it sounds like your mechanic doesn't have experience with anything similar.

Yanmar was building the engines, and in some cases the entire tractor, for John deere during the era when your tractor was built.

I think an experienced Deere mechanic would understand it easily, and could get it straightened out. I would start there.

[Neat 1500]

Any 1/2 decent diesel mechanic should be able to fix it no matter what it is. brand is not relevant at all, they all are built and run on the same principles. i get a bee in my bonnet when they give excuses like" dunno whats wrong with it, take it to a (brand X) dealer". i am an electrician by trade and we dont go saying " oh i cant find the fault in your house, i dont use that brand of cable or outlet........."

[firemanmike69]

If you have a temp gun ($30 at harbor freight) check the temperature of each cylinder's exhaust ports. A low temp would narrow the problem to that cylinder and troubleshoot from there. If you don't have a temp gun, a less scientific method is to spritz on water and it'll evaporate on the good cylinder exhaust ports.

Also, check fluids for signs of the oil/coolant mixing. Is there oil under your radiator cap? Is the level on the oil dipstick increasing?

You can also crack injector lines one at a time while it's running and listen for the engine sound to change, it should lug the engine down each time if it doesn't thats the dead cylinder

[TDP]

Ernie, It is a 4 cylinder. They supposedly replaced all 4 injectors. Talked to them today and they want me to bring it back for the 3rd time. It took them 3 months to rebuild it, 3 weeks this last trip, and who knows what down time the next trip will be. If I knew what to do I would do it myself. I think I will try synthetic oil. What brand do you recommend? TY!

[284 International]

I wouldn't spend any more money putting synthetic oil into the engine. You have problems worse than that, there's no reason dumping good money after bad.

[Car Doc]

I would stay away from synthetics also these engines are so loose tolerance you couldn't keep it in, that would make it worse not better.

[winston1]

One good thing is they haven't give up. Maybe they will get it this time. I agree, oil is not the problem.