Yanmar YM2000 Fuel Pressure/ hard starting

[sd455dan]

The top is mostly carbon and oil build up, not so much wear. There is wear however down towards the bottom and middle of the bore, mainly where you can see that it looks like the piston got stuck.

As far as starting fluid being a possible cause, could be, I never used any, but the PO might have, who knows. I am going to guess that he isn’t the one who did the fancy head gasket work though.



I’ve looked up mostly everything I need, if I don’t do new injectors or sleeves, I’m at about $600. That’s including a new air filter, coolant hoses, etc.

That's good news - Yanmar builds great engines- but sometimes stuff happens.

Be a great work horse for you once she is back together. There is also a sense of satisfaction that comes with fixing a damaged engine. Good work and will be following the thread.

 

[clemsonfor]

That was me, but I also said to hone it, if you reread it, to hone you would need to pull the pistons out.

 

[normde2001]

If you can't catch a fingernail on the ring ridge, deglazing hone , rings, and pistons and good to go. I would also do rod bearings while there.

 

[Indirocz28]

Time for a little bit of an update. Received all of the parts from Hoye today.
Had my buddy come over with his hone and went to work on the cylinder walls. Turns out there was some ring ridge, however, the front cylinder just below that has a major low/worn area. The rest of the cylinder come out pretty good. Technically speaking these sleeves should be replaced. If it were a car or truck I was going to rely on daily, then I definitely would have replaced them. We are both confident, however, that they will be good enough for this old tractor, with new pistons and rings to probably work for many years to come barring any other unforeseen problems.

I hope to get her back going again by the end of the week, possibly able to use it this weekend perhaps!
Anyway, that’s the goal!

 

[winston1]

Just curious, did you possibly check ring end gap at different points up and down the cylinder?

 

[clemsonfor]

I thought that front cylinder looked pretty worn about mid way down.

 

[Indirocz28]

Just curious, did you possibly check ring end gap at different points up and down the cylinder?

Have not yet, plan to tonight.

Does anyone have the specifications for end gap, torque specs for rod bolts, spec and sequence for head studs?

 

[stsid1]

If you have a ridge at the top of the bore, that's what busted the rings and damaged the piston glands. If not replacing cylinder liners, you need to cut that ridge off with a ridge cutter or face possible damage to your new parts. If the low spots are in the ring contact area, you may get blowby.

 

[kenmac]

Have not yet, plan to tonight.

Does anyone have the specifications for end gap, torque specs for rod bolts, spec and sequence for head studs?

I can look them up for mine (3110) if you like. I have o idea if they would be the same as your's

 

[Indirocz28]

If you have a ridge at the top of the bore, that's what busted the rings and damaged the piston glands. If not replacing cylinder liners, you need to cut that ridge off with a ridge cutter or face possible damage to your new parts. If the low spots are in the ring contact area, you may get blowby.

The bores are actually wider at the top and taper down a bit farther down. The ridges came out respectively to the rest of the cylinder walls, except where that front cylinder area is worn.
I do not believe this caused the rings to break, as where the ridge was, is still above where the top ring of the piston stops.
I firmly believe the engine sat seized at one point in time. They took the head off to un stick it, used silicone and slapped the original HG back on, sent it on its way for several years, clogged coolant ports and all. Dummies.

It wouldn’t surprise me if there was still some blow by afterwards, but I paid $2,000 for this tractor, and don’t plan to put anymore money into it if this works well enough. It darn well should run better than it did before, that’s all that matters in this particular case.