YM226D Project

rScotty · Apr 1, 2021

bmaverick said:
What grade oil? 15W40 that is thick or SAE 30 being a tad thinner? 5W30 may be useless to test with wet.

I'd use the more viscous oil. Not too much; a couple of squirts ought to do it. There isn't a lot of room in the compression chamber of a diesel & you don't want to bend a rod.
Also give a little thought to oil as fuel. Hopefully this test will increase the compression - and there is a point at which lube oil and diesel fuel start to look similar to a diesel. If you can ignite it, chances are the diesel can too.
rScotty

tc197 · Apr 3, 2021

Ran the wet compression test today and got improved results - 350 psi in all three cylinders. So I went from 280-250-250 to 350-350-350. I think this demonstrates that the rings are not sealing well enough to maintain proper compression, however I'm not sure I can only blame the rings as there may be a secondary issue as well.

tc197 · Apr 7, 2021

Managed to squeeze the tractor into the overfilled garage. Hoping to get the head off and see what I’m working with in the next few days.

tc197 · May 5, 2021

Still here, just slightly delayed. Opening it up any day now.

Smokeonthewater · May 7, 2021

How much run time have you put on this thing? If it sat a long time, you might consider working it pretty hard for a few hours w good fuel and fresh oil... you may find that the compression numbers come up just from that....

tc197 · Jun 6, 2021

Behind schedule but making progress. I pulled the head the other day and got my first look inside. In general things appear to be in good shape. The only noticeable thing to me is that 1 valve is discolored compared to the others. I have 1 valve that is a greyish color and appears dry while the other 5 are darker and almost look wet. I'll try to post some pictures later.

California · Jun 7, 2021

tc197 said:
...1 valve that is a greyish color and appears dry while the other 5 are darker and almost look wet. I'll try to post some pictures later.

Sounds burned. Pour a little solvent in the intake and see if goes right through that one.

tc197 · Jul 16, 2021

Been working on the tractor a bunch and overdue for an update here.

After removing the head and getting my first good look at everything I decided I was going to pull the pistons and inspect the rings, sleeves, etc. Unfortunately everything I've found doesn't look good. I removed the oil pan to access the bottom end and remove the pistons and found huge chunks of metal and a ton of fine metal in the oil pan. Something exploded, although it's not clear what yet. I had pieces that were 1/4" wide and 2" long sitting in the oil pan. At this point I knew the work was only getting started and wouldn't be a quick fix.

I got the pistons out and found some damage on the skirts and a bit of wear on the middle piston/sleeve. Everything is accounted for so far and I haven't figured out what turned to shrapnel in my oil pan so I decided I just need to pull the engine completely and go through everything. Last night I split the tractor at the clutch housing and got it into two separate pieces. Following the manual instructions, next I will separate the front axle from the engine and I'll get it on a stand so I can continue disassembly and figure out what's damaged. Looks like this project is still just getting started.

bmaverick · Jul 16, 2021

tc197 said:
Been working on the tractor a bunch and overdue for an update here.

After removing the head and getting my first good look at everything I decided I was going to pull the pistons and inspect the rings, sleeves, etc. Unfortunately everything I've found doesn't look good. I removed the oil pan to access the bottom end and remove the pistons and found huge chunks of metal and a ton of fine metal in the oil pan. Something exploded, although it's not clear what yet. I had pieces that were 1/4" wide and 2" long sitting in the oil pan. At this point I knew the work was only getting started and wouldn't be a quick fix.

I got the pistons out and found some damage on the skirts and a bit of wear on the middle piston/sleeve. Everything is accounted for so far and I haven't figured out what turned to shrapnel in my oil pan so I decided I just need to pull the engine completely and go through everything. Last night I split the tractor at the clutch housing and got it into two separate pieces. Following the manual instructions, next I will separate the front axle from the engine and I'll get it on a stand so I can continue disassembly and figure out what's damaged. Looks like this project is still just getting started.

Do any of the parts in this 3T75HA rebuilt kit look to be a 1/4-in x 2-in part?