YM155D Compression?

[BPoy]

Does anyone know what the compression should be for a YM155D with a 2TR13A engine?
I’ve had this tractor for almost 40 years with no problems other than changing the head gasket a couple years ago and it fired right up after I put it back together. I was cutting in the spring and it stalled out in the field and I haven’t been able to get it started again. It cranks good but won’t start. I’ve changed the fuel, the fuel filter, and bled it all the way to the injectors every time. Also, I cleaned the injectors.

I pulled the injectors and attach them to the fuel lines and they’re spraying. I pulled out one of the injector nozzles and hooked up a compression gauge to the injector and put it in the engine and it’s showing 250 and 260 in each cylinder respectively, without any droppage from leakage. I also reset the rocker arms/valves about 20 times and they all seem to be correct at .0006.
Any suggestions on what to check next would be appreciated since I just broke the fuel injector flange and a rocker arm/valve cover stud —if anybody knows where to get those cheap.

 

[winston-HT]

I would trust this old knowledgebase article put about by Aaron from the old Hoye tractor group. https://web.archive.org/web/2017082...actor.com/support/knowledgebase.php?article=7

You may have put to many zeroes in your valve setting. You are showing 6 ten thousands instead of 6 thousands.

 

[BPoy]

Thanks Winston. It didn't say what Yanmar engine it was referring to so I assume that compression (550-640) is accurate for my YM155D with a 2TR13A engine. I got a true compression adapter coming from Hoye to double check my compression. Do you know if a bad governor could cause it to crank buy not start? --Bob

 

[winston-HT]

I do believe 250-260 is low , whether 550-640 is exactly right I don't know, but much closer than the low numbers. If you are getting a good spray pattern with injectors I think that might rule out a bad governor as far as not starting.

 

[bmaverick]

Thanks Winston. It didn't say what Yanmar engine it was referring to so I assume that compression (550-640) is accurate for my YM155D with a 2TR13A engine. I got a true compression adapter coming from Hoye to double check my compression. Do you know if a bad governor could cause it to crank buy not start? --Bob

If you take the plate off, you can see if the pin-hole on the rod is in the right place.

1st watch the video Matt made,

Rick made this video as well. His is a YanDeere. LOL

 

[BPoy]

If you take the plate off, you can see if the pin-hole on the rod is in the right place.

1st watch the video Matt made,

Rick made this video as well. His is a YanDeere. LOL

Thanks for the videos. I got it started today but I don’t know how or what I did other than resetting the rocker arms 1 million times. But now I got oil pouring out the bottom that I assume is the rear main seal. So I’ll be posting a new thread asking how to replace that but I’m wondering if any of this is related that would cause the rear main seal to go before I even got it moving?

 

[winston-HT]

Is your oil level staying constant?

 

[BPoy]

I thought it was staying the same level the first couple times I got it started but the last time I started it I let it run for two minutes and it looked like the oil level dropped a quart. I put synthetic 10-30 oil in. It’s coming out between the block and the bell housing for the flywheel. What is that a sign of if oil level does or doesn’t drop?

 

[bmaverick]

I thought it was staying the same level the first couple times I got it started but the last time I started it I let it run for two minutes and it looked like the oil level dropped a quart. I put synthetic 10-30 oil in. It’s coming out between the block and the bell housing for the flywheel. What is that a sign of if oil level does or doesn’t drop?

Just like modern vehicles with a PCV on the engine, the Yanmar diesel engines have vent tubes. You need to remove the engine vent tube and purge out the grime in there. Mud wasps love to plug it up.