Engine question?

[tarheel96]

I just recently bought a tractor that was in the process of replacing a blown head gasket so the head was removed from the block. The tractor was covered and stored with the head removed for quite some time. My question to all you is what should I do to flush any dirt or junk that "could" have got done in the motor? Should I pull the motor apart and clean and reassemble to be on the safe side.What would you guys and gals do? Thanks

 

[Jerry/MT]

I just recently bought a tractor that was in the process of replacing a blown head gasket so the head was removed from the block. The tractor was covered and stored with the head removed for quite some time. My question to all you is what should I do to flush any dirt or junk that "could" have got done in the motor? Should I pull the motor apart and clean and reassemble to be on the safe side.What would you guys and gals do? Thanks

This is like someone asking a the question, "Why won't my tractor start?" without any factual info. The answer you get will be more conjecture that based on solid facts. Having said that, I'll venture an answer.

It depends on what the top of the block deck and the bottom of the cylinder head look like. f they are just dusty, wipe them off with mineral spirits check them for flatness, make sure the valves are good,and if good ,wipe out the bores and put it together. If they have light rust, plug the bores with rags, use a fine emery cloth and polish them, clean off any "rust dust", check for flatness and if good, reassemble. You might want to take the head in and get it checked out.
If you dismantle the whole engine you'll have to check all the bearing clearances, journals, etc and you're liable to get into some real $'s. for a little bit of normal wear and tear.Your dollars, your choice.

 

[tarheel96]

This is like someone asking a the question, "Why won't my tractor start?" without any factual info. The answer you get will be more conjecture that based on solid facts. Having said that, I'll venture an answer.

It depends on what the top of the block deck and the bottom of the cylinder head look like. f they are just dusty, wipe them off with mineral spirits check them for flatness, make sure the valves are good,and if good ,wipe out the bores and put it together. If they have light rust, plug the bores with rags, use a fine emery cloth and polish them, clean off any "rust dust", check for flatness and if good, reassemble. You might want to take the head in and get it checked out.
If you dismantle the whole engine you'll have to check all the bearing clearances, journals, etc and you're liable to get into some real $'s. for a little bit of normal wear and tear.Your dollars, your choice.

Thanks for the reply Jerry. My question is not how to clean the head or block of "normal wear and tear" as you put..but to clean the inside of a motor of possible dirt or debris. If I had a bore camera I would know for a fact but I dont. Could just draining the oil get everything out maybe? Thanks

 

[JRobyn]

I'd get the cylinder bores clean - no crud or any rust more than maybe a very light patina. Wipe all that out the best you can. Then take a shop vac with a crevice tool to the bores, especially the slight gap between the pistons and bores. Then blast this same area with compressed air. Finally, coat the bores with a light, solvent-type machine oil like Marvel Mystery oil and let it sit for at least a few minutes. Before you do the next step, be CERTAIN of how any timing marks on the crankshaft pulley and injection pump are aligned!!! And then turn the engine over gently by hand (crankshaft bolt) at least a few full turns. If there's any residual crap in the bores, the rings will push it up to the top of the bore and the oil will hold it there for you wipe out.

Of course, drain the crankcase into a suitable container so that you can inspect for any evidence that water/fuel/trash somehow got past the rings and into the oil/crankcase. If the head gasket went "badly" there may well be coolant that got past the rings and into the crankcase/oil. And there's a good chance that it overheated enough to warp the head, requiring resurfacing. Can the previous owner tell you? Or tell you if there were any other symptoms of crank/bearing problems like low oil pressure? If not, I'd be inclined to leave the bottom end alone.

 

[tarheel96]

I'd get the cylinder bores clean - no crud or any rust more than maybe a very light patina. Wipe all that out the best you can. Then take a shop vac with a crevice tool to the bores, especially the slight gap between the pistons and bores. Then blast this same area with compressed air. Finally, coat the bores with a light, solvent-type machine oil like Marvel Mystery oil and let it sit for at least a few minutes. Before you do the next step, be CERTAIN of how any timing marks on the crankshaft pulley and injection pump are aligned!!! And then turn the engine over gently by hand (crankshaft bolt) at least a few full turns. If there's any residual crap in the bores, the rings will push it up to the top of the bore and the oil will hold it there for you wipe out.

Of course, drain the crankcase into a suitable container so that you can inspect for any evidence that water/fuel/trash somehow got past the rings and into the oil/crankcase. If the head gasket went "badly" there may well be coolant that got past the rings and into the crankcase/oil. And there's a good chance that it overheated enough to warp the head, requiring resurfacing. Can the previous owner tell you? Or tell you if there were any other symptoms of crank/bearing problems like low oil pressure? If not, I'd be inclined to leave the bottom end alone.

This helps a lot JRobyn. From what the previous owner said was he would get some overheating after running the tractor with a finishing mower after some time of use. It sounded like after he got it good and hot and under a load the tractor would get to hot. He told me he wasnt 100% sure it was the headgasket... He did take the head to a machine shop but didn't get anything done due to the shop not being able to get the injectors out. The machine shop said that they need a special tool to get them out so they could work on the head. That was all he did with the head far as I know. He told me everthing else was running like a top.. I will try what you are talking about with the vac and air compressor in the pistons area. I will also keep my eyes peeled when draining the oil. Got my fingers crossed! Thanks

 

[tarheel96]

Here is a couple of pics of the top of the block. I am still learning this site so the pics might be wrong format or something.
The Tractor is a YM1900 Yanmar with a 2TR17 engine in it.
Engine Detail:
Yanmar 2TR17
diesel
2-cylinder
liquid-cooled
62.31 ci [1.0 L]


Bore/Stroke: 3.346x3.543 inches [85 x 90 mm]
Power: 20.6 hp [15.4 kW]
Rated RPM: 2400
Idle RPM: 800-2400
Starter volts: 12

 

[ericm979]

In addition to the good advice you got for cleaning the bores I'd check to make sure nothing fell down the pushrod tunnels or into the water jacket. Any dirt in the pushrod tunnels is going to end up in the oil. Once you get it running consider an oil change soon after just in case there's crud in it.

 

[Jerry/MT]

This helps a lot JRobyn. From what the previous owner said was he would get some overheating after running the tractor with a finishing mower after some time of use. It sounded like after he got it good and hot and under a load the tractor would get to hot. He told me he wasnt 100% sure it was the headgasket... He did take the head to a machine shop but didn't get anything done due to the shop not being able to get the injectors out. The machine shop said that they need a special tool to get them out so they could work on the head. That was all he did with the head far as I know. He told me everthing else was running like a top.. I will try what you are talking about with the vac and air compressor in the pistons area. I will also keep my eyes peeled when draining the oil. Got my fingers crossed! Thanks

Another thing to consider since you say the PO noted overheating while mowing. Check the radiator air side for clogging with dirt and chaff. That's a frequent cause for overheating.

 

[JRobyn]

^^Yes. The symptoms actually sound more like poor cooling air or water (or both) flow. This could be due to radiator/thermostat/water pump problems and not the head gasket. Or even just a loose fan/water pump belt! Since it is disassembled to this degree now, would probably be wise to pull out the radiator for a thorough inside and outside cleaning. If you can still find a "radiator shop" in your area! The thermostat may have been hanging partly closed. A replacement thermostat is cheap and good insurance. There's a chance that the water pump impeller is degraded just due to age or poor cooling system maintenance. This can usually be verified just by pulling the water pump and only the cost of a new gasket is involved if it is ok.

So the previous overheating MAY have not been severe enough to warp the head. I have no idea how prone 2-cyl Yanmar heads are to warpage. Some heads are really tough, others not so much. But since it's off anyway, no good reason NOT to have it checked and resurfaced if necessary.

If a machine shop doesn't have tooling to remove diesel injectors, you definitely DON'T want to use that machine shop!

 

[tarheel96]

Another thing to consider since you say the PO noted overheating while mowing. Check the radiator air side for clogging with dirt and chaff. That's a frequent cause for overheating.

Good thinking Jerry I will have some time this weekend to do a little work on the trator I hope. If I do I will take more pics so you guys can see the condition of the other parts. Thanks for your help!