# YM1700 engine



## efren chua (Jun 4, 2006)

Hello,
My YM1700 Yanmar 2 cyl diesel was recently overhauled with new cylinder liners, rings, main and con bearings, new valve seals and new cylinderhead gasket. After running for 2 hours oil started to come out of the exhaust, it was opened up again and replaced with a new set of rings, after running for 2 hours oil was coming out again of the exhaust, it was running fine and not overheating, very slight white blue coming out of the exhaust. What could be the problem? Please help.
Thanks,
Efren Chua
[email protected]


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## Live Oak (Dec 22, 2003)

Have you done a compression check?


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## Live Oak (Dec 22, 2003)

I meant to ask, just to clarify. Exactly how much oil are you talking about coming out of the exhaust?


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## Archdean (Jul 15, 2004)

Been working on engines all my life!!

Blue= oil
White= water
Black = fuel

Your a great deal smarter than me if you can diagnose the shades of color with pinpoint accuracy!!

I too would like to know what you mean by "oil coming out of the exhaust"

With new liners and rings , you are likely to see most anything !!


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## mark777 (Jul 23, 2004)

efren,

I'm going to assume that you are not too familiar with the mechanics of diesel engines. Maybe the simplest approach would be to check and make sure your crankcase is venting properly. 

There should be a breather attached to your valve cover. It is filled with stainless steel wire mesh on top of a dimpled plate and "O" ring, and has a rubber down tube that runs below the tractor frame. If the breather is dirty or clogged it will produce sufficient pressure and pump oil passed your rings, into the combustion chamber, mix with fuel and create dark blue smoke and diesel slobber (oil dripping from the exhaust pipe). Cleaning the entire breather system, with denatured alcohol or carb spray MAY be a quick fix and allow the system to vent excessive pressures. 

After cleaning the crank case breather assembly, running the tractor to normal operating temperatures, and you still see excessive smoke, remove oil filler cap from the valve cover and see if you have blow-by coming from the valve cover. If it is producing distinctive puffs of smoke, alternating between cylinders, then I would be suspicious of the piston ring gaps being too wide. Although the engines are quite simple in their design and operation...you have 4 ring groves per piston and 4 rings per cylinder, so the placement of the rings and each individual gap is critical. Your model also produces a 19.5 to 1 compression ratio per cylinder and can easily create systemic pressures mechanics tend to overlook.

One last thought: Try using your tractor with a heavy implement (box blade, rotary cutter) for 4-6 hours under heavy load, and allow the new engine parts to break in. Chances are good everything internally, including the rings have not completely seated to normal tolerances and the smoke will eventually clear up. The Yanmar YM1700 and YM2000 is quite possibly the best, well supported and most popular two cylinder tractors the company ever produced.

Good Luck.


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## efren chua (Jun 4, 2006)

*yanmar ym1700*

Hello,
Running the engine, oil is dripping out of the exhaust manifold with the muffler removed. I run the engine at a steady speed of 1900 rpm oil is dripping out a drop about every 15 seconds each drop is small the size of a tear drop. I checked the breather with the engine running no oil or smoke is coming out and the back pressure is very slight. The machanic opened up the breather and cleaned it before the engine was run. The second time the engine was opened, we saw that one of the piston top was wet with oil and the other one was dry. The ring that was put in has a gap of .010".
Thanks,
Efren Chua


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## Archdean (Jul 15, 2004)

You either have a broken ring (rings) or a deeply scored sleeve and or all four rings are aligned!! In any event "It ain't right", somebody goofed!!


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## efren chua (Jun 4, 2006)

*Ym1700*

Hi, 
The liners are brand new and the rings are brand new. The second time it was opened up the ring gap are not lined up,
but we installed a brand new ring again thinking it might solve the problem, but it did not.
Hello Mark777 I tried to send e mail to you but can't get through.

Thanks,
Efren Chua


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## Live Oak (Dec 22, 2003)

I am thinking that you may have a bad or leaking fuel injector. This can give you the appearance of oil dripping out as it accumulates in the offencing cylinder. Can you pull the injectors and have them bench tested? If you have a badly leaking injector, this can cause some serious problems if not immediately fixed such as dilluting the oil with fuel, washing down the cylinder walls with fuel and damaging the rings, pistons, and liners. 

I agree with Mark, check the crankcase breather and ensure it is not obstructed. There will be a small amount of vapor/smoke coming out of the crankcase vent tube. I large amount would indicate ring blowby and loss of compression. I think this would be unlikely so soon after replacing them although it does happen. 

Anyhow, just wanted to follow up and throw out a few ideas to look at. Let us know how things go.


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## efren chua (Jun 4, 2006)

*YM 1700*

Hello,
Thanks for the info, I'll remove the two nozzles and have them calibrated or replaced if needed. I'll let you know if this will correct the problem. Really appreciate your help.

Hello Mark did you receive my reply today?
Thanks,
Efren Chua


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## mark777 (Jul 23, 2004)

Sorry Efren,

I did send you an Email but did not get your reply.

Mark


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## PcDoc (Jun 4, 2021)

Live Oak said:


> Have you done a compression check?


How Many Pounds Compression Should It Make?


Live Oak said:


> Have you done a compression check?


How Many Pounds Compression Should It Make/Show On A Compression Pressure Test Gauge?


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## PcDoc (Jun 4, 2021)

mark777 said:


> efren,
> 
> I'm going to assume that you are not too familiar with the mechanics of diesel engines. Maybe the simplest approach would be to check and make sure your crankcase is venting properly.
> 
> ...


How Many Pounds Compression Should It Make/Show On A Compression Pressure Test Gauge?
The ( 1700 model also produces a 19.5 to 1 compression ratio per cylinder ) 
I Don't Understand as In As In The Difference Of Pounds Compression? 
Pls. Explain.


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## bmaverick (Feb 20, 2014)

PcDoc said:


> How Many Pounds Compression Should It Make/Show On A Compression Pressure Test Gauge?
> The ( 1700 model also produces a 19.5 to 1 compression ratio per cylinder )
> I Don't Understand as In As In The Difference Of Pounds Compression?
> Pls. Explain.


Not sure if anyone from this old 2006 thread would respond. One member died a few years ago. Another no longer has a Yanmar. 

Do you have a YM1700 and need to know the compression?


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## PcDoc (Jun 4, 2021)

bmaverick said:


> Not sure if anyone from this old 2006 thread would respond. One member died a few years ago. Another no longer has a Yanmar.
> 
> Do you have a YM1700 and need to know the compression?


Yes I Think I Found It Bu Not Sure..... 400Lbs to 600lbs


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## bmaverick (Feb 20, 2014)

PcDoc said:


> Yes I Think I Found It Bu Not Sure..... 400Lbs to 600lbs


Do you have the YM1700 Parts Manual too? You can get it for FREE.


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