Hello my 1401D started running rough sounds like it is missing and won’t pull a load . Did not get hot as I have a manual gauge . I used tractor one day for three hours ran fine next day started running rough no power . I’ve went through the fuel system no water in fuel .
1401D missing and running rough
- Thread starter Kstan
- Start date
bmaverick
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- Yanmar YM2610 ■YANMAR GURU■ EXTRAORDINAIRE
Kstan,
Your YM1401 has the 3T72SB engine. It's not a popular engine in the Yanmar lineup. Let's first look at the simple and easy things to rule out.
- Engine oil 5W30 for winter use or 10W30 normal season use.
- Fuel filter was replaced within the last 6 months or in the past 100 hours of use.
- Fuel bowl and o-ring replaced every 3rd fuel filter change.
- Fuel tank cleaned at least every 8 years or 5 years in hotter climates.
- Seafoam treatment used to keep the fuel system clean and the injectors unclogged.
Next level requires a few tools.
- Remove the hard fuel lines feeding the injectors, try not to bend the hard lines too much. Place a jug under each open end. Turn the engine over like you are starting it. Evaluate the amount of diesel fuel output being nearly equal in all three collection jugs. If not nearly equal, then the problem is with the fuel pump. Member thepumpguysc is an expert rebuilder and great turn around time for the work.
- Should the fuel in the jugs be near equal, then the fuel injectors have a problem. Our machines are 40+ years old. Injectors do wear over the years of use.
With all that said above covering the fuel system.
Now, does the exhaust send out black puffs of smoke or soot? Too much build up can ruin a diesel engine as the soot isn not burned off. Yanmar states for their engines not to idle for more than 10mins at a time. And not to long idle and then turn off the engine for storage as the soot build up of unburned diesel can in fact carbonize over the pistons and into the valve and ports. Seafoam treatment thru the thermo-start air intake port is a great help to clean this above 1600 running engine rpms.
You can also do an engine cylinder compression test to look for further troubles.
jeff9366
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- Kubota Tractor Loader L3560 HST+ ~~~~~~~~~~~~~ 3,700 pounds bare tractor, 5,400 pounds operating weight, 37 horsepower
Temporarily remove your air filter to check for adequate air flow.
Thanks for the reply ! Fuel flow out of the three injector lines is near equal injector spray pattern is good ,fuel filter just serviced with oring 10 30 oil for winter here . Tried running with air hose off still the same result . I have had this tractor for a year and half with no problems . Would contaminated fuel cause these symptoms? My fuel here looks like water not diesel stupid ultra lower sulfur here in cali
ponytug
Super Member
So, you are in California?
Contaminated fuel would certainly cause the issues. #2 (summer) diesel instead of #1 (winter) diesel also can make a big difference. Even a little bit of waxing (gelling) of your fuel will really ruin your day, and your engine's day. My bet is that bad/contaminated/summer fuel is what you have. If you can drain the fuel and use it elsewhere, I would do that. I would also go ahead and replace the fuel filter. A little bit of algae, or wax, can go a long way to causing issues by restricting the filter. If you can't drain and replace all of the fuel, I would get the engine, fuel lines, new filter, and fuel tank warm and keep it warm for awhile, and then start it up to see how it runs.
I think all older diesel benefit from fuel additives to bring the lubricity, and hopefully also the cetane levels up. Today's diesel is quite different compared to diesel twenty or forty years ago. I use Opti-lube Summer routinely at about 1.5x the minimum recommendation. It has gotten great reviews on its lubricity compared to other diesel additives, and it happens to be one of the cheapest additives at the recommended dosage (by a lot). I do add SeaFoam periodically to the fuel just to keep fuel lines and injectors spotless. I think that @bmaverick's suggestions are all good, and I can attest that carefully adding seafoam directly into an intake can work wonders on cleaning valves and rings up.
All the best,
Peter
Thank you ! I pulled the head off today to get a look the three smaller bolts were hand tight also found a intake air leak at the gasket as well as a crack in the manifold right by the back bolt so someone has been inside this tractor before me . I have owned it about a year and a half with no problems till now . Cylinders look good no scratches I had no blow by , I’m going to slam a head gasket on it do the heat cycle and re torque . Would air leaks play a roll in my problems ?
bmaverick
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- Yanmar YM2610 ■YANMAR GURU■ EXTRAORDINAIRE
These Yanmar engines have a certain way to put the heads back on and a 3 stage torque method. Do not, these tractors are build to JIS standards and from the Japan industries. Doing it the American way would only ask for trouble. It's another reason why Deere compacts made by Yanmar have lengthy service manuals too. I'll poke around for a 3T72 engine service manual or a 3T75 version because they are setup in that size of engine family.
OK the US domestic sold YM186 has the 3T72HA engine. The parts manual is all in English.
The John Deere JD670 has the 3TNA72 engine. The NA just means it has the first generation emission hardware added. The head is the same casting. TM1470 Technical Service Manual and CTM-3 is what you need to follow getting the head back on the engine.
Here's the engines covered in the CTM-3 manual.
OK, found the page we are after. Note to dip the cap-screw (bolts) in CLEAN engine oil before the torque down procedure.
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