Valve adjustment

[Russ from MN]

I am past due on the recommended valve clearance check on our 2001 JD 4600, and I know I have seen a simple procedure on here before. It's a 4-cylinder Yanmar diesel, and has always run great, and I want to keep it that way. I can turn the engine over with a socket and U-joint and long extension, but it's not easy, so I want to minimize turning it. there are no timing marks that I'm aware of, so I will just be going by rocker position for piston location. I have seen in the past a procedure where you stop the engine in a certain position, adjust 4 valves, then turn it, and adjust the other 4 valves, that's what I'm looking for. I tried googling it and don't see the procedure I'm looking for. I have adjusted valves on many different kinds of engines, so I'm familiar with the procedure, just want to minimize turning it. Thanks!

 

[Janicholson]

Putting #1 on the TDC of compression allows adjusting that one then 1/2 turn and adjust the next in the firing order, 1/2 turn and the next, etc.
This is the most assured method I can recommend and only takes 2 complete revolutions. I do not know the 2 position turn procedure for that engine. Jim

 

[Dieseltech]

I do four cylinder engines this way that fire 1-3-4-2. Watch the valves ROCKING during the overlap period, exhaust valve JUST CLOSING and intake just STARTING to open on number 1 or 4 as they are at TDC together. When 1 is ROCKING set both valves on 4. When 4 is rocking set both on 1. Same applies to cylinders 2 and 3 as they are at TDC together also.

1-3 rocking,
2-4 SET.

Turn engine crank 180 degrees after setting a given cylinder then set the next one in firing order.
Same method works well on four cycle six cylinder engines too, 1-5-3-6-2-4, except the crank is turned 120 degrees.

 

[Jim.ME]

I am past due on the recommended valve clearance check on our 2001 JD 4600, and I know I have seen a simple procedure on here before. It's a 4-cylinder Yanmar diesel, and has always run great, and I want to keep it that way. I can turn the engine over with a socket and U-joint and long extension, but it's not easy, so I want to minimize turning it. there are no timing marks that I'm aware of, so I will just be going by rocker position for piston location. I have seen in the past a procedure where you stop the engine in a certain position, adjust 4 valves, then turn it, and adjust the other 4 valves, that's what I'm looking for. I tried googling it and don't see the procedure I'm looking for. I have adjusted valves on many different kinds of engines, so I'm familiar with the procedure, just want to minimize turning it. Thanks!

I expect that procedure is in the technical manual for your 4600. JD put it in many of their manuals.

Here is what is in a 2030 manual. I have not read the 4600 manual, so cannot say what it says. YMMV.

 

[Fritz Maurer]

Would like to hear the results. My guess is that little Jap engine is going to need little to no adjustment. They build better Diesels than the country of origin that invented them.

 

[Russ from MN]

Thanks fellows, for all the good advice! Yes, I don't expect them to be very far out of spec, but I'm worried about it. I will have to crawl underneath to turn the engine, my wife will watch the rockers, so we can stop in the correct position. I think I should take the loader off, so I can get closer to the engine, that's pretty easy to do.

 

[Dieseltech]

Thanks fellows, for all the good advice! Yes, I don't expect them to be very far out of spec, but I'm worried about it. I will have to crawl underneath to turn the engine, my wife will watch the rockers, so we can stop in the correct position. I think I should take the loader off, so I can get closer to the engine, that's pretty easy to do.

Try turning the engine with the alternator pulley nut while pushing on the slack side of the belt, I turn a lot of engines this way. Sometimes just bumping the starter switch will work too.

 

[Russ from MN]

Try turning the engine with the alternator pulley nut while pushing on the slack side of the belt, I turn a lot of engines this way. Sometimes just bumping the starter switch will work too.

Thanks, I'll try that!

 

[rustred]

I do four cylinder engines this way that fire 1-3-4-2. Watch the valves ROCKING during the overlap period, exhaust valve JUST CLOSING and intake just STARTING to open on number 1 or 4 as they are at TDC together. When 1 is ROCKING set both valves on 4. When 4 is rocking set both on 1. Same applies to cylinders 2 and 3 as they are at TDC together also.

1-3 rocking,
2-4 SET.

Turn engine crank 180 degrees after setting a given cylinder then set the next one in firing order.
Same method works well on four cycle six cylinder engines too, 1-5-3-6-2-4, except the crank is turned 120 degrees.

Exactly. All you need to know is what’s the running mates and a person can’t go wrong on any engine. And if you don’t know the running mates just write down the firing order and put the last half of numbers under the first half and you have the running mates for each cylinder. Just like the song, that’s the way uhh huh .