Valve lash adjustments

yugo · May 14, 2005

Valve adjustment on a Farm Pro 2425 with a Y385 engine, 300 hour preventive maintenance on a rainy afternoon, and this is what we found. The book that came with the tractor said that adjusting the valves was a three step procedure. ( I can relate that to a 3 can project) The first can was to remove the valve cover and locate top dead center on number one. I found the marks on the fly wheel, and also on the front dampener pulley. Can #2 is to adjust the valves. Number one - A-OK. The book says to rotate engine crank shaft 180 degrees, and check number 3 cylinder. Somewhat tight. The book says rotate the crank shaft 180 degrees to cylinder number 2. Valve adjustment here waaay tight. Somethings wrong! Now we see it must be Can #3 step. Stop and recheck top dead center. Check that we're turning the engine the correct way. Still the cam shaft geometry is off. Can #4 - Stop and think about it, to find what's wrong. In the bottom of this can, we found the answer. The cam shaft dials in at 240 degrees, instead of the 180 degrees. At 240 degrees of crank shaft rotation per cylinder, the valve adjustment came out A-OK. Has anyone else had this experience?
P.S. Not just anyone can take a 3 can job and stretch into a 6 pack job! Yugo

JINMA224XR · May 14, 2005

Hello Yugo,

We had an extensive discussion on Valve Adjustment in the Y380T Engine section at "NYTO FORUM SITE".

You might find it interesting to read.

Have a nice day,
Joe

F100Panel · May 16, 2005

I have a little easier on the brain method for adjusting the valves but admittedly it requires more time & turning of the engine.. I work 1 cylinder at a time. When I see one valve start to open as I turn the crank, I know the other valve on that cylinder is in the closed position/proper time to adjust. Takes longer but no brainpower required... Just my lazy method for adjustment/likely not the best/easiest... /forums/images/graemlins/smirk.gif

schmalts · May 16, 2005

Heres what you do. While rotating the engine in the normal direction (crank engine to see what that is, follow these steps.
when the exhaust valve is just starting to open adjust the intake. when the intake valve is just starting to close, adjust the exhaust. This will have the valves checked at base circle

johnk · May 16, 2005

That's how I do mine. It is much simpler, quicker and runs fine.

schmalts · May 16, 2005

( I have a little easier on the brain method for adjusting the valves but admittedly it requires more time & turning of the engine.. I work 1 cylinder at a time. When I see one valve start to open as I turn the crank, I know the other valve on that cylinder is in the closed position/proper time to adjust. Takes longer but no brainpower required... Just my lazy method for adjustment/likely not the best/easiest... /forums/images/graemlins/smirk.gif )
You do not want to do it that way, there is some overlap in valves and if you do the intake when it is just starting to open you will be adjusting the exhaust when it is still open or just barely closed.

F100Panel · May 17, 2005

Shmaltz- TRUE/AGREED/just starting to open should be valve basically open. To the human eye ( especially an older eye..) The valve has to be REALLY open to see it... & also not mentioned, the push rod of the other valve has no pressure on it & you can spin it with your finger freely. THANKS /forums/images/graemlins/wink.gif for getting me to fully explain.... & Actually, watching for the open valve to begin closing to adjust the other valve is a darn good idea too....

thingy · May 17, 2005

Which valve is which?,,some require different gaps,[exhaust/intake],if both the same than no problem,like my 254,,but pretty sure some 204's are different,as probably are others. thingy

awlchu · May 17, 2005

A trick I learned working on my motorcycles is to buy a "go-nogo" step feeler gauge. Each blade is precision grounded with the tip being .001" less than the body of the blade. Typically a good set will have a .024/.026" combination on one blade.

Thus the .024" should fit while the .026" should not fit. Helps with the guess work of settting the gaps.

schmalts · May 17, 2005

Look to see what port the valve aligns with better. The one in line with the intake port is the intake and so on.

thingy · May 17, 2005

What if you can't tell after looking at the ports? Take the head off,,,or what?? thingy

johnk · May 17, 2005

look at the exhaust manifold and where the enlarged part of the manifold for that cylinder connects to the head thats the exhaust port and vice versa.

JINMA224XR · May 17, 2005

( What if you can't tell after looking at the ports? Take the head off,,,or what?? thingy )

Hey Dick,

It sure would be nice if Harry would hurry up and post his Valve Adjustment GuideBook. /forums/images/graemlins/smile.gif

Maybe he has taken his head off to figure out which is which,, /forums/images/graemlins/smile.gif,, Just Kidding Harry. /forums/images/graemlins/smile.gif

One of these days we're all going to get this valve adjustment thing down correctly.

Get Your Tractors Running &
Have a nice day,
Joe /forums/images/graemlins/cool.gif

thingy · May 17, 2005

I've looked,,,and can't for sure tell which is going to which valve,,,,must be another way to tell???,,,or verify???,,,without taking head off???? Some motors have different gaps for intake and for exhaust valve lash,,,,,wouldn't want to gap one way to tight and other way to loose,,,,now would we???? thingy

JohnS · May 17, 2005

Boy, this sounds very familiar... /forums/images/graemlins/wink.gif Normal engine rotation... exhaust-open/close, followed quickly or partial overlap by intake open/close, noticable delay for compression/power stroke, and exhaust starts again. Unless you can't figure out which two valves go to what cylinder.

thingy · May 17, 2005

So John,,,which valve is it on the motor???,,,from raditiator,,,1st valve to first cylinder is ?,,,,,which would make the second valve ?,,,,,,thanks for telling us how the 4 cycle/stroke works though,,,,thingy

JohnS · May 18, 2005

Sorry Dick, we spared enough on this topic already, in a different forum. Welcome back to TBN.

schmalts · May 18, 2005

( I've looked,,,and can't for sure tell which is going to which valve,,,,must be another way to tell???,,,or verify???,,,without taking head off???? Some motors have different gaps for intake and for exhaust valve lash,,,,,wouldn't want to gap one way to tight and other way to loose,,,,now would we???? thingy )
I think it's time that you broke down and paid someone to do this for you. No offense but it sounds like your in over your head.

greg_g · May 18, 2005

( can't for sure tell which is going to which valve,,,,must be another way to tell??? )
I believe I posted this YangDong diagram before, but maybe one more time will help. On the Y380/385, part #10 is the exhaust valve and #32 is intake. Left side of the diagram is the radiator side.

Don't know if the photo JohnK uploaded is applicable to your tractor though Richard, cuz I'm pretty sure TY290/295 is not a YangDong engine.

//greg//

thingy · May 18, 2005

Scmaltes,,,so you know which is which??? so,let us know,,,which one is first valve back from raditiator,,intake or exhaust,??
I know,,have done it,,researched it,and could tell you if you don't know,,,just trying to let others know that if there valve settings are different for intake and for exhaust,they need to know which is which after taking valve cover off,,and there is a real easy way to tell,,,,my 254 valves are both set at same gap,,but others are different,,so let me know if I can help. the thing