L175 Valve adjustment

[Orange Tractors]

Hello, new Kubota owner here. I have a recently purchased L175 that sat for two or three years. I have change the fluid in the transmission with universal Hy-trans, changed engine oil Rotella (15w-40) and filter, replaced the fuel filter. I drained the old fuel from the tank and refilled with fresh offroad diesel, using Sea Foam to try to get the injectors cleaned up.

Just a couple of problems left: the valve cover leaks oil and it sounds like the valves need adjusting, but I can't find the specs for valve lash.

Thanks for any help,

Robert

 

[Orange Tractors]

Thanks for the help Vic.

 

[oldtown]

is there a part number for the gasket and what is TDC?

 

[Bulldog]

is there a part number for the gasket and what is TDC?

I would say that TDC means Top Dead Center.

 

[oldtown]

great that is very immportant. did the parts number for the gasket ever come up.

 

[handyman]

That also means top dead center on compression stroke.handy

 

[oldtown]

i am doing a valve adjustment and have a few questions?

the manual provides instruction on valve adjustment, it does not differentiate or make mention of intake vs exhaust valves until you get to the part about adjusting the decompression and then it says to adjust the exhaust valve to a different clearance than the instructions for regular valve adjustment.

how are you supposed to adjust the E.V. through the peephole?

are all the valves adjusted to the same clearance?


how many marks are on the flywheel? the manual makes reference to F1 and TC

i use the alternator bolt to turn the engine but which way do i turn it?

 

[Orange Tractors]

i am doing a valve adjustment and have a few questions?

the manual provides instruction on valve adjustment, it does not differentiate or make mention of intake vs exhaust valves until you get to the part about adjusting the decompression and then it says to adjust the exhaust valve to a different clearance than the instructions for regular valve adjustment.

how are you supposed to adjust the E.V. through the peephole?

are all the valves adjusted to the same clearance?


how many marks are on the flywheel? the manual makes reference to F1 and TC

i use the alternator bolt to turn the engine but which way do i turn it?

Oldtown,

I didn't have a manual when I adjusted my valves. I just took the valve cover off and turned the engine over by bumping the starter until both rocker arms for one cylinder were loose; Three of my vavles were extremely loose, on the order of .016-.018". Getting them set to .009" seemed to add about twice the horsepower it had before, (by the seat of the pants dyno).I used the figures that Vic provided and didn't mess with the decrompression adjustment.

Good Luck with yours, mine makes an excellent lawnmower.

Robert

 

[oldtown]

thanks , i spoke to the local kubota dealer mechanic and he gave me his version. now i am confused. he recommended not to use the flywheel mark and adjust intake when exaust starts to go dwon. adjust exhaust when intake starts to come up.

i did mine with flywheel on TDC and adjusted all 4 with flywheel in that position. was that correct?

 

[aquaforce]

thanks , i spoke to the local kubota dealer mechanic and he gave me his version. now i am confused. he recommended not to use the flywheel mark and adjust intake when exaust starts to go dwon. adjust exhaust when intake starts to come up.

i did mine with flywheel on TDC and adjusted all 4 with flywheel in that position. was that correct?

Maybe I can be more clear as to what he is saying, he is right. No you can't adust all at TDC.

Sometimes that confusion is intentional. Can't blame a guy for drumming up work, but what they do is make an explanation that is confusing so a person will give up, bring the work to the mechanic and PAY!!! They need a paycheck too.

Anyway, the TDC and F1 thing has to do with timing the injector pump. There is F1 and F2 on the L175 since there are two cylinders. Then there is a TDC for both cylinders. How is that for confusion.


Well......................CAPTAIN CANDLE WAX will divulge this service tip that will try to simplify the valve adjust procedure.
It gets challenging to find material, data and engine information with most any engine as it is these days so the procedure that is used by crew chiefs and engine builders for ANY camshaft and profile is what I use. This procedure works with the natural events of the engine regardless of how many cylinders, how radical the engine or what kind of fuel it burns, internal combustion only.


Rotate the engine in its normal direction of operation and apply this procedure to one cylinder at a time. Firing order and all other parameters are irrelavant. Just do one cylinder at a time using this sequence of valve events and you can adjust any engine in the world.

INTAKE VALVE --- CLOSING ----- ADJUST EXHAUST VALVE
EXHAUT VALVE ---OPENING ----- ADJUST INTAKE VALVE

The opening and closing should be observed at the very begining of the valve movement (just beginning to open or just beginning to close) to indicate the stop and adjust point. Just keep turning the engine over until this specific point happens and the valve is on the heel for adjustment.

Good luck

 

[Orange Tractors]

Maybe I can be more clear as to what he is saying, he is right. No you can't adust all at TDC....

Rotate the engine in its normal direction of operation and apply this procedure to one cylinder at a time. Firing order and all other parameters are irrelavant. Just do one cylinder at a time using this sequence of valve events and you can adjust any engine in the world.

INTAKE VALVE --- CLOSING ----- ADJUST EXHAUST VALVE
EXHAUT VALVE ---OPENING ----- ADJUST INTAKE VALVE

The opening and closing should be observed at the very begining of the valve movement (just beginning to open or just beginning to close) to indicate the stop and adjust point. Just keep turning the engine over until this specific point happens and the valve is on the heel for adjustment.

Good luck

Aquaforce,

Very clear, easy to understand instructions.

This should help a lot of people to adjust valves. Now the biggest problem will be to find a feeler guage that is the correct thickness.

Robert

 

[traildust]

You, my friend, are indeed one crazy son of a bitch ........

 

[oldtown]

Maybe I can be more clear as to what he is saying, he is right. No you can't adust all at TDC.

Sometimes that confusion is intentional. Can't blame a guy for drumming up work, but what they do is make an explanation that is confusing so a person will give up, bring the work to the mechanic and PAY!!! They need a paycheck too.

Anyway, the TDC and F1 thing has to do with timing the injector pump. There is F1 and F2 on the L175 since there are two cylinders. Then there is a TDC for both cylinders. How is that for confusion.


Well......................CAPTAIN CANDLE WAX will divulge this service tip that will try to simplify the valve adjust procedure.
It gets challenging to find material, data and engine information with most any engine as it is these days so the procedure that is used by crew chiefs and engine builders for ANY camshaft and profile is what I use. This procedure works with the natural events of the engine regardless of how many cylinders, how radical the engine or what kind of fuel it burns, internal combustion only.


Rotate the engine in its normal direction of operation and apply this procedure to one cylinder at a time. Firing order and all other parameters are irrelavant. Just do one cylinder at a time using this sequence of valve events and you can adjust any engine in the world.

INTAKE VALVE --- CLOSING ----- ADJUST EXHAUST VALVE
EXHAUT VALVE ---OPENING ----- ADJUST INTAKE VALVE

The opening and closing should be observed at the very begining of the valve movement (just beginning to open or just beginning to close) to indicate the stop and adjust point. Just keep turning the engine over until this specific point happens and the valve is on the heel for adjustment.

Good luck

thanks for the advice, you made it alot more simple. i have got the tractor back up and running... well almost. i adjusted the valves, but i think i got the order wrong. the tractor drops 1000 rpm when i engage the mower. it also sounds different, it does not CLACK like it used to. i adjusted in this order from the front of the machine.

Intake - Exhaust - intake - exhaust,

i remember, now, from doing the valves in the mercedes that the order was

intake - exhaust - exhaust - intake.

what is the correct order ??

waiting for the engine to cool and the rain to stop.

thanks DA

 

[eserv]

Turn the engine either direction until one valve is just closing and the other is just opening on the cylinder you want to adjust the valves on. then turn the engine one complete turn(either direction) and then adjust the two valves for that cylinder. repeat for all the other cylinders. this way you are adjusting the valves at the top of the compression stroke just as the cylinder is starting the firing stroke. ( it is good practice to always turn an engine it's running direction)
But sometimes it's just more convenient to turn them backwards!
Ed

 

[oldtown]

ok i have adjusted and adjusted these valves.

the engine still bogs down easily and lacks powers.

i am going to use the TDC method that is provided in the manual.

 

[aquaforce]

Aquaforce,

Very clear, easy to understand instructions.

This should help a lot of people to adjust valves. Now the biggest problem will be to find a feeler guage that is the correct thickness.

Robert

Good to hear. I hope it helps others some.

You, my friend, are indeed one crazy son of a bitch ........

Sometimes I think I am crazy for getting into this kind of career.

 

[oldtown]

Turn the engine either direction until one valve is just closing and the other is just opening on the cylinder you want to adjust the valves on. then turn the engine one complete turn(either direction) and then adjust the two valves for that cylinder. repeat for all the other cylinders. this way you are adjusting the valves at the top of the compression stroke just as the cylinder is starting the firing stroke. ( it is good practice to always turn an engine it's running direction)
But sometimes it's just more convenient to turn them backwards!
Ed

when you say turn engine one complete turn, what do you mean? one complete revolution on the flywheel?

 

[eserv]

Yes, I mean one complete turn of the flywheel. When the valves are "rocking" ( one just closing and the other just starting to open) the piston is at Top Dead Center (TDC) Turn it one complete turn and it is again at top dead center but this time at the firing position, both valves are completely closed at that position and can be properly adjusted.
Ed

 

[oldtown]

Yes, I mean one complete turn of the flywheel. When the valves are "rocking" ( one just closing and the other just starting to open) the piston is at Top Dead Center (TDC) Turn it one complete turn and it is again at top dead center but this time at the firing position, both valves are completely closed at that position and can be properly adjusted.
Ed

Ok i did this and i think the valves are adjusted correctly. When the valves were rocking i made one more complete turn back to TDC on the respective cylinders, there are only two, i adjusted to.008. the machine sounds good but still lacks powers when climbing hills and when PTO is engaged.

just to give an example, when the tractor is running standing still i can adjust the throttle either by hand or with my foot and the engine is slow to respond and takes a while to come up to RPM. Before i messed with the valves the engine was very responsive.

i also bled the fuel line while running and not running thinking that air was in the line.

it may still be the valves but i wonder if something is up with the fuel delivery system.

thanks DA

 

[oldtown]

FYI , on TC of each cylinder i adjusted both valves at the same time. is that correct/