L175 Valve adjustment

[oldtown]

i guess everyone is out using their tractor today instead of trying to figure out why it does not run correctly.

i have bled the lines as instructed in the article on this site. i started it up and it ran fine and then all of sudden it cut off like it was out of fuel. cranked right back up. engine was going from 800 rpm to 1500 without touching a thing then cut off again. started back up and runs fine . engine sounds great but lacks power.

IN 5th gear and PTO engaged in LO, the engine drops to 900 rpm and takes forever to gain momentum. if i am on a hill it wont go and has to be saved from dieing by depressing the clutch.

 

[eserv]

I don't believe your problem is valve adjustment. If the valves were enough out of adjustment to effect power so drastically you would have extreme difficulty getting the engine started.

 

[oldtown]

what in the world is going on. tractor starts good. it ran fine before i "Fixed IT"

 

[eserv]

Maybe you are like my ex-fatherinlaw, He fixed lots of things until they were broke! Seriously though, does the tractor idle smooth? Does it smoke under load? Is there some other parasitic load? ( three point hitch adjusted to high, loader hoses not properly attached etc?)

 

[oldtown]

it does idle smooth. it does not smoke under load. a little smoke when i start but that is it. but it wont take a load either. throttle is slow to respond and once again when i activate the PTO it cant handle it and the RPMs drop off.

not sure if it makes a difference but i did replace the fuel filter with one from auto zone the numbers were cross referenced. it fit and is the same size as the original.

i have adjusted the valves using the TDC method that you recommended, when the valves were rocking at TDC, i spun it around another complete turn to TDC and adjusted.

i also used the method that aquaforce recommended. which the first part is at TDC but the second part is not.
INTAKE VALVE --- CLOSING ----- ADJUST EXHAUST VALVE
EXHAUT VALVE ---OPENING ----- ADJUST INTAKE VALVE

using both methods tractor ran about the same, seems like the aquaforce method had a LITTLE more power, ran louder, the reaction time of the throttle seems better.

one more thing i noticed when i had them adjusted on the TDC method. i noticed that you could hear the pull on the engine when i turned the key on and off. it was slight but you could hear it. it seems like hitting the key for the charging system would not have any affect. The TDC method sounded smoother.

when i bled the fuel system, with the engine running, i loosened #1 at hte injector and of course fuel went everywhere, the engine stayed alive and did not falter. however as soon as i broke the seal on #2 cylinder at the injector
the motor quit.

that is all the details i have.

 

[eserv]

Sounds like one or more of your delivery valve holders are loose. Try loosening the injector lines at the pump and tightening the fitting just below the injector line nuts. this is the delivery valve holder and can cause similar problems to what you have if they are loose. it is easy to loosen them by mistake when you are removing the injector lines. Kubota have a locking device on them but it isn't strong enough if you have stubborn fittings. Just tighten them down firmly and reinstall the lines.
Ed

 

[Orange Tractors]

it does idle smooth. it does not smoke under load. a little smoke when i start but that is it. but it wont take a load either. throttle is slow to respond and once again when i activate the PTO it cant handle it and the RPMs drop off.

not sure if it makes a difference but i did replace the fuel filter with one from auto zone the numbers were cross referenced. it fit and is the same size as the original.

i have adjusted the valves using the TDC method that you recommended, when the valves were rocking at TDC, i spun it around another complete turn to TDC and adjusted.

i also used the method that aquaforce recommended. which the first part is at TDC but the second part is not.
INTAKE VALVE --- CLOSING ----- ADJUST EXHAUST VALVE
EXHAUT VALVE ---OPENING ----- ADJUST INTAKE VALVE

using both methods tractor ran about the same, seems like the aquaforce method had a LITTLE more power, ran louder, the reaction time of the throttle seems better.

one more thing i noticed when i had them adjusted on the TDC method. i noticed that you could hear the pull on the engine when i turned the key on and off. it was slight but you could hear it. it seems like hitting the key for the charging system would not have any affect. The TDC method sounded smoother.

when i bled the fuel system, with the engine running, i loosened #1 at hte injector and of course fuel went everywhere, the engine stayed alive and did not falter. however as soon as i broke the seal on #2 cylinder at the injector
the motor quit.

that is all the details i have.

It sounds to me like you have the vavles adjusted okay; at least for now, but you have further problems. It is natural to feel that you have screwed up the last thing you worked on, and to suspect that.

I'm not really a diesel mechanic, but the last paragraph tells me you aren't getting any fuel to the #1 cylinder, and are only running on #2. You are getting fuel to the #1 injector; but it is not getting into the cylinder. I would either get that injector tested and repaired, or replace it; they aren't that expensive.

Robert

 

[oldtown]

well i tried the old take it apart and put it back together. also i left the fuel line on the #1 cylinder that was apparently blocked and took the line off the #2 cylinder which was not and she started right up. so we are now operating on all cylinders!! yeah. must have been a little bit of trash.

now for one last question.

which valve adjustment do i use? the TDC method or the aquaforce method. ?

thanks for all the trouble shooting help. i will post pics asap.. now i can move on to redoing the decals.

 

[Orange Tractors]

Oldtown,

Either method will work, as long as you understand what you are trying to accomplish. When you adjust valve lash on an engine with mechanical lifters; what you are doing is setting the amount of clearance, or slack, that is built into the system. If the rocker arm is too tight, when the engine heats up do to combustion temperatures the valves will not fully close, causing loss of compression, lack of power, and maybe burning valves and seats. If the rockerarm is too loose, on the intake you won't get enough air to allow the fuel that is injected to fully combust; if the exhaust valve is too loose you will not get all the burned fuel out of the cylinder, also causing incomplete combustion, because there is not enough oxygen available to burn the next charge of fuel.

As Vic stated in his reply to my first post on this subjectl valve lash, (or clearance) is .007" to .009" with the engine cold.

Here is how I adjusted my valves.

After taking the valve cover off, I turned the engine over a couple of times just to be sure everything was moving like it should.

Then I bumped the starter until both rocker arms on the front cylinder were loose, indicating that the piston was at top dead center of the compression stroke.

I then measured the clearance between the rocker arm and the valve stem. (All of my valves were too loose, one was at about .011" the othe three were around .016"-.018").

Loosen the lock nut on the adjuster, then turn it in until it lightly touches your feeler guage.

Tighten the lock nut and do the other valve on that cylinder. Very important that this gets tightened.

Repeat the operation for the other cylinder, then put the valve cover back on.

After replacing the valve cover I adjusted the decompression linkage, to make sure that it didn't affect anything. (the knob on mine is broken off, I didn't replace it. I only use this tractor for lawn mowing.)

That is basically it. Like I said; by adjusting the valves on mine, it seemedlike I had twice the available horsepower and torque.

I know that it is frustrating to work on a piece of equipment, and not have it come out right the first time. Perseverance and attention to detail will obtain the desired results.

Good luck,

Robert

 

[meanjean]

Can someone speak to this last question?

 

[eserv]

Kinda OK except just because the rockers are loose doesn't mean the cam is in the ideal position to be adjusted.

 

[aquaforce]

Can someone speak to this last question?

I hope you saw my post on page two of this thread.

Are you talking about the TDC reference in that last question? TDC is only a reference point if the camshaft heel and toe profile are going to be followed for specific adjustment points in the firing order. Following the procedure I listed ONLY follows the heel and toe of the cam and the adjustment procedure can be done on any cylinder in any order.