522xi engine problem.

[toma 12]

Hi all..I have a Toro522xi with a Kohler ch22s twin-v engine. I was having problems with loss of power, overheating, and an oil leak. I took the engine out. Replaced the head gaskets, valve stem seals, rear crank shaft seal ( was the oil leak). The engine was caked with oil and dirt under the shroud which I believe is why it was heating up.

 

 When I reinstalled the engine it seamed to be running ok. Had power back and I got about a half hour of grass cutting then it started to run rough and lost most of its power.

 

I took off the air cleaner and it appears the carburetor is pushing out instead of sucking in. I never noticed this before.  It will idol very low cautiously and steady but the more I up the throttle the more vapor, exhaust or whatever it is starts coming from the carburetor and it starts running very rough. Also noticed dark smoke from the exhaust and one spark plug is covered with black soot.

 

   I took the valve covers off and the valves seem ok. Seems to have the right spark.

What would cause vapor or exhaust to be pushing out of the carb?

Any Ideas would be greatly appreciated.

[RED-Z06 2,221]

Are you running 10w30?  The wrong oil or a bad hydraulic lifter can hang a valve open

[kpinnc 12,075]

I've seen similar with Vanguard V twins. Not the same, but similar. The head gaskets always are a weak spot. Some of the thinner sections tend to not seal well or break entirely, and combustion pressure bypasses into the crankcase. That can lead to pulse fuel pumps that overflow the carb bowl. Not to mention blowing oil into the breather, and eventual oil seal failures anywhere on the engine. 

 

1 hour ago, RED-Z06 said:

The wrong oil or a bad hydraulic lifter can hang a valve open

 

What's a good way to check if those hydraulic lifters are bad? I have a Command that ticks like an old watch... 

[RED-Z06 2,221]

1 hour ago, kpinnc said:

I've seen similar with Vanguard V twins. Not the same, but similar. The head gaskets always are a weak spot. Some of the thinner sections tend to not seal well or break entirely, and combustion pressure bypasses into the crankcase. That can lead to pulse fuel pumps that overflow the carb bowl. Not to mention blowing oil into the breather, and eventual oil seal failures anywhere on the engine. 

 

 

What's a good way to check if those hydraulic lifters are bad? I have a Command that ticks like an old watch... 

You should be able to push down on and compress the lifter some, but it should not have lash after running.  If i get one in thats really rowdy ill put in about 4 oz of seafoam with the oil...run it full throttle a good 10 minutes, then override the governor to 4000 for a minute or two, drain the oil, fresh 10w30 and filter...and full throttle again.  If its got trash in the lifter this should clear it up, might take a few minutes on fresh oil.  If it doesn't clear up, its probably a bad lifter, ive taken them apart and cleaned them before..some come back.  You can use a strong magnet to pull them out the heads without pulling the heads if absolutely necessary.

[toma 12]

Hi..I am running 10w30. Al the valves press down a little when I press on the rocker. There is no lash. They all seam the same. 

[Pullstart 62,905]

44 minutes ago, toma said:

There is no lash.

Is that by the book?  Typically lash is there so when the metals expand at various rates, there is no unacceptable blow by anywhere.

[RED-Z06 2,221]

1 hour ago, Pullstart said:

Is that by the book?  Typically lash is there so when the metals expand at various rates, there is no unacceptable blow by anywhere.

Its a net lash valvetrain, the hydraulic lifters push up on the push rods and rockers, spec is 0.00/0.00 int/ex.

[RED-Z06 2,221]

2 hours ago, toma said:

Hi..I am running 10w30. Al the valves press down a little when I press on the rocker. There is no lash. They all seam the same. 

Do you have a compression or leakdown tester available to you?

[Pullstart 62,905]

9 minutes ago, RED-Z06 said:

Its a net lash valvetrain, the hydraulic lifters push up on the push rods and rockers, spec is 0.00/0.00 int/ex.

[toma 12]

I checked the compression and got 135 and 129. Then I turned the tractor over (with the valve covers off). I does indeed seem to be a stuck valve as the exhaust valve on the right side does not seem to be operating properly. Does this indicate a bad hydraulic lifter? If so how do I go about changing it? Do I have to take the head off again? Thanks..

[RED-Z06 2,221]

16 minutes ago, toma said:

I checked the compression and got 135 and 129. Then I turned the tractor over (with the valve covers off). I does indeed seem to be a stuck valve as the exhaust valve on the right side does not seem to be operating properly. Does this indicate a bad hydraulic lifter? If so how do I go about changing it? Do I have to take the head off again? Thanks..

Whats that valve doing vs the others? 

[toma 12]

It doesn't have the full motion as the others.

[toma 12]

I compared one head to the other the tuning the engine over. The plug on that side is dark and soot cover also.

[RED-Z06 2,221]

31 minutes ago, toma said:

It doesn't have the full motion as the others.

That sounds like a wiped out cam lobe.  This causes the running compression in that side to spike, it has to go somewhere when it doesn't all get out of the exhaust valve..so when the intake valve opens..it goes out the intake 

[toma 12]

Would that mean I need a new cam shaft?

[RED-Z06 2,221]

54 minutes ago, toma said:

Would that mean I need a new cam shaft?

If the cam is indeed hurt, then a cam and probably a new lifter set would be needed.  

[RED-Z06 2,221]

If your lifter was collapsed you would have a large amount of play in the rocker.

 

Check that the push rod isnt bent.

[toma 12]

There is no play in the rocker. The push rod is straight. Someone said to look for a sheared flywheel key. Could this cause the symptoms? I didn't hit anything that I noticed. 

[RED-Z06 2,221]

1 hour ago, toma said:

There is no play in the rocker. The push rod is straight. Someone said to look for a sheared flywheel key. Could this cause the symptoms? I didn't hit anything that I noticed. 

If you have a rocker visibly not moving as much as the others, thats thats your problem.  A sheared timing key causes loss of power, hard starting, misfiring...but it wont affect how the cam functions.

 

Can you take a video of the suspect rocker moving?  I can tajea video of one of my commands for comparison 

[toma 12]

Here are two videos of what is happening. The first video shows what happens when I up the throttle from a slow idle. The second one shows what is happening with the right side valves when I turn the tractor over. Any guesses or way to diagnose this? Thanks

[RED-Z06 2,221]

2 minutes ago, toma said:

Here are two videos of what is happening. The first video shows what happens when I up the throttle from a slow idle. The second one shows what is happening with the right side valves when I turn the tractor over. Any guesses or way to diagnose this? Thanks

You're certain that the push rod is on the lifter down below and not next to it?

[toma 12]

Im pretty sure it is..I looked down in and it appears ok. I could check again tomorrow. 

[RED-Z06 2,221]

Just now, toma said:

Im pretty sure it is..I looked down in and it appears ok. I could check again tomorrow. 

Alright.  If its on the lifter cup and not moving at all..the cam lobe is gone

[toma 12]

That sounds right...There is nobody I know competent in my area that I could trust to replace a cam. I might have to try it myself. 

[RED-Z06 2,221]

This is what a wiped command cam looks like,2nd lobe is the exhaust on cyl 2, and its perfectly round