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Exmark 22.5hp blowing white

#1

L

lumpymags

Severe amount of white smoke problem is this winter I rebuilt it split sump everything looked great new head gaskets and the valves were lapped to remove little pitting today I put the engine back on and it is still smoking like last year I have checked the read valve seems to be working as it should I am at a loss I unscrewed the oil dip stick and cranked it over and oil shot out the tube so I pulled the flywheel and the breather I do t see a clog anywhere I am so confused on this any info would be great


#2

R

Rivets

To me it’s a classic example of a blown head gasket. Since you say you had the heads off I suspect 1 of 3 causes. Head and block surfaces not cleaned properly or head warped. Reused the head gaskets, that’s a NO, NO. Head gaskets not torqued in proper sequence or torque.


#3

L

lumpymags

Rivets said:
To me it’s a classic example of a blown head gasket. Since you say you had the heads off I suspect 1 of 3 causes. Head and block surfaces not cleaned properly or head warped. Reused the head gaskets, that’s a NO, NO. Head gaskets not torqued in proper sequence or torque.
Click to expand...
All were done to spec I always use scotch Brite pads remove everything and brand new gaskets I never reuse and I torqued to the exmark spec I just ran it for 40 minutes sounds good but smoke it would clear up the hit again and I burnt from full to fill level I am going to do another leak dow tonight this machine has been keeping me up at nights I don't like when I can't figure things out


#4

S

slomo

When you remove a head, you must lap the head and block area where the head sits. It's all in the prep. You don't clean the area and toss on a new gasket.

Every head I've pulled from 2hp to say 22hp, all were warped. 220, 400 and 800 grit on the garage door window. Let the paper do the work. No need to push hard while lapping. You will quickly see how warped it is.

Last a triple bolt torque regime should be followed. And after running once or twice retorque the bolts a few times. Only takes a minute.


#5

L

lumpymags

slomo said:
When you remove a head, you must lap the head and block area where the head sits. It's all in the prep. You don't clean the area and toss on a new gasket.

Every head I've pulled from 2hp to say 22hp, all were warped. 220, 400 and 800 grit on the garage door window. Let the paper do the work. No need to push hard while lapping. You will quickly see how warped it is.

Last a triple bolt torque regime should be followed. And after running once or twice retorque the bolts a few times. Only takes a minute.
Click to expand...


#6

S

slomo

lumpymags said:
I always use scotch Brite pads remove everything
Click to expand...
You know those are abrasive right? You are cleaning aluminum parts. Scrapping or sanding is your last resort. Lacquer thinner, glass cleaner and such are good to start off with. Razor blades and such, huge no-no.


#7

L

lumpymags

I do the 3 phase torque on heads as you say quick and why not I do not do sanding I guess I should try that from now on I do know the guys at the machine shop very well never ranyo this just did a compression test and I am at 112 and 110 but my tester i have little faith in I have to grab my friends spendy one in the morning and recheck


#8

L

lumpymags

slomo said:
You know those are abrasive right? You are cleaning aluminum parts. Scrapping or sanding is your last resort. Lacquer thinner, glass cleaner and such are good to start off with. Razor blades and such, huge no-no.
Click to expand...
This would be the first trouble I have had using them I use the thinner and move it back and forth with little pressure until clean


#9

L

lumpymags

Leak down test 6 to 7 percent on both cylinders and that me trying to hold and plug in at 100 psi


#10

L

lumpymags

After some talk with my friend i think I left out a big part when the dipstick is removed it will shoot oil out for a distance so I do believe and agree with my friend that the rings are somewhat compromised I will be removing and disassembling again and will inform the forum


#11

Tiger Small Engine

Tiger Small Engine

slomo said:
When you remove a head, you must lap the head and block area where the head sits. It's all in the prep. You don't clean the area and toss on a new gasket.

Every head I've pulled from 2hp to say 22hp, all were warped. 220, 400 and 800 grit on the garage door window. Let the paper do the work. No need to push hard while lapping. You will quickly see how warped it is.

Last a triple bolt torque regime should be followed. And after running once or twice retorque the bolts a few times. Only takes a minute.
Click to expand...
Slomo-
I usually run a .002” feeler gauge under cylinder head to check for any warping with head on glass. How do you determine straightness?

7% leak down is very low with anything below 20% considered acceptable. If engine had higher hours on it and you opened it up, replacing the rings is the way to go. Also polishing the piston, and honing the cylinder and lapping the valves.


#12

D

Douglas Lee

Ok,
Keep us posted . . .
The answer will be interesting!
Thanks,
Doug Lee
*


#13

L

lumpymags

I wanted to update everyone on this problem I took the engine out last night and tore it down today this mower is a 2017 model with 218 hours once I pulled the pistons cylinders 2 I think the lower one anyways the compression ring end gaps were maybe an 1/8th of an inch apart so ordered complete rebuild for 200 bucks did my honing and lapping and will let everyone know how it turns out had to be a factor issue as this is it's first complete tear down


#14

S

slomo

Tiger Small Engine said:
Slomo-
I usually run a .002” feeler gauge under cylinder head to check for any warping with head on glass. How do you determine straightness?

7% leak down is very low with anything below 20% considered acceptable. If engine had higher hours on it and you opened it up, replacing the rings is the way to go. Also polishing the piston, and honing the cylinder and lapping the valves.
Click to expand...
I don't use feelers. Just lap the head and the block area with a small sheet of plate glass. The block area doesn't come out perfect but way better than what it was. Just lap it till you see the material flatten out best as you can. Small figure 8 swipes. Let the sanding paper do ALL THE WORK. Rotate the sanding material around periodically. Use your hand with open fingers to limit compression weight/pressure against the head. If you want you can use a good straight edge and a flash light. A laser pointer works too.

I use hi tack spray adhesive from Permatex as well on both sides of a NEW GASKET.

Suggested Applications

Cylinder head gaskets, exhaust manifold gaskets, and other high temperature applications.

1741991649712.png


#15

S

slomo

With good prep, lapped parts, new head gasket and hi tack spray, I've never had an Intek Briggs toss the head gasket again. Normally, knock on wood, a permanent repair. Again it's all in the prep.


#16

Tiger Small Engine

Tiger Small Engine

slomo said:
With good prep, lapped parts, new head gasket and hi tack spray, I've never had an Intek Briggs toss the head gasket again. Normally, knock on wood, a permanent repair. Again it's all in the prep.
Click to expand...
I use the same copper spray on head gaskets and believe it really makes a difference in helping.


#17

R

Rivets

Have more questions than answers. Before ordering any parts please help us.
1. Please supply us with all engine numbers.
2. Did you measure the cylinders with a telescoping and vernier? Two measurements at top, middle and bottom, 90 degrees apart. This will tell us if you need to go with oversized rings and piston.
3. Measure ring end gap. Most rings will have a gap of .025”-.045” depending on brand and engine size. Saying the end gap is near .25” tells me you have a problem that won’t be fixed cheaply.


#18

VRR.DYNDNS>BIZ

VRR.DYNDNS>BIZ

Stop! check the breather. Two things pressurize the crank case. Rings and breather check valve function. Of course head gasket is also a possibility, but lets go the easy route - check the breather.


#19

L

lumpymags

VRR.DYNDNS>BIZ said:
Stop! check the breather. Two things pressurize the crank case. Rings and breather check valve function. Of course head gasket is also a possibility, but lets go the easy route - check the breather.
Click to expand...
Breather is functioning good and very clean after when I pull the pistons out the rings in the lower cylinder were not spaced 120 degrees there ring end gaps were about an 1/8inch apart pretty sure it is the problem but having it tore down I figured just rebuild with new


#20

P

Peva

lumpymags said:
Severe amount of white smoke problem is this winter I rebuilt it split sump everything looked great new head gaskets and the valves were lapped to remove little pitting today I put the engine back on and it is still smoking like last year I have checked the read valve seems to be working as it should I am at a loss I unscrewed the oil dip stick and cranked it over and oil shot out the tube so I pulled the flywheel and the breather I do t see a clog anywhere I am so confused on this any info would be great
Click to expand...
A personal request: When you post, please use sentence punctuation and capitalization. Not readily knowing where sentences end and begin makes it more tedious to read and understand, and increases likelihood of confusion about what is being explained.

Thanks.


#21

L

lumpymags

VRR.DYNDNS>BIZ said:
Stop! check the breather. Two things pressurize the crank case. Rings and breather check valve function. Of course head gasket is also a possibility, but lets go the easy route - check the breather.
Click to expand...
Breather is functioning good and very clean after when I pull the pistons out the rings in the lower cylinder were not spaced 120 degrees there ring end gaps were about an 1/8inch apart pretty sure
Peva said:
A personal request: When you post, please use sentence punctuation and capitalization. Not readily knowing where sentences end and begin makes it more tedious to read and understand, and increases likelihood of confusion about what is being explained.

Thanks.
Click to expand...
Well hell I thought it was lawn mower forum not English class


#22

S

slomo

lumpymags said:
Well hell I thought it was lawn mower forum not English class
Click to expand...
(y)


#23

P

Peva

lumpymags said:
Breather is functioning good and very clean after when I pull the pistons out the rings in the lower cylinder were not spaced 120 degrees there ring end gaps were about an 1/8inch apart pretty sure

Well hell I thought it was lawn mower forum not English class
Click to expand...
soifitypelikethisthatwouldbeokbecausethis isn'tanenglishclassit'salawnmowerforum?

Seriously - it makes it easier for the reader to understand what you're saying. A little extra effort on your part so 10 or 15 people don't have to spend the same extra effort each to read it. Also, there are situations where not knowing where one sentence stops and another starts totally affects what the information is. Basically show a little respect to people who are here to help you. This might offend you, and that's OK too. 🫡 😁


#24

S

slomo

Not all of us are English scholars. Let's relax on those that are not as fortunate.


#25

Tiger Small Engine

Tiger Small Engine

slomo said:
Not all of us are English scholars. Let's relax on those that are not as fortunate.
Click to expand...


I see poor spelling and punctuation all the time on line. The way I look at is, I am glad I got my education.


#26

R

Rivets

I’ll take the bad grammar anytime over the people who fail to provide us with the info we need to help them. They then get mad when we don’t provide the answers they want to hear. Thegrammarpolice are locatedontheSocialTruth forum


#27

S

S.A.E.

Rivets said:
I’ll take the bad grammar anytime over the people who fail to provide us with the info we need to help them. They then get mad when we don’t provide the answers they want to hear. Thegrammarpolice are locatedontheSocialTruth forum
Click to expand...
hey, rivets.... i got this greasy, filthy mower from my moms, cousin's, sister's neighbor. What do you think is wrong with it? She no fire!


#28

R

Rivets

Does your mom’s cousin’s, sister’s neighbor smoke, if not then the cause is good upbringing.


#29

P

Peva

Rivets said:
Does your mom’s cousin’s, sister’s neighbor smoke, if not then the cause is good upbringing.
Click to expand...
Someone asked me one time if I smoked after sex. I told them "I don't know - I never looked".


#30

S

slomo

Peva said:
Someone asked me one time if I smoked after sex. I told them "I don't know - I never looked".
Click to expand...
Stolen from an Austin Powers movie. Classic!!!


#31

B

bentrim

OP It would help if you posted the engine make and model all manufactuers made an engine with 22 horsepower.
If we are told this information someone who is knowledgable on certain makes and models may know of a the problem area of the engine, and be able to give you better advise on the issue.
Kohler had ring and head gasket issues.
Kawasaki changed the breather
These things are just some engines that had issues, note I said no specific models.
Note a breather issue will allow the crankcase to become pressueized and push oil thru the line to the carburetor, the engine ingests the oil and---smoke.
The crankcase should be under a slight vacuum.

Please note -- Large shaky fingers sometimes hit the wrong or more than one key. Sorry for any misspellings I never excelled in spelling either.


#32

F

Forest#2

As Rivets indicates in post #17.

Post up the engine model, type, code (especially the code)

The rings on some had a parts number change per the code.


#33

B

borisdmower

When mine went it was the oil scrapper ring, belching white smoke everywhere, couldn’t see the front of the mower. Crazy thing was, the bore and compression rings were spot on.


#34

G

Gord Baker

lumpymags said:
Severe amount of white smoke problem is this winter I rebuilt it split sump everything looked great new head gaskets and the valves were lapped to remove little pitting today I put the engine back on and it is still smoking like last year I have checked the read valve seems to be working as it should I am at a loss I unscrewed the oil dip stick and cranked it over and oil shot out the tube so I pulled the flywheel and the breather I do t see a clog anywhere I am so confused on this any info would be great
Click to expand...
I am not familiar with this engine. Is it Liquid cooled? If not, perhaps you have some water in the fuel. Do a compression check or Pressure test the Crankcase.


#35

G

Gord Baker

lumpymags said:
After some talk with my friend i think I left out a big part when the dipstick is removed it will shoot oil out for a distance so I do believe and agree with my friend that the rings are somewhat compromised I will be removing and disassembling again and will inform the forum
Click to expand...
Check for CrankCase Vent FIRST.


#36

kbowley

kbowley

Peva said:
Someone asked me one time if I smoked after sex. I told them "I don't know - I never looked".
Click to expand...
:LOL::ROFLMAO::D:eek:🔥


#37

kbowley

kbowley

With a Briggs engine producing white smoke, my initial focus is on the head gasket(s). With that in mind, and based on your work, my next action is to detach the breather tube from the air cleaner and see if it expels oil. Try switching the valve covers to check the breather tube on the other cylinder. To summarize, the crankcase pressure is too high and is finding a path of least resistance for escape. The cause of the pressure is the puzzle in your instance. The leak-down test shows no issues with rings, warping, or cylinders. It’s possible that the oil pump bypass valve is obstructed (pump replaced) or that oil is leaking through the valve guides. My thought process leads me to a defective breather valve, oil pressure bypass valve, or valve guide.


#38

kbowley

kbowley

Peva said:
A personal request: When you post, please use sentence punctuation and capitalization. Not readily knowing where sentences end and begin makes it more tedious to read and understand, and increases likelihood of confusion about what is being explained.

Thanks.
Click to expand...
Just wanted to check in and see if the grammar in my casual response in the previous post is up to your standards :ROFLMAO: .


#39

C

Combat_Pyro

I’m seeing a lot of questions about the head gaskets, but no one mentioning the fact that it blew smoke before and after the heads were done. To me that sounds like a PCV valve might be bad. I don’t know if that engine has one or not but if it does it’s usually pretty simple and cheap to change. I’d check that out before anything else.


#40

K

kjonxx

over filled with oil will also cause this, maybe leaking carb N+S


#41

R

Rocky J

kjonxx said:
over filled with oil will also cause this, maybe leaking carb N+S
Click to expand...
I have had both of these issues you mention cause clouds of white smoke. One was a dip stick from another engine tricked the user to overfill , if it fits it ships . The other was carb not shutting off the fuel and draining into the engine oil, common on models with gas tank higher then engine .


#42

R

RevB

lumpymags said:
Severe amount of white smoke problem is this winter I rebuilt it split sump everything looked great new head gaskets and the valves were lapped to remove little pitting today I put the engine back on and it is still smoking like last year I have checked the read valve seems to be working as it should I am at a loss I unscrewed the oil dip stick and cranked it over and oil shot out the tube so I pulled the flywheel and the breather I do t see a clog anywhere I am so confused on this any info would be great
Click to expand...
Lapping does not remove pits. All you did was polish the pits.
What were the condition of the valve guides. Are there oil seals on the guides.


#43

R

RevB

lumpymags said:
Leak down test 6 to 7 percent on both cylinders and that me trying to hold and plug in at 100 psi
Click to expand...

lumpymags said:
I wanted to update everyone on this problem I took the engine out last night and tore it down today this mower is a 2017 model with 218 hours once I pulled the pistons cylinders 2 I think the lower one anyways the compression ring end gaps were maybe an 1/8th of an inch apart so ordered complete rebuild for 200 bucks did my honing and lapping and will let everyone know how it turns out had to be a factor issue as this is it's first complete tear down
Click to expand...
A complete "rebuild" as in next oversize piston? Cylinder machined to fit? At 218 hours I'd seriously think about rebuilding something that only lasted that long.


#44

R

RevB

Rivets said:
Have more questions than answers. Before ordering any parts please help us.
1. Please supply us with all engine numbers.
2. Did you measure the cylinders with a telescoping and vernier? Two measurements at top, middle and bottom, 90 degrees apart. This will tell us if you need to go with oversized rings and piston.
3. Measure ring end gap. Most rings will have a gap of .025”-.045” depending on brand and engine size. Saying the end gap is near .25” tells me you have a problem that won’t be fixed cheaply.
Click to expand...
Finally. 🤫


#45

G

Gord Baker

Don't overthink this. Run it for 30 minutes and note any changes. Clear Crankcase vent tube. Oil at correct level?
Ring Dia appears correct. 0.004" per inch of bore is nominal. Did you stagger the ring ends 120°? They must NOT be aligned. Re torque head bolts when Cold. Not worth expensive rebuilding IMHO


#46

S

S.A.E.

RevB said:
A complete "rebuild" as in next oversize piston? Cylinder machined to fit? At 218 hours I'd seriously think about rebuilding something that only lasted that long.
Click to expand...
be sure to flush ALL grinding compounds and trash from all pathways.


#47

kbowley

kbowley

Respectfully, none of the above are related to your issue. Your cylinder, rings, and valves are great, as your leakdown test confirms. The issue is: crankcase breather, oil pressure, or valve guide(s). Now, could you PLEASE provide us with your engine information, please! Hell, we don't even know the manufacturer of the engine, so provide it, or I am out.


#48

L

lumpymags

To finish off this thread a lot of great info you all gave me thank you. I think I put a period there. It was the rings and I figured just do the rebuild machine shop was nuts on head surfacing so I did do the 80 grit 150 to 600 grit paper on block and heads first start no smoke and purrs like a kitten


#49

G

Gord Baker

lumpymags said:
To finish off this thread a lot of great info you all gave me thank you. I think I put a period there. It was the rings and I figured just do the rebuild machine shop was nuts on head surfacing so I did do the 80 grit 150 to 600 grit paper on block and heads first start no smoke and purrs like a kitten
Click to expand...
Well done sir.


#50

kbowley

kbowley

I find that very strange, as defective rings or a warped head would show up in the leak-down test. However, the oil rings could have been installed upside down and allowed oil to pass by. Also, you never posted your engine manufacturer or model number. Weird thread.
lumpymags said:
To finish off this thread a lot of great info you all gave me thank you. I think I put a period there. It was the rings and I figured just do the rebuild machine shop was nuts on head surfacing so I did do the 80 grit 150 to 600 grit paper on block and heads first start no smoke and purrs like a kitten
Click to expand...


#51

I

Idaho Dave

Just a do-it-yourselfer, years ago I rebuilt a 4HP Kohler on my wood splitter, same problem, cause: put the compression ring on backwards.


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