Exmark 22.5hp blowing white

[Tiger Small Engine]

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.

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.

 

[Douglas Lee]

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

 

[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

 

[slomo]

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.

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.

 

[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.

 

[Tiger Small Engine]

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.

I use the same copper spray on head gaskets and believe it really makes a difference in helping.

 

[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.

 

[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.

 

[lumpymags]

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.

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

 

[Peva]

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

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.