Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!

stlcardsfan88

Member
Joined
May 15, 2018
Threads
1
Messages
10
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
Okay, I went back in and cleaned off the head and the piston to the best of my abilities at the time. The piston cleaned up pretty well and I could not find any cracks. I also cleaned the head and again couldn't find anything out of the normal. I also looked over the cylinder wall and it looks in great condition. You can still see the lines from the initial factory honing on the cylinder wall. I have taken apart many briggs with worse condition cylinder walls that are still in great running condition. I also took a look at the breather valve cover on the crankcase and it looks pretty good. I have attached more pictures of each of the above mentioned points.

Tomorrow I am going to go rent a compression tester from the local auto parts store. Does anyone know what value I should be getting on this mower? If the compression checks out, any ideas?

Thanks everyone!

IMG_1713.jpgIMG_1712.jpgIMG_1711.jpgIMG_1710.jpgIMG_1709.jpg
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,643
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
Save your money.
A compression test will tell you absolutely nothing on these engines because of the decompression and if you defeat the decompression you will not be able to rotate the engine.
Normally I would have suspected the oil ring but generally when they are gone the engine smokes really badly.
At this point in time my tendency would be to pull the piston out & check the rings.
Also to check the bore for cracks.
In order to get oil blowing a few feet out of the breather you need a lot of crankcase pressure.
 

stlcardsfan88

Member
Joined
May 15, 2018
Threads
1
Messages
10
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
Save your money.
A compression test will tell you absolutely nothing on these engines because of the decompression and if you defeat the decompression you will not be able to rotate the engine.
Normally I would have suspected the oil ring but generally when they are gone the engine smokes really badly.
At this point in time my tendency would be to pull the piston out & check the rings.
Also to check the bore for cracks.
In order to get oil blowing a few feet out of the breather you need a lot of crankcase pressure.

Where is the automatic compression release even located on one of these engines. I thought they tended to only put those on larger (10hp+), guess not. Any thoughts on how I could jury-rig something to make a leak down tester? I would prefer not to have to buy any diagnostic tools. How difficult is splitting the case to remove the piston for checking the rings etc. I checked the bore pretty well from what is visible when the piston is down and couldn't find anything wrong with it.

Thanks,
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,643
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
Check out U-tube dozens of "how to make a cheap leak down tester " videos out there.
You can pump up the cylinder with a reasonably good tyre foot pump.
 

stlcardsfan88

Member
Joined
May 15, 2018
Threads
1
Messages
10
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
Check out U-tube dozens of "how to make a cheap leak down tester " videos out there.
You can pump up the cylinder with a reasonably good tyre foot pump.

Okay. I built a leak down tester. How long should it hold 100 psi? When I take the reading from the second gauge do I wait some amount of time to take it?
 

stlcardsfan88

Member
Joined
May 15, 2018
Threads
1
Messages
10
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
Check out U-tube dozens of "how to make a cheap leak down tester " videos out there.
You can pump up the cylinder with a reasonably good tyre foot pump.

Okay. So I built a leak down tester and used it. I had the regulator at 100psi and was reading about ~94 psi on the second gauge. From what I can tell these are good results? Can anyone confirm? If they are good, any other ideas on what to test besides tearing the whole thing down and checking all specs?
 

Sigro

Forum Newbie
Joined
Jul 16, 2023
Threads
0
Messages
1
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
I know this is an old post, but I’m at the same spot with my mower
I replaced the head gasket and cleaned the CC vent spring and cap and opened the oil drain hole
I’m still having oil overflow
I guess pulling the piston and replacing the rings is next,
just wondering if the OP ever solved his problem or identified the cause
thanks
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
74
Messages
10,100
  • / Kohler XT 675 Spitting Oil Out Crankcase Breather - HELP!
1689531306076.png.
 
Top