crankcase high pressure

Have you checked the oil fill port cap for being fully sealed? I lost the O-ring on my Kohler once, and it decided to blow oil everywhere. It has been a while, and I really don't remember the exact details, but the O-ring either got damaged or fell out when I was checking the level 'out there' instead of in the garage. It made a surprising mess.
tom
ADDED: If you actually have high pressure in the crankcase, either you have an air leak or the rings are allowing too much blowby. The former is the pumping action pulling air through a leak, and pushing(trying anyway) to push it back out as the piston comes back down. Blowby is the engine itself providing excess air into the crankcase, where it goes through the same process.
You could get a plastic bag or grocery plastic bag, rubber band it to the dipstick/fill port, and run the engine. If you are pumping air, the bag should blow up even though it is sealed, indicating air supply from elsewhere...
tom
 
If you're saying it's blowing out of the oil fill while running with the cap off, that's totally normal. To work correctly, the system needs to be sealed.
 
sparkyjoe said:
I have a 1986 gravely with a rebuilt kohler kt17. new rods, new pistons and rings, new valve guides and new valves. heads totally redone.
Click to expand...
I notice that you didn't mention head gaskets. Since heads are "totally redone", I'd assume that includes head gaskets. If not, I'd replace them. Make sure the breather and reed is installed correctly, and none of the breather passages are clogged.
 
Did the head/s get lapped and a proper valve job done?

De-carbon the cylinder/s per your engine manual?

Valves move as normal not hanging open causing more pressure?
 
Gentleman is 81 I saw (y). Did the rings get installed upside down???? Something was missed here.

Cam timing waaay off??

OP said it only runs on full choke.
 
Are all those "new" parts OEM Kroller?

If you pull the oil dipstick while running, should be plenty to vent the crankcase pressure on a fresh engine. Shouldn't be pumping out oil and blowing crank seals.......
 
Rivets said:
About 10 years ago I had this same problem and found that the oil return ports into the crankcase, behind the seals, were plugged. This would allow oil pressure to build up, blowing out the seal. Luckily I was doing this repair at home so I didn’t have to charge shop rate for 10-12 hours or labor to find and solve this problem. Here is a manual for your engine. https://mymowerparts.com/pdf/Kohler...hler-Service-Repair-Manual-KT17-KT19-KT21.pdf
Click to expand...
Like you say, blocked oil return at the main bearing or the sleeve bearing was installed without the oil hole in the bearing lined up with the oil hole in the block.
 
yes, bearing oil holes lined up perfect. ive rebuilt several of these motors. never had one problem at all. Rebuilt a to z with manual
 
slomo said:
Are all those "new" parts OEM Kroller?

If you pull the oil dipstick while running, should be plenty to vent the crankcase pressure on a fresh engine. Shouldn't be pumping out oil and blowing crank seals.......
Click to expand...
Rings installed proper direction and clocked
 
You must log in or register to reply here.
Back
Top