Bad Boy 6K ZT Elite - Kohler 7K series 747 blowing oil - running raggedly

[JBP]

Problem: Bad Boy 6000 ZT Elite - Kohler 7000 series 747 blowing oil out of dipstick and running raggedly.

Operator (not me) heard a 'clunk' or 'thud' or some such noise when cutting. But the engine did not start running roughly at that point (used for another hour at least).

After sitting for several hours midday, went out to start cutting again. Engine did not want to crank over, had to jump start it using my truck (mower battery is not old). When it did start is when I observed the problem of oil blowing out and engine running ragged at higher rpm.

one suspicion I have is that the engine overheated and something gave way, because its 90-some degrees and the damn engine 'grill' that covers the flywheel was just about completely covered with grass/debris.

Mower now blows oil like mad out of the dipstick (see image). The 'ray of sunlight' pointing to the oil hole is oil spraying out.

Engine runs smooth at idle, but a noticeable bit raggedy and weak when revved up.

After reading several other threads here I will be checking the blow-by port (supposedly comes out into the air filter compartment on the right side?).

The oil did not smell 'gassy'.

 

[slomo]

one suspicion I have is that the engine overheated and something gave way, because its 90-some degrees and the damn engine 'grill' that covers the flywheel was just about completely covered with grass/debris.

Stop everything and clean the block and cooling fins like a new engine. Pull the top engine cover and scrub scrub. This is a yearly maintenance item in yours, mine and everyone else's engine manuals. More often if you bag or scalp in the spring. Leaf blower, shop air and an old paint brush. Some 409 degreaser down to bare aluminum.

Take pictures of the cooling fins prior to cleaning and post them back up here.

 

[bertsmobile1]

Crankcase pressure will cause a strong blow out of the dip stick tube even on a good engine
That much could be nothing more than an overfilled crankcase which causes a lot more oil to be splashed around
And then again your could win this months lottery
Without a doubt you have a blown head gasket or two
If hydro-locking caused it then you might have a broken piston ring or two as well
And if a seizure occurred then perhaps a hole in a piston or broken rod

SO
1) remove both plugs , shove a stick down the plug holes rotate the engine by hand 2 revolutions each side and feel for both pistons going up & down, the same amount and finishing the same distance from the spark plug
If one does not move you have a broken rod or piston
If they stop at different distances from the spark plug then you have a bent con rod

Either of these are going to be big = expensive repairs that will take at least a week if not longer .
As that is a commercial mower your best bet is a replacement engine which will only have your team sitting on their butts under a tree for a couple of days .

2) If they feel OK then whip the rocker covers off and check that both rockers are moving up & down the same amount inlet & exhaust both sides
Then pull out the pushrods , check for straitness
Next pull the heads off for a visual inspection of the pistons & bores
All of this can be done engine in mower tonight
If all is good then go out tomorrow & buy the new gaskets & button it back up
If all is not good then go to Small Engine Supplies , Small Engine Warehouse, Surplus Centre and get a surplus engine .
It should get to you in a couple of days so tomorrow night you can pull the engine out

DO NOT CRANK THE ENGINE USING THE STARTER MOTOR
If one of the rods has gone then you will damage the bore beyond repair
If it has dropped a pushrod into the crank case you can end up wrecking the cam

Get back to us with what you find plus mower make model & numbers + engine make model & numbers
That looks like a Kohler or Loncin from the small amount visible in your photo

While you are waiting for parts do as Slowmo suggest and give the block a good cleaning

 

[JBP]

Well I'm an idiot

again.

One of the spade connectors for the kill-switch for the right drive-arm had come loose; however, instead of falling completely away, it was held against the mating half by electrical tape. Just enough to be intermittent and hard to figure out.

In the meantime while trying to figure out what was wrong I did remove the shroud and clean off the crankcase inside. It actually was clear of gunk and only had small bits of dry grass etc here and there. Pulled and blew all of that out.

Fixed the wire, and off to the races; cut for an hour and some, ran like a top. Jinx there I guess.

Thanks for checking in on this edition of; what the heck has JBP overlooked this time.