Kohler magnum 18

V

valley ranch

Member
Joined
Jan 3, 2015
Threads
6
Messages
26
Greetings, Just came aboard.

I'm working on a Kohler Magnum 18 hp. Problem with petrol getting into the crankcase. I cleaned up the carb, didn't install a kit. There was no shut off solenoid in the carb, only the float valve. Changed the oil.

Question would you suspect the carburetor or the fuel pump? Have you run into this problem with the magnum? I see that the fuel pump is like the old mechanical pumps on car engines.

Thanks Richard
 
I

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,965
The needle valve isn't sealing against the seat allowing fuel to overflow the carb, and then run into the cylinder, past the rings, and into the oil. You will need to remove, clean and install a new kit to fix the issue. I have had to use valve grinding compound on the end of a Q tip sometimes to clean the seat, since the seat isn't replaceable on most of the kohler carbs.
 
reynoldston

reynoldston

Lawn Pro
Joined
May 23, 2011
Threads
92
Messages
5,705
ILENGINE said:
The needle valve isn't sealing against the seat allowing fuel to overflow the carb, and then run into the cylinder, past the rings, and into the oil. You will need to remove, clean and install a new kit to fix the issue. I have had to use valve grinding compound on the end of a Q tip sometimes to clean the seat, since the seat isn't replaceable on most of the kohler carbs.
Click to expand...

Doesn't the Kohler Magnum have a mechanical fuel pump? It can very well be a bad fuel pump as well.
 
I

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,965
Mech fuel pump failure could be a possibility but I have only seen I think 2 on 17 years, so they are not common, and need to check the carb for issues first, one because the fuel pump on these engines can be a pain to remove and install.
 
V

valley ranch

Member
Joined
Jan 3, 2015
Threads
6
Messages
26
Hi Guys, Thanks for coming by. I took the mechanical fuel pump apart. The diaphragm looked good and held vacuum ,you know when held to the tongue. I reinstalled it and ordered a carb kit.

I'm suprised kohler didn't arrange a better shut off for the magnum 18.

I had the carb out and cleaned it up earlier, guess I didn't pay close enough attention to the float valve and it's seat.

Again thanks for letting me know what you found and think. I'll let you know what the story is when I install the kit.
===================================================================================I'm making a lumber mill and plan to use this, the magnum 18, to drive the band blade. I've had this engine for several years, hope it does the job and holds up.


I have trouble finding my way back to the Kohler engine forum, it isn't listed under forums. If I do a SEARCH it takes me to some adds.

Richard
 
Last edited:
C

cashman

Well-Known Member
Joined
May 23, 2013
Threads
9
Messages
283
On the KT and Magnum twins, I've seen a couple of the fuel pumps where the body of the pump was cracked allowing fuel to enter the crankcase. The magnum engines were designed in the pre Walbro carb era and as far as I know, fuel shutoffs were never put on the K and Magnum engines.
 
V

valley ranch

Member
Joined
Jan 3, 2015
Threads
6
Messages
26
Got the carb kit #25 757 02-S. I'll rebuild the carburetor tomorrow, God willing. The float valve seat is replaceable and comes in the kit.

Richard
 
V

valley ranch

Member
Joined
Jan 3, 2015
Threads
6
Messages
26
Greetings, I installed the kit in the carb. Ran kinda good but not right, it wasn't until I came back in I remembered the govenor had been loosened and just tightened, I hadn't rotated the rod. I'll do that when next I get to the it, tomorrow if there's time.

Thanks for posting the manual, I have that. It's good though, slightly different than the one I have.

After I installed the kit, I read in the repair manual: For high altitude operation, and the # of another kit for that use. I would have ordered the other kit had I known, we are at 6800 ft here.

Also I've read primary adjustment for the carb both 1 1/2 AND 2 1/2 TURNS for the high speed jet which is correct?

Thanks again.

Richard
 
V

valley ranch

Member
Joined
Jan 3, 2015
Threads
6
Messages
26
Greetings, There's still a, little miss or stumble.

Richard

As for the carb adjustment: I've read two different for the kohler carburetor high speed jet: 1 1/2 turns and 2 1/2 turns out. I have it at 1 1/2 now.
 
You must log in or register to reply here.

Footer Links 1

Top