Kohler KT725 22HP Exhaust pipe glowing red

rightnitro

Forum Newbie
Joined
Jan 24, 2021
Threads
2
Messages
5
Hi guys, I have a 2015 cub cadet with a 22hp KT725. I just fixed my governor and the thing idles great now, however it's running rich as a son of a bitch (exhaust has that rich disgusting smell) and the left exhaust pipe is glowing red if the throttle goes above half. What should I check for this?
 

rightnitro

Forum Newbie
Joined
Jan 24, 2021
Threads
2
Messages
5
Just took the valve cover off. The exhaust valve looks scorched. The clearance was at .010" (spec is .004-.006). The center stud had backed out a bit. I tightened that up and adjusted the clearance to .005". Is this head toast?
 

Attachments

  • head 2.jpg
    head 2.jpg
    620.6 KB · Views: 14
  • head.jpg
    head.jpg
    623 KB · Views: 13

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,855
Definitely some oil coking around that valve, but also hints of some oil additive that doesn't like air cooled engines like STP treatment. It maybe fine but I would be either doing a leak down test to make sure the valve is sealing or pull the head even just to clean it up for a better look
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Heads can be fixed it is just a case of what is the most expensive, repair or replace.
That exhaust has been running way too hot and by the looks of it leaking up the valve guide.
If the head gets too hot it can destroy the heat treatment, most small heads are a T6 temper and if overheated can get too soft.
But start by pulling the head & the exhaust valve
 

rightnitro

Forum Newbie
Joined
Jan 24, 2021
Threads
2
Messages
5
Looks like a new head assy is $140. I'll give this a shot since it's just a quick swap.
 
Top