Kohler CV490S no power, runs hot

ptfarmer

Forum Newbie
Joined
Feb 17, 2019
Threads
1
Messages
3
Hello, I have Sears Craftsman riding mower with a Kohler CV490S (17hp, 1 cylinder), and I having a problem with the engine. When set at operating speed while everything is in neutral the engine isn't running fast as it should (sounds like it running under a real heavy load), and the exhaust/muffler glows orange. I checked the compression, replaced the spark plug, fuel filter, air filter, oil/filter, cleaned the carburetor as best as I could, it's getting good fuel flow to the carb, and tested the electric fuel shut off solenoid (works as it should). If I try to choke it, or idle it, it will die out (it is also now hard to start when it's either cold, or hot). It ran fine yesterday for 3 hours, but went to run it this morning, and it just don't want to run right at all. Anyone have any ideas, I'm at a loss with it :confused2: !!
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
What type of carburettor does your engine have.
Should be cast into the side. Nikki or Walbro ?
If it was a nikki that has the white plastic bit between the bowl & the carb body, there is a small jet that is easy to loose if you don't know it's there.
Come to think of it, not all that hard to loose it even if you do know it is there.

A red hot exhaust is usually either a retarded spark or too big a main jet , or both.
Low power , labouring & running slow are also signs of retarded timing.
So whip off the blower cover and the flywheel retaining bolt ( might be a nut ) .
Under the washer should be a slot with the timing key which is 1/2 in the flywheel & 1/2 in the shaft.
They must come together to make a perfect square.
Hopefully yours will not be in line so a new key will make it an easy repair.
Your coil could have 1 2 or 3 small ( not the spark plug ) wires.
Let us know how many , posting a pickky would be good.
Some Kohlers had an electronic ignition and these have several wires to control the spark timing.
These unit are known to fail .
 

ptfarmer

Forum Newbie
Joined
Feb 17, 2019
Threads
1
Messages
3
It has the Walbro carburetor, and after making sure the carb was clean I'm thinking it's a timing/ignition issue issue. I also tried it with the rubber tip removed from the shutoff solenoid, and it still ran the same. I know the solenoid works because I unplugged it while it was running, and it killed the engine. The coil only has one wire running to it, so I plan to remove the flywheel bolt to see if the flywheel has moved.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Please try running it with the kill wire unplugged as well.
If one of the safety wire switches is going bad it will cut the spark.
If it is just doing this a little bit you get unburned charge passing through the engine then burning in the exhaust .
Usually you can hear it missing but some times the miss is just one cycle every 4 or 5 so it is hard to hear.
I did not mention this before because you did not mention a miss.
 

ptfarmer

Forum Newbie
Joined
Feb 17, 2019
Threads
1
Messages
3
There is no miss fire I can hear, I haven't had a chance to work on it today, but I will see if unplugging the kill wire does anything.
 

Fish

Lawn Pro
Joined
Aug 2, 2013
Threads
11
Messages
5,123
Definitely check the flywheel key!
 
Top