Kohler KT740-3011, running rich and rpm surging

bazar01

Member
Joined
May 27, 2018
Threads
3
Messages
37
I picked up a non-running old Troy-bilt Mustang 50inch sitting in a yard for almost 2 years.

Model: 17ARCACQ011
Date: 01/20/2015
SN: 1A195H10287

It wont run. I pulled the old carb. The throttle plate was stuck open.
I bought a new one from a local lawn mower store.
I got it running.

I have two problems.
1. I can smell gas from the exhaust. Sometimes i can see black smoke exhaust.
2. At full throttle, the rpm surges.

I have not done anything on the rich running condition. Any ideas?

What I have done on the rpm surging.
I adjusted the governor cross shaft at full throttle. Still surging.
I adjusted the valves to 0.005" both exhaust and intake. Some valves were very tight. Still surging after adjustment.
Any suggestions?

Thanks.
 

bazar01

Member
Joined
May 27, 2018
Threads
3
Messages
37
No ideas?

1. I plan to get a temperature gun and check exhaust temp on both cylinders.
2. It looks like the new fuel filter is not getting filled up completely. About halfway filled. Is this normal? Weak fuel pump?
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
248
Messages
6,432
i doubt the fuel pump is the problem if you're running too rich.
(Rich is more fuel than air, and lean is more air than fuel)
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
75
Messages
10,111
First verify you got the OEM 16 853 19-S carburetor as these are non adjustable other than the idle speed. Also make sure the choke is fully opening. IF you got a clone carburetor then it very well could be the problem.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
No ideas?

1. I plan to get a temperature gun and check exhaust temp on both cylinders.
2. It looks like the new fuel filter is not getting filled up completely. About halfway filled. Is this normal? Weak fuel pump?
Depending upon which filter you are using it may be normal
Some have the outlet 1/2 way down inside the the element so air gets trapped in the closed end if it is pointing up
When it worries people I fit the filter backwards ( makes no difference to operation ) and have the now outlet pointing up so air can escape .
 
Top