LX277, black smoke.

wfrpalm

Member
Joined
Apr 22, 2012
Threads
9
Messages
31
I have a LX277 with about 300 Hrs, lately when I start it after it is warm or when I engage the PTO it blows a puff of black smoke. I changed the plugs and they were very sooty. Any ideas?
 

mechanic mark

Lawn Pro
Joined
Jul 15, 2013
Threads
175
Messages
7,381
Inspect air filter for replacement, with engine cold check valves for adjustment.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
That is one sign of a leaking head gasket
When you finish mowing , turn the engine off, count to 10 then remove the dip stick
If wispy whitish smoke rises from it that is a second sign of a leaking gasket .
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,677
I have a LX277 with about 300 Hrs, lately when I start it after it is warm or when I engage the PTO it blows a puff of black smoke. I changed the plugs and they were very sooty. Any ideas?
Rich runner. Lack of air or excessive fuel.

1.Agree on looking at air filter and valves.
2.Carb needle needs pressure testing.
3.Pull the oil dipstick and smell for fuel.
4.Pull engine shroud and clean cooling fins and block - YEARLY. This is a must do maintenance item in yours and ALL other engine manuals.
5.Carb float level needs inspection.

Is this a one ignition coil firing 2 plugs engine? If so might have a weak coil or coil ground issue.
 

wfrpalm

Member
Joined
Apr 22, 2012
Threads
9
Messages
31
Thanks for the suggestions, I will check things out.
 

wfrpalm

Member
Joined
Apr 22, 2012
Threads
9
Messages
31
I just checked the air filter and is very dirty, the pre filter was covered with caked on debris.
 

wfrpalm

Member
Joined
Apr 22, 2012
Threads
9
Messages
31
Ok, I replaced the air filter a few weeks ago but never started the LX until today. When I started it up it chugged 4 or 5 times and made a puff of black smoke at each chug and when I engaged the PTO it blew a puff of black smoke but ran good otherwise. I shut it down after 5 or 6 minutes to gas up and it started up with no smoke and when I engaged the deck it not smoke and ran great.
 
Top