Help- lawn mower making knocking sound and trimmer smoking white

alpha1976

Forum Newbie
Joined
Apr 13, 2022
Threads
1
Messages
6
  • / Help- lawn mower making knocking sound and trimmer smoking white
Hi all,

It's my first post and I need some help. This is a Poulan lawnmower with GCV160 Honda engine. It was working perfectly last summer when I ran it until all the gas in tank was consumed. I always change engine oil at the beginning and did that yesterday as well as sharpen the mower blade. Engine ran on first pull but heard some knocking sound like metal against metal. When I take the blade off - engine runs smoothly. However, I have looked everywhere and blade is not touching anything. What could be wrong? Or is it still engine related?

Thanks a lot.
Madhu
 
Last edited by a moderator:

sgkent

Lawn Addict
Joined
Sep 27, 2017
Threads
30
Messages
1,679
  • / Help- lawn mower making knocking sound and trimmer smoking white
new fuel and new oil of the correct viscosity before it was run this year? Check the oil for correct height? Any debris in the oil? All belts Ok, no rat or mouse damage?
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,768
  • / Help- lawn mower making knocking sound and trimmer smoking white
Make sure the blade adapter, blade and engine mounting bolts are tight.
 

alpha1976

Forum Newbie
Joined
Apr 13, 2022
Threads
1
Messages
6
  • / Help- lawn mower making knocking sound and trimmer smoking white
Thanks everyone. After reading your replies and went back thinking it had to be something really silly that i did. And that turned out to be the case. After putting in a new spark plug, new gas and everything it turned out to be blade!! It wasn't tight enough. All good now. Thanks again. Now i have white smoke coming from my black max gas trimmer - not sure what that is all about. I read online that this means too little oil but that is not possible as i added 10ml in 500ml of gas!
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,768
  • / Help- lawn mower making knocking sound and trimmer smoking white
White smoke normally means water in the fuel. If the white smoke clears up after a couple of minutes, nothing to worry about. If it doesn’t clear up, dump the fuel in a glass jar, cover and shake vigorously. If it gets cloudy, or you see it separating at the bottom after sitting for 5 minutes, dump your gas and start over with fresh.
 

OldDiyer

Well-Known Member
Joined
Jun 7, 2021
Threads
17
Messages
130
  • / Help- lawn mower making knocking sound and trimmer smoking white
new fuel and new oil of the correct viscosity before it was run this year? Check the oil for correct height? Any debris in the oil? All belts Ok, no rat or mouse damage?
Guess you missed the fact that it ran fine without the blade being on the machine. Kind of takes the engine out of the picture all together. Glad that the OP went for the blade first because that is where most would have gone.
 

alpha1976

Forum Newbie
Joined
Apr 13, 2022
Threads
1
Messages
6
  • / Help- lawn mower making knocking sound and trimmer smoking white
White smoke normally means water in the fuel. If the white smoke clears up after a couple of minutes, nothing to worry about. If it doesn’t clear up, dump the fuel in a glass jar, cover and shake vigorously. If it gets cloudy, or you see it separating at the bottom after sitting for 5 minutes, dump your gas and start over with fresh.
Yes that's the plan now. I am not sure from where the water will come though. For trimmer, I used fresh ethanol free gas mixed with oil in correct ratio (for lawn mower above I used the gas from fall although it had gas stabilizer in it). Last fall when I was done with the trimmer I ran it until all gas was gone.
 

alpha1976

Forum Newbie
Joined
Apr 13, 2022
Threads
1
Messages
6
  • / Help- lawn mower making knocking sound and trimmer smoking white
another thing - it doesn't really smoke much or hardly any when idling. Smoke becomes apparent when I rev it. This was not the case last year or before. There is also some oil-like residue around the muffler. See attached pic.
 

Attachments

  • 20220414_174050.jpg
    20220414_174050.jpg
    672.9 KB · Views: 5

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,768
  • / Help- lawn mower making knocking sound and trimmer smoking white
If it clears up, just a couple of puffs, I wouldn’t worry about it. Left over fuel will collect water, even with stabilizer and an empty tank will contain moisture over the winter.
 

Tinkerer200

Well-Known Member
Joined
Mar 14, 2015
Threads
4
Messages
913
  • / Help- lawn mower making knocking sound and trimmer smoking white
Welcome from east central Illinois,

Walt Conner
 
Top