Engine Sputters after adding new gas


  #1  
Old 06-22-24, 05:58 PM
D
Member
Thread Starter
Join Date: Jul 2015
Posts: 42
Upvotes: 0
Received 1 Upvote on 1 Post
Engine Sputters after adding new gas

I have a Gravely zero turn mower. Whenever I fill it up with gas, for the next 10 minutes or so, the engine sputters like itís about to die but it never does. After about 10 minutes of doing this it runs fine. Any idea what could be causing the sputtering? Thanks!
 
  #2  
Old 06-22-24, 06:11 PM
M
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,867
Received 37 Upvotes on 36 Posts
If it was running well before and you didn't run it out of gas it's likely the gas in the carb over heating. That would create a vapor lock which would correct itself with cooler fuel by running.
 
  #3  
Old 06-22-24, 07:15 PM
D
Member
Thread Starter
Join Date: Jul 2015
Posts: 42
Upvotes: 0
Received 1 Upvote on 1 Post
Thanks! Do you know what might be causing the gas to over heat or what the fix might be? It spits out black smoke when it starts to die, Iím not sure what that means.
 
  #4  
Old 06-22-24, 08:39 PM
M
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,867
Received 37 Upvotes on 36 Posts
Just a matter of the gas in the carb bowl heating up when the hot engine is stopped. Some of the fuel will vaporize and give you a rich mixture

Far as a fix, I'm not sure. A different fuel or an additive, but I can't point you on either. Some guys shield the lines and carb bowl with tinfoil. Then you see hundreds of mowers with no problem.
​​​​​​



​​​​​​
​​​​
 
  #5  
Old 06-22-24, 08:46 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,043
Received 156 Upvotes on 142 Posts
Does this just happen after the engine is hot, or any time you fill the tank? If you shut the mower off and don't refill it, does it start back up without the sputtering? What if you shut it off, take the gas cap off, put it back on, does it start and run fine then?
 
  #6  
Old 06-23-24, 03:39 AM
D
Member
Thread Starter
Join Date: Jul 2015
Posts: 42
Upvotes: 0
Received 1 Upvote on 1 Post
This happens any time I take the gas cap off and fill the tank. It doesnít matter if itís been sitting for a week and I fill it up before I start or if Iíve been on it for a couple hours and I need to refill it. Once it gets going, I can shut it off and start it back up and it doesnít do it. But as soon as I take the cap off and refill it it sputters. I havenít tried taking the cap off but not refilling it. I get the no ethanol gas from QuikTrip.
 

Last edited by dthryno23; 06-23-24 at 04:34 AM.
  #7  
Old 06-23-24, 06:27 AM
M
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,867
Received 37 Upvotes on 36 Posts
OK. If it does it cold or hot, that's not hot fuel, obviously. Not sure what you have.
​​​
Everytime on a cold engine would bring the choke to mind and a hot engine, just as been described. The black smoke is rich mixture however it comes about. Simply adding gas as the problem, I doubt.
​​​​​​
 

Last edited by marbobj; 06-23-24 at 07:12 AM.
  #8  
Old 06-23-24, 08:08 AM
D
Member
Thread Starter
Join Date: Jul 2015
Posts: 42
Upvotes: 0
Received 1 Upvote on 1 Post
The problem also seems to be more pronounced when the blades are engaged vs. when itís just idling.

i donít really know how these engines work. Is it possible some of the gas is leaking into the engine when I fill it up, maybe causing vapor lock at first until it warms up? I donít know if/how that would be possible but I was just trying to meld together some of the thoughts Iíve heard here, which I appreciate!
 
  #9  
Old 06-23-24, 09:08 AM
M
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,867
Received 37 Upvotes on 36 Posts
Is the engine fuel injected by chance?
That would be a different set of maybes..
 
  #10  
Old 06-23-24, 11:51 AM
M
Member
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,867
Received 37 Upvotes on 36 Posts
I see a Yamaha FI system on Gravelys. Those systems are similar to automotive. Bottom line is you need diagnostic equipment to point out what is bonkers. Otherwise it's a guessing game.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description: