Today I was out mowing the lawn with my Husqvarna YT42XLS when it started to surge very drastically. The engine was acting like it was about to stall but would rev up again right before it would turn off. I've been having similar issues with the mower stalling on me recently so I decided to do some research on what the issue could be. The particular article I read recommended that I clean my air filter and check my spark plugs so I did just that. I cleaned the air filter no problem, checked the first spark plug with no issue, but when I went to check the second spark plug I realized that the spark plug wire wasn't even attached to the plug. I pushed the wire onto the plug and started the mower up, I bought this mower used a couple months ago and it had never ran as good as it did when I put that wire on the plug so I'm assuming it has been disconnected since the moment I bought it. I thought that my problem was fixed after that but after another 20 minutes or so of mowing the engine started to surge sporadically again. Is there long term damage to the engine due to the spark plug wire being disconnected and that is what's causing the surge? Or is there anything else that could be causing the engine to surge like this? I apologize in advance if any of my questions are dumb, my knowledge of small engines or engines in general is extremely limited. Any advice would be appreciated, thanks!
I've been using my yard tractor with one of the spark plug wires disconnected.
- Thread starter Bknapp
- Start date
bertsmobile1
Lawn Royalty
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- Nov 29, 2014
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:welcome::welcome::welcome:
If you had searched the forum using the word "surging"
You would have gotten about 500 pages with 50 threads per page.
And funny enough surging of a governed engine is the same regardless of the brand of engine, size of engine & mower it is fitted to.
Surging on a governed engine is always caused by insufficient fuel to be able to maintain a constant speed
There are two ways this can happen
1) air entering after the main jet has metered the correct amount of fuel for the volume of air passing over it
or
2) there is not enough fuel for the main jet to meter the correct amount of fuel for the volume of air passing over it
You check for the first by saturating the area between the carburettor & the engine with something like WD 40 from a trigger pack.
You do not use a pressure pack can of anything because the propellent is highly volatile so a stray spark can cause a nasty Whoooof.
In your case, an air leak is highly likely caused by the mower being run on one cylinder for extended periods.
There is a better than average chance that the manifold has warped and might require replacing, particularly if it is one of the plastic ones.
The other requires you to first check there is enough fuel getting to the carb then cleaning the carb .if necessary
let us know how test 1 goes so we can walk you through checking the fuel supply side.
Some like to start at the carb & go back to the tank
I like to go the other way mainly cause I am lazy & busy so pulling down a perfectly running carb for no good reason is something I have learned to avoid.
If you had searched the forum using the word "surging"
You would have gotten about 500 pages with 50 threads per page.
And funny enough surging of a governed engine is the same regardless of the brand of engine, size of engine & mower it is fitted to.
Surging on a governed engine is always caused by insufficient fuel to be able to maintain a constant speed
There are two ways this can happen
1) air entering after the main jet has metered the correct amount of fuel for the volume of air passing over it
or
2) there is not enough fuel for the main jet to meter the correct amount of fuel for the volume of air passing over it
You check for the first by saturating the area between the carburettor & the engine with something like WD 40 from a trigger pack.
You do not use a pressure pack can of anything because the propellent is highly volatile so a stray spark can cause a nasty Whoooof.
In your case, an air leak is highly likely caused by the mower being run on one cylinder for extended periods.
There is a better than average chance that the manifold has warped and might require replacing, particularly if it is one of the plastic ones.
The other requires you to first check there is enough fuel getting to the carb then cleaning the carb .if necessary
let us know how test 1 goes so we can walk you through checking the fuel supply side.
Some like to start at the carb & go back to the tank
I like to go the other way mainly cause I am lazy & busy so pulling down a perfectly running carb for no good reason is something I have learned to avoid.
