Surging Engine

[coopns]

Husqvarna ride on, about 20 years old.

Recently I noticed there is a pause like in the engagement of the engine/cutting. So I have it going full speed, then there is a noticable
sound in the engine and the cutting slows but still cuts then I hit a clear patch and it seems like it gathers momentum and the engine
goes full speed again. So when I hit any sustained stretch of grass engine slows till I hit a section of longer grass (and really not long grass).

 

[MurkyAsparagus]

Sounds to be either really wet tall grass that is bogging the engine down or a carb issue.

Does it surge at all at idle? When was the last time you did a full tune up/maintenance?

 

[Lubener]

I would make sure that accumulated grass under the engine cover is not hindering proper operation of the governor mechanism and linkage. Otherwise, there could be a dirt issue within the carb.

 

[grasscutter]

A surging engine is usually always attributed to a lean condition.

A lean condition occurs when there's a blockage in the carburetor.

Carburetors get contaminated very easy.

You must keep the fuel absolutely sterile.

 

[siriusc1024]

Clogged pilot jet.

 

[BigCahuna]

Here's my go to method of helping a tired engine out without rebuilding, or replacing it. First pull the plug. Clean it or replace it. Second, clean or replace the air filter. Third,make sure your using fresh new gas. Not stuff leftover from last season. Before I fill my gas cans, I throw a few ounces of carb cleaner in, as well as a few ounces of MMO. Run at least 1 tankful completely thru the engine. If you have a tach, they are cheap on ebay, check to be sure the engine is running at the proper rpms. Sometimes the governor becomes mis adjusted, and might need a tweak. Also make sure there's no grass built up on the underside, and there's nothing like an odd piece if rope wrapped around the blade. Good Luck.,,

 

[nbpt100]

All good advice here. A lean condition can also be caused by an air leak in the intake. Make sure everything is tight. Also make sure the choke is fully off when you are running. That would cause a loss in power. Any noticeable smoking at start up or under load?

 

[ripcord]

A restricted fuel filter can also cause lean running.