Yard Machine 650 3.1 Lawnmower power loss

Hello,

I have a Yard Machine 650 lawnmower that until a few days ago ran fine.
It starts fine, but the power is weak. Almost to the point of cutting off.
I changed the spark plug and added oil because it was very low. I haven't checked the carb or any filters. The one thing that may give a clue to what's going on is that when I tilt the mower forward (45 degrees) the power seems to get stronger. As soon as I put it back down the power is weak again. Any ideas what's happening?

Thanks,
Troy

 

Sounds like carburetor issues. What engine is on it?

 

Briggs & Stratton 650 series

 

Kind of hard to know what you're describing. I guess you mean it speeds up when you say the power "seems to get stronger" when you tilt it? You haven't checked the air filter yet?

 

Sorry. No I haven't checked the filter or the carborator yet. I will do that this weekend. Yes, when I tilt the mower forward 45 degrees the engine revs faster (normal). As soon as I put it down it slows down like it wants to cut off.

 

If it's not the air filter, let us know and we'll go from there.

 

Really would be helpful if you would post the engine model, type and code numbers, the series 650 doesn't tell much. Have a good one. Geo

 

Also try loosening the gas cap.

 

Added new filter and no difference. I would change the fuel filter, but can't seem to find out where it's located. The engine still continues to get stronger when I tilt the mower forward 45 degrees. Any ideas? Also I have attached a pic with the mower info. Thanks for the help.

 

Sounds like there is maybe some water in the carb. You'll need to remove the carb bowl and clean it out. The engine model number should be stamped on a plate of metal that shields over the top of the muffler.

 

If you can't find the engine info, post the complete mower model number maybe we can find the engine through it. Have a good one. Geo

 

Here's the model #: 11A-546B029959633

This # was on top of the mufler housing:
126T02-0454-E1 06091256

Hope this helps.

Troy

 

The muffler number is the right one. I still think it's water or something in the carb.

 

It could be water as Cheese says but I would think it would die when it drank some water. The "O" ring behind the carb has a tendency to fail when they get old and create a air leak or the carb bolts could be loose also the bowl nut is the main jet for the carb maybe it has a piece of junk partially blocking it. First make sure the carb bolts are tight, while it is running spray/dribble some carb/brake parts cleaner behind the carb where the carb and block meet, if the engine tempo changes you have a leak and need to replace the "O" ring. Clamp off the fuel line, remove the carb bowl, check for water droplets in the bottom of the bowl, clean the bowl nut, a hole down through the center and one across the bottom. Set a container under the carb and release the clamped fuel line to let some fuel flow, check the fuel for water and other junk, it will accumulate at the bottom. Reassemble and let us know what happened. Have a good one. Geo

 

Thanks Guys! I will check this out asap.