Briggs 40H777-0134-B1 Surging

[StarTech]

Here's one for the books.

Customer changes his deck belt due to failure. Engine was running fine before the belt change. After changing the belt the engine develops a surging issue. Just a just happen to happen after the belt change.

Several problems found.

1. Breather hose leaking. Replaced.
2. Fuel impulse hose getting ready to fail. Replaced.
3. Carburetor jets were loose so the carburetor got a complete cleaning and a kit installed.
4. Intake manifold o-rings harden. Replaced.

But none this was the root cause. So what was the root cause? Not ignition, timing, or valve issue. The problem is/was with carburetor. I can kick myself for not catching it during the carburetor rebuild.

 

[Auto Doc's]

Hi Star Tech,

Don't beat yourself up. Anyone who has worked on carburetor equipment (even for many years) knows that things do not always go as planned.

I had a similar issue on a generator recently, but it turned out that the tank filter screen had become gummed up from old/poor quality fuel. That took me half a day to finally figure out and that was after going through the carburetor twice and finally replacing it with a known good one.

 

[StarTech]

I would think not many of us had a choke to cause surging.