push mower surging...

[stackz88]

ok, my neighbor gave me his old push mower (the newer briggs ones with the plastic carb) for free.

when you crank it, it runs ok for a second or two and then starts that old familiar surging.

I grabbed a new plug and the fuel pump diaghram set from the local truevalue as its usually the paper fuel pump diaphram that stretches out.

replaced both and it started doing it again as soon as it cranked up. where else should I look at for this surging problem?

 

[waterinthefuel]

Re: push mower surging...

The governor is messed up. The spring might be weak, something. If you mean surging meaning the RPM's fluctuate up and down, but without the engine missing or anything, it's the governor.

 

[stackz88]

Re: push mower surging...

isnt the governor just the thing that goes across the back of the engine and shuts the stator down when you want to turn it off?

 

[MTboatguy]

Re: push mower surging...

All small engines in mowers, snowblowers, etc have a governor to regulate RPM's and they go weak or break, see if you can find a diagram of the engine you have and it should show the governor location.

 

[BF]

Re: push mower surging...

My B & S mower starts surging when it's time to replace the air filter... try starting it without the air filter for a minute. but otherwise, as said above, could also be a governor prob.

 

[stackz88]

Re: push mower surging...

just looked at the pic I snapped on my droid of the carb setup on it (I like to have one when browsing youtube, etc) and it does look like the retention spring for the governor has been stretched/broke/restretched before. dont know why I didnt notice that before.

guess I'll see if I can find another spring today at lowes while I'm there picking up some treated plywood.

 

[scipper77]

Re: push mower surging...

This is a common symptom of a dirty carb. Is it running lean or rich?

I actually am going through the same thing with my snowblower but in my case the prognosis is far worse. It turns out I have a small head gasket leak. Because I have been running it that way before I knew what was going on I have probably "burned" my head. It went from a $7 head gasket and a couple hours of my time to well see what can be done after I tear down the motor.

 

[lckstckn2smknbrls]

Re: push mower surging...

Try running some Seafoam in the fuel.

 

[stackz88]

Re: push mower surging...

got it running good. turns out really was the stupid return spring on the governor. I just clipped off the original end and straightened out a single coil to use for a new end and it cranks up and runs perfectly now.

thanks guys!

 

[scipper77]

Re: push mower surging...

Very glad this had a happy ending.