Starts fine, but won’t rev

[Horse46 519]

Why does one problem always lead to another?

Since getting the old girl running, I did about five minutes of mowing and then the motor shut down, it fired back up no problem but I can’t get it to rev. On the one occasion it did rev up, as soon as I applied any load it just cut out, it idles fine and fires on the button. Any ideas??

[lynnmor 7,305]

Bad spark plug, dirty carburetor, bad fuel lines, bad fuel filter, air filter plugged, bad coil or wire, just a few of my ideas.  Check these things and check back.

[Pullstart 62,846]

Throttle cable or governor adjustment needed?

[wallfish 16,995]

To add to the above

A bad condenser or loose connections to it will allow them to idle but not increase rpm.

 

[Ed Kennell 38,163]

Does it rev up if you open the throttle plate manually?

[953 nut 55,212]

Presuming the engine in question is a Kohler with battery ignition type and has ignition points you should clean the points by running a brown paper bag between them while they are closed. Your ignition timing is adjusted by your ignition points, if the gap on the points is nor correct the timing will be off and it will not operate properly. The Kohler Service Manual on this site has ignition timing information.

 

[Horse46 519]

Thanks for the reply’s, I’ve had a look at the manual for carb and point settings, I adjusted the points the other day but set them to .012 but it’s supposed to be .020, this could be my problem? Also I’ve had a mess with the carburettor, so I’ll go back to the factory settings and see what I get. 
I’m working for the next few days so may not respond quickly. 

[Horse46 519]

13 hours ago, Ed Kennell said:

Does it rev up if you open the throttle plate manually?

Not really, sort of but not as it should. 

[Pullstart 62,846]

Oh yeah, .008” off could easily make it sluggish!

[Ed Kennell 38,163]

48 minutes ago, Horse46 said:

I adjusted the points the other day but set them to .012

Was there a reason that you set them at .012 instead of the .020 ?

[Horse46 519]

5 hours ago, Ed Kennell said:

Was there a reason that you set them at .012 instead of the .020 ?

Yeah, I thought that was what it was, I set them 5 or 6 years ago but my memory has obviously played a trick on me lol. 
They were not that far off .012 to be honest which is why I didn’t think it was wrong. 
At the end of last season it was running a bit off, it would start fine, run great for about 5 minutes and then it would cough and stutter for a couple of seconds spit a bit of black smoke and then carry on as normal. 

[953 nut 55,212]

The ignition timing was retarded at .012. The ignition took place after the piston reached TDC which made starting easy but lacked power. Glad you figured it out.

[ineedanother 1,369]

My guess is fuel. I would pull the fuel line from the tank to see if you can get fuel to run freely from the petcock and then chase the fuel to the carb. You could start at the carb and work back, but my bet is with the petcock being clogged.

[Horse46 519]

8 hours ago, ineedanother said:

My guess is fuel. I would pull the fuel line from the tank to see if you can get fuel to run freely from the petcock and then chase the fuel to the carb. You could start at the carb and work back, but my bet is with the petcock being clogged.

It’s getting fuel, I changed all the fuel line and filter, also pulled the pump as I had trouble with that before, thanks for your input though 👍🏻

[oldlineman 1,481]

I believe Richard nailed it.