Lawn Boy engine surges

larryq22 · 04-14-2009, 03:27 PM

I have a Lawn Boy Silver Series mower, 4-cycle engine, Model 10335. I am using fresh gasoline. Lately the mower has been surging - for example, when I cut the grass it alternately roars with power then idles for a few seconds. If I leave it running while standing still (say on the sidewalk) it does the same thing and eventually it quits running altogether.

Last season I brought it to a shop and he adjusted the governor (wherever that is) and it worked well. Last week I had to re-insert the spark plug wire into the cable (pierced the rubber shaft until it hit copper.

Any ideas what is wrong or how to fix it?

Thanks,
Larry

coleman mobile · 04-23-2009, 07:14 PM

do you know what engine it has?

k2skier · 04-23-2009, 10:08 PM

They use Tecumseh's. It's running lean, carb needs a cleaning and a kit.

dai · 04-24-2009, 12:20 AM

check the float does not have a pin hole in it

Volt-Schwibe · 04-24-2009, 03:09 AM

I had a lawnmower here that was surging real bad too, it turned out to be a bunch of condensation in the carb, inside the various chambers it has. I had to completely open it, and wash it and let it dry completely. Then when i put it back together, it was perfect.

On the other hand, we have a tractor here that has a governor problem that comes back all the time, so i have to constantly adjust the governor settings, what is perfect one day won't work at all the next day.

So, it could definately be either. Or it could be running lean as suggested. To test this, you'll see that the carb has dual linkage, one is actually connected to the governor, and one is spring loaded off of that one, and connects to the throttle control. With the engine running, carefully grab the rod connected to the governor, and try to hold it perfectly still. If you can get it to run smooth, then it's not a carb problem at all, it's in the governor adjustment.

I've found over the years, it's really hard to do any carb work on these motors with the governor in place, so i usually disconnect them entirely while i'm working on them. Once i have them running like a top, that's when i mess with reconnecting the governor, and setting it is alot simpler when you know the engine is running great. I usually make a little throttle pull handle with a paperclip.

clowe · 05-05-2009, 04:25 AM

If it is a 2cycle you will need to clean intake/exhaust ports.carb an adjust side screw if it have one and airvane or governor.

04-14-2009, 03:27 PM	#1 (permalink)
larryq22 Registered User Join Date: Apr 2009 Posts: 3 OS: windows vista sp1	Lawn Boy engine surges I have a Lawn Boy Silver Series mower, 4-cycle engine, Model 10335. I am using fresh gasoline. Lately the mower has been surging - for example, when I cut the grass it alternately roars with power then idles for a few seconds. If I leave it running while standing still (say on the sidewalk) it does the same thing and eventually it quits running altogether. Last season I brought it to a shop and he adjusted the governor (wherever that is) and it worked well. Last week I had to re-insert the spark plug wire into the cable (pierced the rubber shaft until it hit copper. Any ideas what is wrong or how to fix it? Thanks, Larry

04-23-2009, 07:14 PM	#2 (permalink)
coleman mobile Registered User Join Date: Apr 2009 Location: wisconsin Posts: 7 OS: vista	Re: Lawn Boy engine surges do you know what engine it has?

04-23-2009, 10:08 PM	#3 (permalink)
k2skier Registered User Join Date: Sep 2008 Location: Oregon Posts: 313 OS: XP Home-SP3 My System	Re: Lawn Boy engine surges They use Tecumseh's. It's running lean, carb needs a cleaning and a kit.

04-24-2009, 12:20 AM	#4 (permalink)
dai Manager, Hardware Forums Join Date: Jul 2004 Location: west australia Posts: 56,499 OS: win 7 32x 64x rtm	Re: Lawn Boy engine surges check the float does not have a pin hole in it __________________

04-24-2009, 03:09 AM	#5 (permalink)
Volt-Schwibe Asst. Manager, Automotive Forums; HJT Trainee Join Date: Jan 2003 Location: Behind you, watching you as you type. Posts: 7,372 OS: Click "My System" to view details My System	Re: Lawn Boy engine surges I had a lawnmower here that was surging real bad too, it turned out to be a bunch of condensation in the carb, inside the various chambers it has. I had to completely open it, and wash it and let it dry completely. Then when i put it back together, it was perfect. On the other hand, we have a tractor here that has a governor problem that comes back all the time, so i have to constantly adjust the governor settings, what is perfect one day won't work at all the next day. So, it could definately be either. Or it could be running lean as suggested. To test this, you'll see that the carb has dual linkage, one is actually connected to the governor, and one is spring loaded off of that one, and connects to the throttle control. With the engine running, carefully grab the rod connected to the governor, and try to hold it perfectly still. If you can get it to run smooth, then it's not a carb problem at all, it's in the governor adjustment. I've found over the years, it's really hard to do any carb work on these motors with the governor in place, so i usually disconnect them entirely while i'm working on them. Once i have them running like a top, that's when i mess with reconnecting the governor, and setting it is alot simpler when you know the engine is running great. I usually make a little throttle pull handle with a paperclip. __________________ <signature> TSF is funded by our Admin's pocket, care to help? Power Tip: Subscribe to your thread (Thread Tools) to receive an instant email notification when you get a reply. New Members: Creating a single new thread in the correct section is the best way to assure your thread will receive a reply. </signature> Last edited by Volt-Schwibe; 04-24-2009 at 03:16 AM.

05-05-2009, 04:25 AM	#6 (permalink)
clowe Registered User Join Date: Dec 2008 Posts: 11 OS: xp	Re: Lawn Boy engine surges If it is a 2cycle you will need to clean intake/exhaust ports.carb an adjust side screw if it have one and airvane or governor.