Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min

kosoku

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  • / Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min
Hi all,

I've been asking mower/small engine questions on the car forums I frequent, and I'm glad to have found a specific forum for this. :)

My 5-6 year old Craftsman walk behind self-propelled mower is having woes. It starts and runs like a brand new mower, thanks to a recent tune-up that included a deep-cleaning of the carb (removed and soaked in carb cleaner overnight), a new spark plug, air filter, and sharpening of the blade.

The problem is, after 15-20 minutes of mowing, the mower abruptly dies. No sputtering or warning, it just instantly shuts off as if I released the throttle lever (sorry, don't know the proper terminology).
Once I let it cool down for 1-2 hours, it starts right back up and runs like a champ... for another 20 minutes.

This means my 1 hour mowing job requires 6-7 hours. I love my mower and want to keep it a lifetime if possible. It's perfect for my size yard.
Can anyone offer some possible culprits? I have read where a faulty gas cap (vent) can cause similar problems. However, when I remove the gas cap after it stalls, it still will not run.

Thanks in advance for any advice.
 

JDgreen

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  • / Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min
Hi all,

I've been asking mower/small engine questions on the car forums I frequent, and I'm glad to have found a specific forum for this. :)

My 5-6 year old Craftsman walk behind self-propelled mower is having woes. It starts and runs like a brand new mower, thanks to a recent tune-up that included a deep-cleaning of the carb (removed and soaked in carb cleaner overnight), a new spark plug, air filter, and sharpening of the blade.

The problem is, after 15-20 minutes of mowing, the mower abruptly dies. No sputtering or warning, it just instantly shuts off as if I released the throttle lever (sorry, don't know the proper terminology).
Once I let it cool down for 1-2 hours, it starts right back up and runs like a champ... for another 20 minutes.

This means my 1 hour mowing job requires 6-7 hours. I love my mower and want to keep it a lifetime if possible. It's perfect for my size yard.
Can anyone offer some possible culprits? I have read where a faulty gas cap (vent) can cause similar problems. However, when I remove the gas cap after it stalls, it still will not run.

Thanks in advance for any advice.

EXCELLENT first time post...very detailed, very informative. When I first read the symptoms I too wondered about the fuel tank cap being vented. What you refer to is the deadman control and not the throttle lever. First, try this:

See if you can get a little more tension on the cable that the deadman control has, by that I mean try to stretch if further by rerouting it or maybe putting something under the wire so it has more tension. It may be the cable has so much play in it now that after some running time things get hot and the deadman control cable no longer operates properly.

Secondly, next time it stalls on you, tape or wire the deadman control down, then remove the spark plug and see if you get spark after grounding the plug electrode and pulling the starter rope. If you have good spark, that will mean your fuel system might be the problem. If spark is okay, squirt some fuel into the plug hole, reinstall the plug, and pull it over. If you get some combustion, the problem is likely in your fuel system, not electrical. Hope this helps.
 

kosoku

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  • / Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min
Thanks for the reply!

You know, you may be onto something with the deadman control cable.
I went out and removed the spark plug then grounded it to the engine. I had my wife try to start it, and I couldn't see any spark. Which got me thinking - perhaps the lever that connects the control cable to the carb was heating up, then stretching. I tinkered around with that lever (it's basically a thick-gauge wire) trying to tighten it. Not sure if I did anything, but the mower did start when I put the plug in.

I'm thinking it will have the same problem next time I mow, but I'm not sure what I should be replacing. I'm going to dig up the manual online and see what the parts look like.
 

JDgreen

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  • / Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min
Thanks for the reply!

You know, you may be onto something with the deadman control cable.
I went out and removed the spark plug then grounded it to the engine. I had my wife try to start it, and I couldn't see any spark. Which got me thinking - perhaps the lever that connects the control cable to the carb was heating up, then stretching. I tinkered around with that lever (it's basically a thick-gauge wire) trying to tighten it. Not sure if I did anything, but the mower did start when I put the plug in.

I'm thinking it will have the same problem next time I mow, but I'm not sure what I should be replacing. I'm going to dig up the manual online and see what the parts look like.

My walk behind push mowers all have an L shaped, spring loaded metal lever that has a hole in it, and the deadman control cable end has a "J" shaped ferrule (sp?) that fits into the hole, and there is basically no way to adjust the cable. They would rather you buy a new cable (about $23) than adjust the one you have. Disclaimer: Any risk you take following this idea is just that, your risk...LOL :eek:

Get a length of wire, such as a section of 14 gage ground (bare copper) electrical wire, and if possible, attach one end to the engine part of the deadman control, then move the deadman control all the way to the stop (against the spring tension) and wrap the copper wire around some part of the handle where it will not lose tension. Start the engine, and using EXTREME care, see if the engine will keep running for a half hour with the deadman control locked down. If it does, you have found the problem. A replacement cable should be the proper fix. NOT MY SUGGESTION !!! :eek:
 

kosoku

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  • / Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min
Well, I ran into the same problem today. It seems on my mower, the deadman control cable connects on the engine side to a lever with a large spring attached. That lever on the other end has what looks like a brake pad that forces the engine to stop when the control cable is released. Also on that same lever, there is a tab that depresses a black kill switch. I imagine that is what is controlling the spark to the engine. Lastly, this main lever has another tab that connects to another bracket with a spring that holds a lever down on the choke lever. This allows the choke to stay on briefly just while the engine is starting.

Here's what I tried today. As soon as the engine died, I took a peek at the portion that is visible with the flywheel cover attached. This is just the choke lever. Everything else is hidden when the cover is on. I tried, just for kicks, wedging a penny underneath that arm that holds the choke down (preventing it from touching the choke). At the time I thought it may be some kind of electrical contact switch, so I just rigged it not to touch. Anyhow, for some reason this worked. The mower started right back up. Then I mowed about 5 feet and the penny came loose, engine died immediately.

After this I removed the flywheel cover and saw what I described in the first paragraph. From there, I took the main lever on the engine side of the deadman cable and secured it down with a zip tie. This effectively did the same thing as having the cable fully activated. No good. I tried disconnecting the choke lever and keeping it off, no good.

I'm getting quite confused now. Once I got the flywheel cover off, everything looks to be in order underneath. Is it possible the electrical switch (looks like a push button/lever switch) is faulty, and that it overheats and stops working after 20 minutes? I don't really want to go throwing parts at the mower randomly. My wallet can't take that right now. Is there a way to "jump" the contacts on the switch where it thinks the deadman cable is always depressed? If that fixed the problem, I would of course replace the switch. I just want to rig it up to see if that is indeed the cause.
 

kosoku

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  • / Craftsman Self-propelled Mower w/ Honda 5.5HP engine stalls after 15-20 min
So I've searched the forum to no avail... I'm thinking it is that switch that is malfunctioning, but I just want to be able to temporarily bypass it to verify. What kind of switch is it? Will grounding the connector do the trick? Or just unplugging it?
 
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