Craftsman Mower Dies, What can it be?

[SR77]

thanks again for the replies!

ok heres what i did. Took the carb off cleaned it out completly, bought a rebuild kit for it and replaced the needle and seat, gaskets etc. The gas tank was cleaned out and it has a new fuel line on it. I bought a new spark plug for it too and gapped it per the manual and got a new air filter. Cleaned the engine and put it all back together. started it up in one pull and ran great for about 20 mins and I thought it was fixed. Then it started to sputter again and died!!!!! And I could not get it started. Pulled the plug to check for spark and looked like there was some spark.

So here is my question for you guys, can a bad coil still spark but maybe the spark is weak or intermitten? I am running outta options here. I can't figure out why it dies out. I have cleaned everything and replaced all the maintenance items including rebuilding the carb and it still continues to not run after a while. If its not a bad coil I am lost! thanks again for you help. I am close to going shopping for a new tractor!!!!!

 

[VicL]

Originally Posted By: SR77
thanks again for the replies!

ok heres what i did. Took the carb off cleaned it out completly, bought a rebuild kit for it and replaced the needle and seat, gaskets etc. The gas tank was cleaned out and it has a new fuel line on it. I bought a new spark plug for it too and gapped it per the manual and got a new air filter. Cleaned the engine and put it all back together. started it up in one pull and ran great for about 20 mins and I thought it was fixed. Then it started to sputter again and died!!!!! And I could not get it started. Pulled the plug to check for spark and looked like there was some spark.

Here's a troubleshooting idea: Run this test again. Once the lawn mower dies, immediately pull the plug and check. It its wet, then its a bad coil. If its dry, fuel blockage of some sort.

Vic

 

[greenaccord02]

Good point, VicL.

I'm hesitant to believe all these bad coils that we've seen lately have all been bad coils. I'm not saying it doesn't happen, but it's been my experience that it's a rare failure.

 

[01rangerxl]

Originally Posted By: greenaccord02
Good point, VicL.

I'm hesitant to believe all these bad coils that we've seen lately have all been bad coils. I'm not saying it doesn't happen, but it's been my experience that it's a rare failure.


It is kind of an unusual problem. Coils do fail, but carb problems are much more common.

With B&S engines, the ground wire for the coil is often the culprit. It rests against the engine, and sometimes when they get hot the insulation melts and the ground shorts out.

Keeping everything clean under the engine cover will go a long way towards preventing coil problems. They get covered in dirt, get too hot, and then have problems. Whenever there is an ignition issue, always check the ground wire first though.

 

[SR77]

thanks again for all the help

Unfortunately I am getting no where yet. I took off the engine cover again and cleaned the entire engine. Took off the coil and cleaned it too and the ground wire looked like it was still in tact. The mower looked brand new again, started up one pull from cold and ran fine again for about 10 mins and then died again. Pulled the plug to check for spark again while it was hot and there was spark so it doesn't look like the coil. When it dies it does surge and sound like it is running out of fuel for about 20-30 seconds then it dies. I just don't understand what it could be. I have cleaned out the fuel tank and put a new cap on, put a new fuel line on and taken the carb completely off cleaned it the best I could, put a new needle and seat and new gaskets on. I am lost, if it is fuel related what else is there other then buying a new carb for it? This little motor is so frustrating! thanks again

 

[boraticus]

I'm not familiar with the carb on your mower but can it be completely disassembled? Can the jet(s) be pulled? Can you pull the float needle to inspect the float needle seat? Can you see the tiny orifices in the carb body that might need to be blown out? To properly clean a carb, it has to be taken down to it's smallest parts.

I've yet come to across a carb that didn't work properly just from a thorough cleaning.

Have you tried a replacement spark plug. Not long ago, I had a chainsaw that I thought might have needed a carb kit. I changed the plug and problem solved.

 

[oily boyd]

The next time it starts to surge (but before it quits), remove the gas cap and see if that helps.

 

[yeehaw1960]

Did you thoroughly clean the bowl nut? The hole down through the middle should be unobstructed and the hole that goes all the way through from side to side should be the same.

After you take off the air cleaner housing, look at the face of the carb, you will see a little round brass area. The hole through it should be clear as well. A stripped bread wrapper will fit in there perfectly. Send us a pic of the carb and we may be able to help better.

IF you didn't COMPLETELY empty and blow out the gas tank, there could still be water in it. When you take the carb bowl off, is there any beaded liquid in it? That would be water.

Not trying to treat you like you're dumb. These things can be really frustrating.

 

[SR77]

thanks guys

The mower is one of these craftsman no manual choke or throttle carbs, just pull the cord and it does the rest, so the carb is pretty basic. When I pulled the carb I cleaned the bowl out, the bowl nut and all the holes in it and I sprayed carb cleaner in all the other holes like the air bleeds etc. in the carb. Stuck a paper clip in all holes as well to clear then out. Put a new needle and seat in and made sure the float was working without sticking. Cleaned the entire outside of the carb as well and put it all back together. Fuel tank was emptied and cleaned/flushed out and a new fuel line was put on along with a new cap. Spark plug was replaced as well and gapped prperly. The only other thing I can think if it is a carb issue is to either get it dipped ($30) or buy a new one ($50). I will try pulling the gas cap off the next time I run it,

 

[charbaby]

All good advise. Mine was doing something similar. It would start fine after a couple of pulls when (((COLD))) and would run til I, myself, shut it off but, would not restart when "HOT". It never stalled out!

I pulled off the top cover to expose the flywheel and coil. I lightly sanded and cleaned the surface rusted flywheel and reset the coil using a matchbook as a guide. Changed the sparkplug as there may have been a slight crack in the ceramic insulator that I couldn't see. Never had another issue. Sold it this past Spring/Summer for $50. Ran great using MMO and StaBil in the gas for lube.

 

[SR77]

We have a winner, Oily Boyd was right on. Loosened the gas cap as soon as it started to stumble and the idle went right back!!! Good job Boyd, thanks! I have been chasing this problem down for a month.

So now heres my question, are these plastic gas tanks vented somewhere or is the actual gas cap vented? I am wondering why this problem would pop up now. I do have a new standard gas cap on it but i was having this same issue with the old cap. How do these tanks get vented?

 

[oily boyd]

Glad to hear you found it. I have never seen anything but the vent built into the cap FWIW.

Maybe you can find the correct cap at Sears or go to a repair shop; I'll bet they'll have just what you need.

 

[Warstud]

There's a tiny hole in the middle of the gas cap. You can try blowing it out with compressed air.

 

[VicL]

Those caps should be easy to find. Sears, Lowes, possibly even WalMart... just check their lawn mower supply section.

Vic

 

[tmorris1]

In your original post you stated that you changed the gas cap. Is the new one bad then because that was my first guess (bad vent).

 

[SR77]

Yes, I have a new cap on it. I got it from a buddy of mine at a local mower shop. I have to check why it is not venting the tank.

 

[boraticus]

Just goes to show, always do the easy stuff first, check on switch, check gas cap, check spark plug, check fuel flow etc.....

 

[tmorris1]

Originally Posted By: boraticus
Just goes to show, always do the easy stuff first, check on switch, check gas cap, check spark plug, check fuel flow etc.....

That was my point... He said in his initial post that he had changed the gas cap. Was it a bad cap or did he really not change it.