Craftsman LT4000 spitting/sputtering and backfiring after riding for 5mins

[cjones636]

I Have a Craftsman LT4000 Riding lawnmower with the kohler cv14s engine. Late in the year last year it started spitting, sputtering and backfiring then would die. It would do this after about an hour of mowing. If i tried to start it back up, it would backfire loudly. If i waited 10 mins, it would start back up and i could finish my work.

Now, it will do the exact same thing mentioned above, but it's happening more frequently, like ever 5mins!

I've changed plugs and checked the spark with a voltage meter and by placing the plug up against the engine, and it had a nice strong blue spark.

I Carried my voltage meter with me, and when it died i jump of and checked the voltage again, and everything was good.

A Mechanic told me it was the safety switches shortening out, so i disconnected all of them and it's still happening.

I Check the fuel shutoff solenoid on the bottom of the carb and touched it to the engine and the plunger worked good!

I Also removed (now replaced) the fuel shutoff solenoid with a bolt, some washers and a gasket (to make sure it wasn't faulty) and it still doing the samething.

Today, i rode it around until it started spiting and sputtering and checked the voltage on the battery, and it checked out fine.

When it starts spitting and sputtering, if i move the choke under middle ways, it will stay running without spitting and sputtering, and then i can slowly move the choke back up to the mowing position and it will run, but as soon as i engage the blade again, it will start spitting and sputter again, so i will have to disengage the blade and it will stay running half choke.

 

[davbell22602]

Sounds like carb needs cleaned out and overhaul kit put in it.

 

[cjones636]

Sounds like carb needs cleaned out and overhaul kit put in it.

Can you link me to the overhaul kit (if allowed)?

 

[motoman]

Does it have hydraulic lifters? If not the pros may say check valve adjustment . My Intek did that before valve train failure.

 

[davbell22602]

Can you link me to the overhaul kit (if allowed)?

Need your numbers thats on the flywheel cover for rebuilt kit.

 

[cjones636]

Here is a video that i took Saturday while riding using this mower. I Wanted to show what was happening so some expert could tell me whats up.. I Just figured out how to get the video off my phone :laughing:

 

[cjones636]

Here is a video that i took Saturday while riding using this mower. I Wanted to show what was happening so some expert could tell me whats up.. I Just figured out how to get the video off my phone :laughing:

Anyone think the carb is the issue here? I Would think it would run like crap when started if it was the carb. It runs fine up until 5 mins of mowing then it starts doing whats in the video. You think i should take it off the carb and clean it real good without the rebuild kit?

 

[BustedKnuckles]

I don't have speakers at work so I skipped the video.

If moving the choke lever changes the conditions, I would suspect a dirty fuel bowl. I would change the fuel line (if hard and brittle feeling), install a new fuel filter and remove the carb bowl to clean it and the jet both (use wire or a toothpick). Check the float while your there and make sure the needle moves freely. I would use come carb cleaner to spray through the fuel inlet (both ways) to make sure any debris is not left behind. Re-install and verify the repair.

Good luck!

 

[Fish]

Run it until it acts up again, then reach back and take off the fuel cap and see if it evens back out.

 

[cjones636]

Run it until it acts up again, then reach back and take off the fuel cap and see if it evens back out.

I Already done that, it didn't help.

Here some new information regarding this.. Today i said to myself, i'm going to try something. You know, on the throttle where it says "Here for mowing" (even with the rabbit)? Well, i took the throttle and moved it down just a **** hair and it ran for a solid hour! Then i went up to the upper field to mow it, and moved the throttle back up to the normal mowing position and made 3 passes and she started spitting and sputtering, died, than backfired!

I Finally got it started back after a few mins of cussing and kicking the wheel, and it would just not run for long no mater where i moved the throttle too!