Lawn mower engine repair.

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RickN

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Mods please move if a better location for this.

I have a John Deere JS48 mower that we spent $128 getting repaired shortly after I got out of the hospital. Problem was not fixed and it was returned for repair but still has the same problem. In will not stay running over a few minutes. The repair guy said it was the carb and that he repaired it.

I found new carbs for it on Amazon for around $20 and I am thinking for ordering one and trying to repair the mower myself before next spring. Is there anything I need to know or look out for? Kit includes the gaskets and I assume I will need casket sealer, anything else you can think of? I am not a good mechanic but I do a lot of repairs like rebuilding our dryer, replacing the hot water tank dip tube, etc, etc. Anyway I am willing to give it a shot since I will need to have work done on our riding mower before spring too.
 

Dumpstick

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Those Chinee carbs are hit and miss, in my experience. Many times they are made for multiple applications, and may not have the correct jets, etc installed.
Be prepared to tune the carb, it may not be plug and play.

What's the problem you're having ? If it's recurred, it probably wasn't repaired to begin with, or a symptom was fixed, not the root cause.
 

RickN

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Yep runs for maybe 2 minutes before dying. To me it acts like it is not getting fuel. I can even spray starting fluid in the carb and it will run until that is all used up then it dies.
 

swampratt

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No gasket sealer on carbs.
Fuel hoses possibly and make sure the air filter is not plugged up.
Cleaned and gaped spark plug of course.
Sometimes coils will get hot and weak.

Many riding mowers have a vented gas cap yours should also and that vented cap will clog and not allow gas to flow from the tank.
Check the vent hole in the gas cap first before anything.
Then retest if it is clogged and you unclog it.
 

2busy

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Just have to verify what the problem is first before throwing more parts at it. When it dies you need to see if it has spark at the plug, is it getting fuel to the cylinder. Only then will you know which route to take.
 

NightShade

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A lot of videos are out there on Youtube to walk through doing stuff. The carbs on the mowers are super simple and other than the float not shutting the fuel off or a jet being clogged there isn't a ton to do.

https://www.youtube.com/user/mustie1/videos does a TON of repair stuff on small engines. He almost always goes through the carbs.

If it runs and then dies my best guess is a stuck float and it's leaking a little fuel past at times and then uses that up and dies. My guess is five or ten minutes later it will start up again and run for a bit.

Pull the carb, take off the bowl and see if the float is freely moving. It my be binding on the pin or the needle may be getting stuck. The tab that the float has may also be at the wrong angle not allowing enough fuel in.

Gas cap could be holding a vacuum and may even be a bad line.
 

RickN

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I should have mentioned that it does it even with the fuel cap removed. In the next few days I will try blowing from the carb back to the tank and see if I can find anything.
 

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