300 lawn runs 20 mins then backfires and dies

   / 300 lawn runs 20 mins then backfires and dies #41  
coloradotrout said:
Replaced fuel pump. Maybe problem solved. I used a cheap $13 one from Amazon but it looks ok. We'll see.

Another issue - the rectifier is outputting -2v DC (yes minus). AC across its two terminals is 38v AC. I replaced the original Kohler awhile back. What DC should I see? I felt like issue with original one was too high of voltage and it damaged the battery. I'm guessing around 13v to 14v would be right.
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I suggest cleaning out the in-tank fuel outlet strainer before spending more time & money on stalling issue of your JD 300 (se my post #17 in this thread).

IMG_1655.JPG


PS. My JD 300 is 46 years old and the strainer had to be cleaned twice so far due to similar stalling as you described!
 
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   / 300 lawn runs 20 mins then backfires and dies
  • Thread Starter
#42  
My fuel pump was bad, but the filter could use a clean I'm sure. How do I do that? While I had the pump off I did blow compressed air back from the inlet line.
 
   / 300 lawn runs 20 mins then backfires and dies
  • Thread Starter
#43  
Service manual says up to 14.7v. I put the old RR back in and that's what it read at full throttle, and around 9v at idle. Not sure maybe the issue before is it did not charge
 
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   / 300 lawn runs 20 mins then backfires and dies #44  
coloradotrout said:
My fuel pump was bad, but the filter could use a clean I'm sure. How do I do that? While I had the pump off I did blow compressed air back from the inlet line.
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Unfortunately blowing air back into the fuel tank will not remove any debris that may be clogging the strainer - it will just spread it all over the tank bottom.

The drain valve (shown in your post #18 year ago) will have to be removed for strainer cleaning.


I addition to cleaning up the strainer, I installed a generic inline fuel filter on mine little over two years ago. It was a little tight to make it fit and a little shorter filter next time will make it lot easier to install.

(The filter body is 1.75 inches long)

That's a cheap new carburetor from eBay vendor which has worked very well for over two years now.
The original carburetor had the throttle shaft worn way too loose and new OEM carburetor kit would have been around $300



IMG_4218.JPG Filter Body is 1.75 Inches Long.JPG
 
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