Husqvarna 128LD Weedeater

[DavidD]

I was having a problem with the weedeater bogging down and then cutting off. Just like it was starving for fuel. Removed the carb, cleaned and reinstalled. I replaced the fuel lines and filter also. Still had the same problem. Checked compression per other post and had good compression (90 to 110 - I had 120PSI). Removed the spark arrestor on the muffler to check the screen - good. Finally it died and would not restart. I checked the purge pump ball- had fuel. I removed the spark plug, reattach the spark plug wire and added a jumper wire connected to the spark plug to the body of the muffler and then pulled starter handle to check for spark at the plug - had none. I replaced the coil and restarted again - it started but had the same bogging down problem and cutting off. While I was installing the coil I checked the wiring harness from the coil to the On/Off switch for chafing - none found. Then I read a post about having the wrong spark plug in it (I replaced the spark plug with one I got from the hardware store (had to cross reference the plug number because they did not stock the brand that came out of it) last fall when I was servicing my lawn equipment for the last time for the winter. I purchased the NGK BPMR6A spark plug and took care of my problem. Some of the spark plugs apparently back feeds through the spark plug wire and causes the coil to stop functioning. That is why when I checked for spark I was using the plug that was causing the coil not to fire. This seems to be a common problem with this model. BOTTOM LINE - ONLY REPLACE SPARK PLUGS WITH EXACTLY THE OE SPARK PLUGS

 

[bertsmobile1]

The tiny circuit boards in some of the coils which have replaced to points actually use the resistance of the spark plug to do the timing with.
So on some, just going up or down a heat range can cause a missfire.
Been caught out like that a couple of times

 

[edgreeson65]

I was having a problem with the weedeater bogging down and then cutting off. Just like it was starving for fuel. Removed the carb, cleaned and reinstalled. I replaced the fuel lines and filter also. Still had the same problem. Checked compression per other post and had good compression (90 to 110 - I had 120PSI). Removed the spark arrestor on the muffler to check the screen - good. Finally it died and would not restart. I checked the purge pump ball- had fuel. I removed the spark plug, reattach the spark plug wire and added a jumper wire connected to the spark plug to the body of the muffler and then pulled starter handle to check for spark at the plug - had none. I replaced the coil and restarted again - it started but had the same bogging down problem and cutting off. While I was installing the coil I checked the wiring harness from the coil to the On/Off switch for chafing - none found. Then I read a post about having the wrong spark plug in it (I replaced the spark plug with one I got from the hardware store (had to cross reference the plug number because they did not stock the brand that came out of it) last fall when I was servicing my lawn equipment for the last time for the winter. I purchased the NGK BPMR6A spark plug and took care of my problem. Some of the spark plugs apparently back feeds through the spark plug wire and causes the coil to stop functioning. That is why when I checked for spark I was using the plug that was causing the coil not to fire. This seems to be a common problem with this model. BOTTOM LINE - ONLY REPLACE SPARK PLUGS WITH EXACTLY THE OE SPARK PLUGS

I had the exact same issue, had changed ignition module and carb with the problem not going away. I changed the spark plug to a NGK BPMR6A per your post and it runs great now - THANK YOU!!