Small Engines (Lawn Mowers, etc.): Tanaca Blower losing power, carb settings, leaf season

Question
Hi John,

I have a tanaka TBL-505 backpack blower. It has had an issue for quite some time (a few years) that I have been able to work with but now I have larger property and it is becoming annoying. The blower runs great for about 20 minutes at full throttle. It then starts to lose power and will stall out. If i throttle it back to an idle it will continue running. If I let it idle for a minute or so, I can then run it a full throttle for about 5 minutes before it starts to die out again.

If i turn it off and let it sit for a few minutes, when i use it again it will run great again for the 20 minutes and the cycle starts over.

I removed the air filter to rule that out, but that was not the issue.

The blower and my line trimmer use the same gas, so I am fairly sure that the gas is OK. The plug has been cleaned as well as replaced since this issue has started.

I have not touched the carb setting because I have not had good luck touching the carb settings  in the past, and I am in the middle of leaf season.

Thanks for any help you can provide.

Answer
Hello John:

From your Description it Sounds like the Coil/Ign Module is Heating up and the Plug Stops Firing. The Following is an Instruction File I Made for Checking and Repairing this Problem. Run the Engine Until it Quits (Do Not Try to Keep it Running. Run at High Speed Until it Stops on it's Own), then Remove the Spark Plug. Wrap a Wire Around the Threads and Attach the Other End of the Wire to the Engine Block Turn the Engine and See if the Plug Fires. If No, then Disconnect the Shut Off Wire at the Control Bracket First (if it has one), Check for Fire at the Plug. If Still No Fire at the Plug; Then Disconnect the Shut Off Wire at the Coil (usually requires removal of the blower housing) and Check for Fire at the Plug. If No Fire at the Plug , then the Coil/Ign Module is Bad. The Coil/Ign Module to Flywheel Gap is .020in. If there is Fire, then the Rings are Most Likely Stuck or Worn Out and the Block is Expanding Past the Point the Rings can Expand and you Slowly Lose Compression. Please, Do Not Hesitate, If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John