Weedeater operating speed

Old 06-16-12, 09:39 AM
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Weedeater operating speed

My husband told me when operating my cheap $65 weedeater that I had to run it "wide open" or it will ruin the spark plug. I did this and the whole end of the weed eater overheated and fell off. Apparently this was the wrong advice. What is the right answer?
Old 06-16-12, 01:17 PM
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IMHO, run it as slow as you can and still cut the weeds, it will be necessary if equipped with a bump feed to rev it up to get the line to feed when you bump it. Also for a cheap trimmer I recommend making the fuel mixture a little richer, instead of 40:1 or 50:1 I would suggest 32:1, lowend trimmers lack any steel lining in the cylinder so more lubrication helps, if they run too lean they will score/scratch the cylinder walls which equals instant junk. Have a good one. Geo
Old 06-16-12, 07:59 PM
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Most of the time, the recommendation is to run a 2-stroke engine full throttle because running it too slowly will contribute to carbon buildup in the exhaust port, piston rings, muffler, and the spark plug. It can ruin an engine. This is probably what he is going on. The end falling off is not because of running it wide open, but because of it being $65.
Old 06-17-12, 06:47 AM
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Yep, a two stroke isn't much of a lugger. No rpms = no power to do anything. Most of them have a short rpm range power band. 4 strokes are a lot different in that respect, but 4 stroke weed wackers still have to be ran FT to get the job done.

The thing with your weed eater is to have the carb set properly. In that the full throttle setting should be slightly short of max rpms. You go to the high speed screw on the carburetor, turn it in for max rpms with the throttle wide open, then back slightly to cut the rpms - usually about 1/16 of a turn will do it. This will give you a little more lubrication and cooler running. You'll have just a tiny bit of smoke at this setting but not much.

To run the leanest mixture would give you more rpms, but the power would trail off at the rpm peak and damage risk to the engine would go up significantly.

For the end heating up and falling off, have your husband drill a small 1/32 hole in the main tubing that leads to the cutting head and squirt some lubricant like Teflon or graphite down it once a week or so. That will keep the core lubed up. Use a piece of electricians tape to cover the hole or make a plug to fit it.

So, since this is Father's day, go tell your husband he was right................... again

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