Why is the trimmer head smoking/melting?

In my experience you have major engine damage do to exhaust system blockage. One of a couple things happen the engine is blown, the exhaust system got so hot that is what melted the center console and the white smoke was plastic melting. But either way not good

Sounds like something is binding up, have you pulled it apart to make sure grass isn't underneath spool, or that spool spins freely after you refill line. Unless you are using replacement heads that are preloaded and they are generic and not fitting properly?

You will have to remove it by cutting all the line into. Sometimes you have to melt it with a hot blade to get it out

Hello,

Actually your exhaust, at the head, will glow red when the bike warms up - this is normal. Melting the plastic air filter case, however, is not.

The bike is obviously running way too lean if you were riding it during the 30 minutes you mentioned in your question. If it was sitting for 30 minutes, without air circulating around the engine, your exhaust would become extremely hot possibly melting the Air Filter Case. Check to make sure you air filter is clean and your carb(s) is/are set correctly. You should have an Idle Speed adjustment knob also - check your user manual to see if there is an idle speed RPM setting and set yours to it.

Another issue that might cause your problem is the use of improper oil in the crankcase. Again, check your user manual for the correct oil type that should be used. Some oils have additives that are not good for motorcycles and can ruin wet clutches and other engine parts.

Hope this gives you enough information to go on.

If you find this post helpful, please vote. Thank You.

Regards,

Oz

you can still use this heater, but continue to monitor its operation. If it gets hot enough to start smoking again, discontinue use and purchase a new one. Your safety means EVERYTHING!!!!!!

any electrical unit that smokes,is ,not worth repairing

The plastic head is overheating and melting because it is not fit for the work it is doing. When it cools the plastic hardens and it works until it heats again. You need a new head. Stephen.

wrong fuel/oil mixture...try 25mls of oil per litre fuel.