Spark arrestor clean-out plug question...

[gogators]

On my '05 Itasca (gas) and Onan 5500 genset, the maintenance manual says to remove the spark arrestor then start the gen and run at full load for 5 minutes to blow out soot. The gen set has about 300 run-hours. Problem: the plug has apparently never been removed and is very, very hard to turn. And, there is rust showing on the muffler around the plug. I can probably remove the plug but I'm afraid, in so doing, that I might damage the muffler. Questions: how important is it to periodically remove this plug to remove soot? Won't the soot be blown out the tailpipe when the set is running? Do you perform this maintenance on your genset? Any thoughts?

Larry

[Doug Sage]

I have never been able to get mine out either.. I have just ignored it.

[Dunnpe]

I took mine out last spring, after I sprayed a little penetrating oil on it and let it work while I changed the generator oil and filter. Plug came out easy and for what its worth very little rust was blown out through the hole. I have 500 hrs on the generator.

[Lt46]

Trying to be diligent in my preventive maint. I too tried to remove that blasted plug. Soaking it with PB blaster, using the proper socket and breaker bar only managed to tear the metal of the muffler itself. Mine is a 1997 model yr. and do not believe it had ever been removed. After replacing the muffler I've vowed to disregard this maint. suggestion.

[Hikerdogs]

I've taken ours out a couple times. The key is to run the generator about 5 minutes to warm the muffler. When it cools down to the point that you can touch it (it's still pretty hot) spray some PB Blaster on the plug and surrounding area. Let it set a few minutes then put an 8 point socket on the plug to remove it.

I would not use the standard 12 point socket because the contact area is so small the soft plug will almost certainly get rounded off.

Once the plug is out and the generator has been run for the proper amount of time put some hi temp anti sieze on the threads before reinstalling it. Also a word for the wise, don't run the generator with the plug removed over a grassy area. The heat will kill the grass