Onan SuperLoud 4000 - reduce exhaust smell
I have Onan microquite 4000 (actually SuperLoud 4000 model). It has about 1500 hrs (the RV is 11 years old). This weekend, while camping at Crystal Cove, the weather was hot so we had the generator ru...
Forum Discussion
WRT the noise, a lot of 'loud vs quiet' is in how good a job the RV makers do in installing it. If it's bolted directly to the frame in a bard metal compartment with a too-big ventilation opening in the door, and the outer end of the tailpipe tied down solidly so it can't shake? Yep, gonna be loud.
You need to get the Onan _installation_ manual for your model, and see what you can do to improve it. It details the required clearances and openings. Odds are that you can make improvements, maybe significant ones.
You probably should add the Onan resonator to the tailpipe; doesn't do much for quieting, but does smooth out the noise and lower the tone. Be sure the tailpipe is supported, but free to shake. Too-rigid mounting of that can prevent the built-in vibration isolation from working, since it's solidly tied to the engine.
But first you should probably also check the condition of the internal muffler at that many hours. Pull the generator so you can get the green top off of the box, and inspect the connection to the cylinder head and the rest of the muffler for cracks & other issues. Br sure the muffler-to-tailpipe joint is tight.
As far as odor, yes, check the air cleaner and the spark arrestor, and catch up any other maintenance issues. Also check the altitude adjustment. It is normal for the smell to be a bit worse at first, since it's running rich when cold, with the choke plate gradually opening as it warms up. You want to be sure that's actually operating properly.
Jim, "Mo' coffee!"
You need to get the Onan _installation_ manual for your model, and see what you can do to improve it. It details the required clearances and openings. Odds are that you can make improvements, maybe significant ones.
You probably should add the Onan resonator to the tailpipe; doesn't do much for quieting, but does smooth out the noise and lower the tone. Be sure the tailpipe is supported, but free to shake. Too-rigid mounting of that can prevent the built-in vibration isolation from working, since it's solidly tied to the engine.
But first you should probably also check the condition of the internal muffler at that many hours. Pull the generator so you can get the green top off of the box, and inspect the connection to the cylinder head and the rest of the muffler for cracks & other issues. Br sure the muffler-to-tailpipe joint is tight.
As far as odor, yes, check the air cleaner and the spark arrestor, and catch up any other maintenance issues. Also check the altitude adjustment. It is normal for the smell to be a bit worse at first, since it's running rich when cold, with the choke plate gradually opening as it warms up. You want to be sure that's actually operating properly.
Jim, "Mo' coffee!"
