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Old 10-14-2016, 10:26 PM   #1
Senior Member
bigben's Avatar
Brand: Thor Motor Coach
Model: Challenger 37TB
State: Kentucky
Posts: 1,026
THOR #1020
Changing Plugs in Onan RV QG 5500

We spend a great deal of time dry camping. I have always performed oil changes and air filter changes myself. Our onboard Onan RV QG 5500 started "sputtering" when under full load. I've used SeaFoam to clean the generator intake and it has helped. But the last few uses, the unevenness of the idle has not cleared up. With 650+ hours on the generator, I decided to changes the spark plugs (I found out the manual recommends changing at 500 hours).

I looked all through the internet with little success on information. Not much around. Just finding the location of the plugs was purely by feel as seeing the plugs isn't possible in our coach.

I did read inputs from others on tools and approach. So I decided to document with pics the where the plugs are at and tools I used.

Once you find the plugs by feel, changing them took me about 20 mins. Plug #2 (as shown in the attached PDF) is the toughest one - simply because of limited access. Also note that following the suggesting of others, I removed the rubber rings from the plug wrench.

Hope this helps.
Attached Files
File Type: pdf Onan5500PlugChange1.pdf (262.3 KB, 317 views)

US Army Retired - Loving The Road Trip
Challenger 37TB
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Old 10-14-2016, 10:40 PM   #2
Senior Member
Oneilkeys's Avatar
Brand: Thor Motor Coach
Model: 2016 Axis 24.1
State: Florida
Posts: 2,259
THOR #1765
Great info. Thanks for sharing....
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