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Rich Biebel · 09-15-2019, 12:45 PM

The belt arrangement has not changed much on the 10's and 12's for years. The radiator was always down below the generator barrel end. They use an engine driven fan arrangement to move the air inside the machine....Draws air up and in across the radiator and blows hot air out the other end and below....

The newer machines for some reason have had belts fail prematurely

The older machines did not have the failures for many hours and had the same basic design. The fan arrangement was changed a little but still similar....

7.5 diesels also lose W/P belts but usually from age....many years old no matter how many hours...

The hot air exhaust end of the machine needs to have the proper opening in the compartment....and the air needs to be prevented from being blown into the generator compartment.

I recently installed a replacement 12.5 and had to fabricate a piece of metal to block that hot air from just getting blown inside the compartment.....I also cut the floor of the box out more to better allow the hot air to escape....The machine I replaced had 10,000 and had issues at races down south when it was very hot....possibly the added heat getting in the compartment causing trouble...

I changed a belt on a 10 not to long ago...in a food truck and it was changed once before not long after it was new.

One of the medical buses has had at least 2 belts and the other one has had none done. One machine has at least 5000hrs and the other probably 3000

09-15-2019, 12:45 PM	#29
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,275 Likes: 25 Liked 510 Times in 200 Posts	Re: ONAN Marquis Gold 7000 Gas The belt arrangement has not changed much on the 10's and 12's for years. The radiator was always down below the generator barrel end. They use an engine driven fan arrangement to move the air inside the machine....Draws air up and in across the radiator and blows hot air out the other end and below.... The newer machines for some reason have had belts fail prematurely The older machines did not have the failures for many hours and had the same basic design. The fan arrangement was changed a little but still similar.... 7.5 diesels also lose W/P belts but usually from age....many years old no matter how many hours... The hot air exhaust end of the machine needs to have the proper opening in the compartment....and the air needs to be prevented from being blown into the generator compartment. I recently installed a replacement 12.5 and had to fabricate a piece of metal to block that hot air from just getting blown inside the compartment.....I also cut the floor of the box out more to better allow the hot air to escape....The machine I replaced had 10,000 and had issues at races down south when it was very hot....possibly the added heat getting in the compartment causing trouble... I changed a belt on a 10 not to long ago...in a food truck and it was changed once before not long after it was new. One of the medical buses has had at least 2 belts and the other one has had none done. One machine has at least 5000hrs and the other probably 3000 __________________ Rich Biebel S/C 1479 Last edited by Rich Biebel; 09-15-2019 at 12:51 PM.