Penton Owners Group

General Discussion => Penton Talk => Topic started by: skiracer on November 12, 2020, 05:15:32 PM

Title: Generator mufflers....
Post by: skiracer on November 12, 2020, 05:15:32 PM
If I added an additional muffler to a generator, would that create any adverse effects to the motor from the additional back pressure?  Looking to have less noise output from one.  Thoughts, ideas?

1976 250 MC5 Original Owner
1976 Penton 175 XC
Title: Generator mufflers....
Post by: Dale Sonnenschein on November 13, 2020, 11:45:34 AM
I saw one with a bike exhaust from a 4 stroke at one of the races. Couldn't hear it running. Not sure if it has any affect on it, but it ran for quite awhile.
Title: Generator mufflers....
Post by: skiracer on November 13, 2020, 07:21:30 PM

Thanks Dale!

Quotequote:Originally posted by Dale Sonnenschein

I saw one with a bike exhaust from a 4 stroke at one of the races. Couldn't hear it running. Not sure if it has any affect on it, but it ran for quite awhile.

1976 250 MC5 Original Owner
1976 Penton 175 XC
Title: Generator mufflers....
Post by: firstturn on November 15, 2020, 05:24:12 PM
The  first problem is the Onan runs all the time at operating RPMs and that is why there is so much noise to contend with on a normal running cycle.  Unlike the Honda that only runs the amount of RPMs needed by demand of power needed.
  The simplest way to get some noise reduction is to insulate the area around the box where the generator is located.  Remember you have to have enough area to have air for the generator to operate.  Here is a simple UTUBE that dropped the noise level by 5 decibels.  Adding another muffler doesn't seem to help since most of the noise isn't the exhaust, but egine operating noise. Hope this helps.
https://www.classbforum.com/forums/f5/making-an-onan-quiet-generator-quieter-9229.html

Ron Carbaugh
Title: Generator mufflers....
Post by: skiracer on November 15, 2020, 05:31:44 PM
Hey Ron, thanks for the info. Really good points. The generator is contained in its own box so adding to the exterior of it should not be too hard to do. Just have to be mindful around the intake and the exhaust. (Lesson learned from reading about Tom Penton's idea of sound reducing....)

Quotequote:Originally posted by firstturn

The  first problem is the Onan runs all the time at operating RPMs and that is why there is so much noise to contend with on a normal running cycle.  Unlike the Honda that only runs the amount of RPMs needed by demand of power needed.
  The simplest way to get some noise reduction is to insulate the area around the box where the generator is located.  Remember you have to have enough area to have air for the generator to operate.  Here is a simple UTUBE that dropped the noise level by 5 decibels.  Adding another muffler doesn't seem to help since most of the noise isn't the exhaust, but egine operating noise. Hope this helps.
https://www.classbforum.com/forums/f5/making-an-onan-quiet-generator-quieter-9229.html

Ron Carbaugh


1976 250 MC5 Original Owner
1976 Penton 175 XC
Title: Generator mufflers....
Post by: firstturn on November 16, 2020, 08:41:03 PM
Watch the utube and this guy did the insulation inside the box.

Ron Carbaugh
Title: Generator mufflers....
Post by: skiracer on November 18, 2020, 08:05:55 AM
Hey Ron,
Thanks for the link.  Sounds like the right method to use.  I have some ordered, will let you know how it works out.  Hope you and your family have a great Thanksgiving!  Jl

Quotequote:Originally posted by firstturn

The  first problem is the Onan runs all the time at operating RPMs and that is why there is so much noise to contend with on a normal running cycle.  Unlike the Honda that only runs the amount of RPMs needed by demand of power needed.
  The simplest way to get some noise reduction is to insulate the area around the box where the generator is located.  Remember you have to have enough area to have air for the generator to operate.  Here is a simple UTUBE that dropped the noise level by 5 decibels.  Adding another muffler doesn't seem to help since most of the noise isn't the exhaust, but egine operating noise. Hope this helps.
https://www.classbforum.com/forums/f5/making-an-onan-quiet-generator-quieter-9229.html

Ron Carbaugh


1976 250 MC5 Original Owner
1976 Penton 175 XC