Tuesday, December 15, 2015

Honda 2000i Generator Exhaust Extension

During heavy storms when the power goes out, I wanted a way to keep the generator running inside a garage (with the door open about a foot and yes I have a carbon monoxide detector in the garage and in the house) or in a tool shed so not to have the generator running unprotected outside getting wet during rain/snow from the storm when the generator power is most likely needed. I didn’t want a complicated permanently attached exhaust pipe. I wanted to maintain the generators portability because I use it for power tools including my new WORX electric chainsaw.

This is what I came up with, a simple exhaust extension using simple hand tools, hardware store pipe components and a little help of a welder friend.

Materials used in exploded view:
  • 5 feet of 1¼in ID Flexible Stainless Steel Exhaust pipe. (What's not shown is a 12-foot long exhaust pipe that couples to the flex pipe to get the exhaust even further from the garage).
  •  http://www.summitracing.com/parts/wlk-40001
  • ¾ in npt x 4 in nipple
  • ¾ in npt pipe coupler.
  • ¾ in npt x 2 in long pipe nipple.



Assembled components. I’m waiting for my mail ordered 1¼ dia muffler clamp to secure the flex pipe to the nipple.



Generator before exhaust modification.


Rear grill removed showing the muffler.



Holding the short nipple onto exhaust port to show you how/where the short nipple will be welded on.



Muffler removed, just three bolts.



Close up of the muffler exhaust port.



Close up of exhaust port with nipple ready to be welded onto the exhaust port. 
In the photo it appears I cut off some of the threads of the nipple. I didn't, what I did do was grind the threads on one end so the nipple metal was thinned down to about 1/32 inch thick. This was so the sheet metal of the muffler and the end of the nipple were about the same thickness. This lesson the chance of too much welder amps needed to melt the nipple and not burn holes in the muffler steel.


New welded exhaust nipple through grill.


The flex pipe adapter nipple and coupler that thread onto the welded nipple.


Flex pipe installed.


Flex pipe installed and on the ground. 5 feet of flex pipe used. ( not shown is another 12-foot long exhaust pipe)




19 comments:

  1. Mike that looks great. It is now indoor safe. A Honda is ultra quiet running with little exhaust noise. I saw neat secondary muffler made from a tomato juice can with holes drilled in it that was stuck on the end of a flex pipe. It cost nothing and acted like a silencer.

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    Replies
    1. No Gas engine used indoors is safe. This set up is OK but I have to be careful of wind gusts pushing the exhaust fumes back into the garage and then house. This is why I have two detectors, one in the garage and the other inside the house.

      There are many ways of quieting noisy exhaust with home built suppressors. The second biggest place generator noise comes from is the carburetor intake! Next time yours is running gently hold a wadded up bathe towel in front of the air intake. It will amaze you at how quiet the engine will become.

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  2. 1.25 inch flex tubing is too large to fit snugly over 0.75 inch pipe. 1 inch tubing would be a better choice. Please amend your post.

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  3. Anon 1-25-2017
    Thank you for you comment, it tells me readers do pay attention! The problem with using standard inch sizes/vs pipe sizes is most people do not understand the actual size vs industry pipe standards. My descriptions of pipe actual dimensional sizes are correct.

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  5. did you cut one set of threads off the short nipple

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    Replies
    1. Sorry for the delay answering your question. Busy here.
      In the photo it appears I cut off some of the threads of the nipple. I didn't, what I did do was grind the threads on one end so the nipple metal was thinned down to about 1/32 inch thick. This was so the sheet metal of the muffler and the end of the nipple were about the same thickness. This lesson the chance of too much welder amps needed to melt the nipple and not burn holes in the muffler steel.

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    2. Thanks for all of this Mike. I am new to welding and am aware of incompatible thickness from the coupler and actual muffler and welding amps. I would try it myself if new mufflers weren't so expensive in case I screw it up. I am going to take my project into a welding shop. Maybe buy brass so they can braze it. Wish the old farmer would have taught a bit more of this to his farm girl before he passed last year.

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  6. Why dont Honda just make the exhaust long enough for the extensions use. I have no way of welding anything onto my unit. Would cost a lot to have it done.

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    Replies
    1. Who knows what their thinking is!

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    2. It cheap just take muffler off and take it to a welder

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    3. Don,
      I did remove the muffler to make it easy to weld. I think it was only $20.00 for the welding and that was having the welder come by my house.

      Delete
  7. Have you had any issues with overheating with the extension in place?

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  8. Have you had any issues with overheating with the extension in place?

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  9. Replies
    1. I had the same question. I would guess that in Honda's design, they would have to take the extension into consideration of the overall build. Perhaps a 30' extension(sounds crazy but someone would do it) may affect performance.

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