ATC70 110cc swap is way too loud!

[Quinc]

Must be getting old! I mostly ride around the neighbor with the kids and practice doing wheelies in front of the house. But now it is way to loud. Engine:
sikk 107ES (cleaned casting marks for the intake and opened it up to match the 22mm header. Also polished the exhaust port and opened it up to match the fmf header pipe.
22mm chinese carb
fmf exhaust
stock sprockets

She rips! No longer have to throw my weight back to get the front wheel up. However, she is way to loud. Sounds like my z400.. Anyone run the stock 70 exhaust on a 110 any tips on opening it up to let the 110 breath while keeping it quiet? Or is there a quiet crf50/110 exhaust out there that wont break the bank?

[barnett468]

In general, the quieter you make it, the less hp it will have.

I for one don't know of any super whazoo mufflers that will make it much quieter without costing much hp, and my first thought would be to look on ebay for a stock muffler off a slightly bigger bike like maybe a 125m or 200x or something and try that if it will fit without a lot of modding.
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[Quinc]

In general, the quieter you make it, the less hp it will have.

I for one don't know of any super whazoo mufflers that will make it much quieter without costing much hp, and my first thought would be to look on ebay for a stock muffler off a slightly bigger bike like maybe a 125m or 200x or something and try that if it will fit without a lot of modding.
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Good thinking! Wonder if a crf110 exhaust will fit ok or if it is too long.

[HorseMcHorseman]

Empty can of sea foam full of metal screen, cut another hole in the bottom same size as the inlet. Works great on my ds80

Edit: got home, took pictures

Attachment 258156
Attachment 258155

[barnett468]

Good thinking! Wonder if a crf110 exhaust will fit ok or if it is too long.

That won't quiet it nearly as much as a 200x one will, so i wouldn't want to pay more than $20.00 for a crf one if i was going to experiment with it. Also, if your bike is currently properly jetted and you put a 200x type silencer on it, you will likely have to go down on the main at least 1 size and possibly drop the needle 1 clip to get the jetting close.

here's a 200x one.



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[Quinc]

As a test I tried to put my atc70 oem exhaust back on, but it wont fit with the electric starter. Going to try adding some baffles/sing drain and new packing to my fmf. Might also try using a 45 degree silicone hose as a db snorkel to point the exhaust down.

[3 Wheel Drive]

Get a nice pair of ear muffs, duh!

[Quinc]

I don't have any issues with the noise! But the neighbors sure do.. lol Repacked and adding the sink strainer as a baffle helped. It is probably half as loud as what it was. (old packing was pretty burned up) I will probably add some more baffles and see how much it helps.