muffler for 4 stoke engine

jimj

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Hi:
I have a 4 stroke 49cc HS engine. I saw an article about using a 2 cycle muffler on this engine giving it more power and better breathing as the engine has the square box muffler.
Will a muffler come with the necessary clamps, gasket etc. for installation or do I use the ones from the square muffler? I think the muffler gives it a better look too. I read also that a flexible pipe going under the engine is another option. Which is quieter and better sounding?

Thanks for any suggestions.
 
Some come with the gasket and some don't but you will need a gasket as the stock exhaust does not have a gasket. And, you will also need a muffler holder as you do not want the bolts to shear also probably good to get steel bolts replacements. The standard 2 stroke muffler will require you to install the extended pedals if it is not on there already as the muffler will interfere with normal pedals (atleast it did for me).

I am liking the design of the long racing header mufflers, which is suppose to give more middle and top end power. And, it looks like it snakes under the bike so no need to put the extended pedals on. This site is sold out but you get the idea...

http://www.affordablegokarts.com/mm...de=A&Product_Code=22110&Category_Code=MTRBK49

Video of guy with the muffler. that sound is it produces is louder but nice

 
Some come with the gasket and some don't but you will need a gasket as the stock exhaust does not have a gasket. And, you will also need a muffler holder as you do not want the bolts to shear also probably good to get steel bolts replacements. The standard 2 stroke muffler will require you to install the extended pedals if it is not on there already as the muffler will interfere with normal pedals (atleast it did for me).

I am liking the design of the long racing header mufflers, which is suppose to give more middle and top end power. And, it looks like it snakes under the bike so no need to put the extended pedals on. This site is sold out but you get the idea...

http://www.affordablegokarts.com/mm...de=A&Product_Code=22110&Category_Code=MTRBK49

Video of guy with the muffler. that sound is it produces is louder but nice

 
Bakaneko that is a cool sound for a muffler but pretty loud. I was looking at the 2 stroke muffler as it seems harder to find a 4 stroke muffler. I know some kits show a regular muffler than the square stock one. Don't know if its the 2 stroke, but to me a muffler is a muffler since I am not looking for a high performance out of the engine as I am too old for cruising around at full throttle. I will be using the SBP shift kit for this engine as my bike a Fito Modena GT2 has rear disk brake so adding a sprocket is probably too tight. KCVale has a more direct drive shifter but it is more expensive so I went with the SBP, and I like the extra rear bracket that connects to the engine mount that I think gives the mount more rigidity to keep things from moving around.Pedaling on a dead engine may be a big hassle though.
Getting back to the 2 stroke muffler. How do you connect the flange to the engine block, because I saw a muffler with only a flared end . There is also one with a 2 bolt flange which bolts to the engine. I suppose the bolt hole spacing is different between the 2 stroke vs. 4 stroke engines. I have to watch for the proper fitting muffler huh?
Thanks for your reply, much appreciated
 
I picked up a 4 stroke exhaust from boygoesfast on eBay, had to file some bumps down on the flange but other than that was in great condition. Sounds awesome and I believe the baffles inside are less restrictive than the exhaust that come with the bikeberry kit. Bolt pattern between the 2 stroke and 4 stroke are the same, only difference is the angle the pipe is welded to the flange.
 
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I picked up a 4 stroke exhaust from boygoesfast on eBay, had to file some bumps down on the flange but other than that was in great condition. Sounds awesome and I believe the baffles inside are less restrictive than the exhaust that come with the bikeberry kit. Bolt pattern between the 2 stroke and 4 stroke are the same, only difference is the angle the pipe is welded to the flange.
 
HI Dan; Hey thanks for the reply. I guess I will need the 4 stroke muffler as you mentioned the angle of the pipe is slightly different from the 2 stroke. I was looking more for a all black muffler but I guess I will have to settle for the chrome as I don't see a black one for the 4 stroke. Maybe I'll e-mail them and ask if there is a black one for the 4 stroke. Good to know that the bolt pattern is the same as I was wondering about that. What kind of gasket did you use for the mounting and did you buy bolts?

Good tread, thanks.
 
HI Dan; Hey thanks for the reply. I guess I will need the 4 stroke muffler as you mentioned the angle of the pipe is slightly different from the 2 stroke. I was looking more for a all black muffler but I guess I will have to settle for the chrome as I don't see a black one for the 4 stroke. Maybe I'll e-mail them and ask if there is a black one for the 4 stroke. Good to know that the bolt pattern is the same as I was wondering about that. What kind of gasket did you use for the mounting and did you buy bolts?

Good tread, thanks.
You could use the 2 stroke pipe and just bent it too fit
 
Yea, that might me the way for me to go as my bike is all flat black so a black muffler will blend in good.

Thanks
 
As jimj said you can use a 2 stroke exhaust, just gotta bend it some to fit. Pack the pipe with sand to prevent kinks. Not sure if you want to use a torch to heat up a black exhaust, but it'd be easier.

I'm searching for a 28.5" long, 7/8" inner diameter stainless flex tube. Then my current exhaust will be chopped down to a 4" nub and that flex tube clamped on. At that point it wouldn't matter if it was a 2 or 4 stroke exhaust.

You can also purchase heat resistant paints of virtually any color that would work on the exhaust.
Rust-oleum makes a heat resistant line good up to 1200F.
 
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