Cheap expansion chamber

sonic883

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Hi, I have a 80cc 2 stroke, everything is stock except for chain. It’s running decent, but I kinda feel bad for it, I need to upgrade to higher performance parts. I am first thinking expansion chamber, but I’m aware that some expansion chambers are junk. Can someone suggest me a really good expansion chamber, for a relatively cheap price. Price range (50 to 100 $) it doesn’t have to be a expansion chamber but I’m leaning towards it, just need a first good upgrade to increase performance. (Located in aus)
 

YetiWoodz

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First, get a jet kit so you can swap out the jet in the carb so it runs better. Easiest power gain and the spark plug won't keep fouling. Change your rear sprocket to a smaller one if you want more top speed at expense of hill climbing power.

Best way with expansion chambers is to learn how to weld (doesn't take too long for this purpose) and buy a pipe and modify it to fit on your bike. You can pick up a flux core welder anywhere from $90 and up.
 

Jayraye39

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Hi, I have a 80cc 2 stroke, everything is stock except for chain. It’s running decent, but I kinda feel bad for it, I need to upgrade to higher performance parts. I am first thinking expansion chamber, but I’m aware that some expansion chambers are junk. Can someone suggest me a really good expansion chamber, for a relatively cheap price. Price range (50 to 100 $) it doesn’t have to be a expansion chamber but I’m leaning towards it, just need a first good upgrade to increase performance. (Located in aus)
EBAY search Nasty Jack exhaust for 66cc. They are a very very close replica to the MZ65 pipe. The welds look ugly but dont leak and fitment is good. Will give you twice the power you have now. $59. I bought one, cut it up to fit my bike and rrwelded it. My bike has never been faster. Chorse i do have many mods.Porting, Port matching, and pistin crown ramps on transfers are your best mods for this pipe. You will fly
 

Wevil Knievel

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Personally I like the flexable exhaust pipe. It has an expansion and Muffler chamber built in and it's flexible enough that you can use it on many different builds I have put mine on probably five different bicycles already and it still works like a champ. And it sounds good and it gives you good Power Band.
 

Whitewill1412

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get an mz65 clone, they are like 50 or 60 bucks. work great on stock motors. it's a bolt on part, you will have to rejet the engine for the new flow though.
When you add an expansion chamber do you need to up the jet size? What is the usual jet size needed?
 

Jayraye39

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When you add an expansion chamber do you need to up the jet size? What is the usual jet size needed?
Depends. diff on each setup. I had an ht speed carb no filter and ran a 69jet. Got an expansion chamber and velocity stack and used the new bofeng carb and it ran perfect. I believe the jet in a bofeng is a 70. So yes i went up a jet size on pipe and stack
 

Redneckcruisersoftexas

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Personally I like the flexable exhaust pipe. It has an expansion and Muffler chamber built in and it's flexible enough that you can use it on many different builds I have put mine on probably five different bicycles already and it still works like a champ. And it sounds good and it gives you good Power Band.
I have the same pipe and have noticed a power loss so I am going to cut the muffler off
 
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