My bike has the common Huasheng 142F 49cc 4-stroke. I recently replaced the "kit" exhaust that came with the engine. I'm now using a 7/8" ID stainless steel flex pipe purchased from Memory Lane Classics <http://www.memorylane-classics.com/>.
I've read on this forum that dynamometer testing by EZ Motorbike showed that replacing the kit exhaust with the flex pipe has been shown to give an 18% increase in horsepower.
I installed the flex pipe by hacksawing the old exhaust's primary pipe about two inches from the engine, sliding the flex pipe over the remaining nub, and securing the pipe with a hose clamp. I then secured the lower end of the pipe with a special clamp (also purchased from Memory Lane Classics) to the bottom of my EZM Q-Matic transmission, and attached the end tip that came with the flex pipe.
I fired up the bike, and I was immediately VERY pleased with the deep, gutsy new sound of the Huasheng as it breathed much more freely. Others on this forum have said that it's a sound somewhat like a Harley, and I have to agree! Especially when the bike is first started and is warming up.
On my first test run with the new exhaust, I was VERY pleased with the gain in horsepower that I experienced. I fully believe that EZM figure of an 18% horsepower gain! The HP gain is very noticeable when starting from a dead stop at a stop sign or stoplight, or when climbing any grade. And the top end for my bike on flats (as revealed by my wireless speedometer) has increased from 31 MPH to 35 MPH. The confidence in traffic that I get from faster-off-the-line starts is a real benefit -- and I look a lot cooler now that I can get up to speed quicker!
But...this new exhaust is loud. Not terribly loud, but a bit louder than I'm comfortable with. I've seen little kids plugging their ears as I've approached! And, on longer rides (my commute to work, for example), I've used foam ear plugs.
So I sought out a way to muffle the exhaust somewhat, and the solution was quite simple and inexpensive. I found that a very standard "cigar-type" muffler for small engines is a universal fit (Briggs & Stratton, Tecumseh, Kohler) muffler with a 3/4" male coarse thread. These can be bought from a variety of manufacturers, quite inexpensively. I bought my "Arnold" brand muffler at my local True Value store for about $6.00.
To attach the muffler to the flex pipe, I found the ideal fitting in True Value's plumbing department. It's the "3/4-inch FPT street adapter" (pictured below). It's copper, and it costs about $8.00. I had to ream the opening in the end of the flex pipe a bit to slide this adapter into it; a pair of closed pliers, pushed into the pipe opening and rotated, works well. It's a tight fit to get the adapter attached, but once it's hose-clamped, it's not going anywhere...ever! The muffler then simply screws into the adapter. So, if for some reason I want to run the bike without the muffler (or if I need to attach a new muffler), it's a simple matter of unscrewing/rescrewing the muffler to the adapter.
I was somewhat concerned about changing the flow characteristics of my flex pipe exhaust by attaching a muffler. But the muffler is VERY non-restrictive, and the final result has been: no noticeable decrease in horsepower, and an ideal decibel-reduction in the sound of the exhaust. My bike is a bit quieter, but it still has a deep, throaty sound to it.
If you're running a Huasheng 49cc engine, I highly recommend this exhaust system.
Cheers,
Max-M
I've read on this forum that dynamometer testing by EZ Motorbike showed that replacing the kit exhaust with the flex pipe has been shown to give an 18% increase in horsepower.
I installed the flex pipe by hacksawing the old exhaust's primary pipe about two inches from the engine, sliding the flex pipe over the remaining nub, and securing the pipe with a hose clamp. I then secured the lower end of the pipe with a special clamp (also purchased from Memory Lane Classics) to the bottom of my EZM Q-Matic transmission, and attached the end tip that came with the flex pipe.
I fired up the bike, and I was immediately VERY pleased with the deep, gutsy new sound of the Huasheng as it breathed much more freely. Others on this forum have said that it's a sound somewhat like a Harley, and I have to agree! Especially when the bike is first started and is warming up.
On my first test run with the new exhaust, I was VERY pleased with the gain in horsepower that I experienced. I fully believe that EZM figure of an 18% horsepower gain! The HP gain is very noticeable when starting from a dead stop at a stop sign or stoplight, or when climbing any grade. And the top end for my bike on flats (as revealed by my wireless speedometer) has increased from 31 MPH to 35 MPH. The confidence in traffic that I get from faster-off-the-line starts is a real benefit -- and I look a lot cooler now that I can get up to speed quicker!
But...this new exhaust is loud. Not terribly loud, but a bit louder than I'm comfortable with. I've seen little kids plugging their ears as I've approached! And, on longer rides (my commute to work, for example), I've used foam ear plugs.
So I sought out a way to muffle the exhaust somewhat, and the solution was quite simple and inexpensive. I found that a very standard "cigar-type" muffler for small engines is a universal fit (Briggs & Stratton, Tecumseh, Kohler) muffler with a 3/4" male coarse thread. These can be bought from a variety of manufacturers, quite inexpensively. I bought my "Arnold" brand muffler at my local True Value store for about $6.00.
To attach the muffler to the flex pipe, I found the ideal fitting in True Value's plumbing department. It's the "3/4-inch FPT street adapter" (pictured below). It's copper, and it costs about $8.00. I had to ream the opening in the end of the flex pipe a bit to slide this adapter into it; a pair of closed pliers, pushed into the pipe opening and rotated, works well. It's a tight fit to get the adapter attached, but once it's hose-clamped, it's not going anywhere...ever! The muffler then simply screws into the adapter. So, if for some reason I want to run the bike without the muffler (or if I need to attach a new muffler), it's a simple matter of unscrewing/rescrewing the muffler to the adapter.
I was somewhat concerned about changing the flow characteristics of my flex pipe exhaust by attaching a muffler. But the muffler is VERY non-restrictive, and the final result has been: no noticeable decrease in horsepower, and an ideal decibel-reduction in the sound of the exhaust. My bike is a bit quieter, but it still has a deep, throaty sound to it.
If you're running a Huasheng 49cc engine, I highly recommend this exhaust system.
Cheers,
Max-M