Expansion Chamber Exhaust
- Thread starter jhendrix
- Start date
gothicguy64
Member
- Local time
- 10:48 PM
- Joined
- Aug 3, 2009
- Messages
- 231
hi
think of it this way the stock pipe works but do racing 2 stroke bikes use stock .
NO
depending on ur motor size u have to cut a small copper tube to fine tune and its dead easy to fit .
my motor is only a 48cc but it is fully worked an now i have a heep of sbp bits .
motor= rse hp1 but made to hp2.5 specs
sbp = shiftkit, exhaust , low profile filter, metal throttle , rocker kill switch , hix
plug , 2 inch front mount and a wider sealed bottom bracket .
when i got my bike it went 65 kph after 600 km i am now hoping on going even faster but i now need fuel line ,jb weld,plus a saw to cut tube to tune
exhaust.
ohh i forgot these motors are all orig russian m21,s (2 strokes) but good luck finding a m21 ,one went on sale 4 yrs ago and sold for more than 1000.
brad
syd
think of it this way the stock pipe works but do racing 2 stroke bikes use stock .
NO
depending on ur motor size u have to cut a small copper tube to fine tune and its dead easy to fit .
my motor is only a 48cc but it is fully worked an now i have a heep of sbp bits .
motor= rse hp1 but made to hp2.5 specs
sbp = shiftkit, exhaust , low profile filter, metal throttle , rocker kill switch , hix
plug , 2 inch front mount and a wider sealed bottom bracket .
when i got my bike it went 65 kph after 600 km i am now hoping on going even faster but i now need fuel line ,jb weld,plus a saw to cut tube to tune
exhaust.
ohh i forgot these motors are all orig russian m21,s (2 strokes) but good luck finding a m21 ,one went on sale 4 yrs ago and sold for more than 1000.
brad
syd
retromike3
Member
- Local time
- 6:48 AM
- Joined
- Nov 23, 2008
- Messages
- 409
I really like S.B.P. tuned pipe
When I put the pipe on my old motor It was like a adding a supercharger. My bike could now go up the same hills I used have to pedal without having to pedal at all. It made a major difference right away. Nothing else I have done has made such a dramatic change in the performance.
I did note that my gas milage did go down a bit but the increase in power makes up for that loss.
It did take me a while to get it "tuned" correctly. I started by cutting a very small part of the copper pipe that connects the block to the first part of the pipe in order to get the power band right were I wanted it,so I never took more than a sixteenth of a inch off at a time.
One of the effects of the pipe is that the power band is a much smaller area than the stock pipe, but with that much more" bang" its worth the sacrifice.
I broke a motor mount on my old engine so when I went to reinstall my pipe I had to replace the copper tube that went from the block to the first part of the pipe because it had melted. It cost me a grand total of two dollars and thirty cents to replace it. More expensive than that was the new set of heat resistant tubing (about ten bucks) but as far as I am concerned the total price of that pipe is worth its wait in gold.
mike
When I put the pipe on my old motor It was like a adding a supercharger. My bike could now go up the same hills I used have to pedal without having to pedal at all. It made a major difference right away. Nothing else I have done has made such a dramatic change in the performance.
I did note that my gas milage did go down a bit but the increase in power makes up for that loss.
It did take me a while to get it "tuned" correctly. I started by cutting a very small part of the copper pipe that connects the block to the first part of the pipe in order to get the power band right were I wanted it,so I never took more than a sixteenth of a inch off at a time.
One of the effects of the pipe is that the power band is a much smaller area than the stock pipe, but with that much more" bang" its worth the sacrifice.
I broke a motor mount on my old engine so when I went to reinstall my pipe I had to replace the copper tube that went from the block to the first part of the pipe because it had melted. It cost me a grand total of two dollars and thirty cents to replace it. More expensive than that was the new set of heat resistant tubing (about ten bucks) but as far as I am concerned the total price of that pipe is worth its wait in gold.
mike
Last edited:
gothicguy64
Member
- Local time
- 10:48 PM
- Joined
- Aug 3, 2009
- Messages
- 231
hey mike what size motor u using and how much u cut off ur tube to tune it ?
brad
brad
gothicguy64
Member
- Local time
- 10:48 PM
- Joined
- Aug 3, 2009
- Messages
- 231
ok its time u went to sick bike parts and asked the pros .
brad
brad
