yes you need to have the exhuast system preasure but doesnt that take place in the straight pipe no the silencer, alll the silencer or slip on does is reduce noice and some have sparkys

 

The slip on reduces the flow, therefore it reduces the negative pressure you get. The length and diameter of the pipe exiting the cylinder determines how fast the air will move and consequently how large the negative pressure is. A small diameter and long pipe will produce its highest negative pressure at the lower rpms while a short and fat pipe will produce good negative pressure at higher rpms.

The large tube acts like open air at low rpms. The small tube is too restrictive at high rpms. A nice medium tube is not too restrictive at high rpms and not too much like open air at low rpms. The medium tube is probably what's on most sport quads. Most utes have small tubes.

 

thats why drag pipes are not just straight pipes, they have a reverse megaphone design to them.

 

about the possible valve problem.I dont think this will effect you but my grandpa told me one time that if you didnt run an exhaust pipe and the motor sucks cool air back up in the motor then it might warp the hot valves.Maybe this is what no exhaust at all would do to the valves.

 

<div class="FTQUOTE"><begin quote>Originally posted by: DS650powe

thats why drag pipes are not just straight pipes, they have a reverse megaphone design to them.</end quote></div>

A lot of them are straight pipes. Most sites I've read says the megaphone is a myth and doesn't do anything. I don't know.... Maybe if it was shaped like a tractrix horn..... [img]i/expressions/face-icon-small-happy.gif[/img]

http://www.google.com/search?h...orn&btnG=Google+Search

It should work on the exact same principle as a ported speaker box. In the box, the speaker is pushing out at the same time the air in the port is also pushing out, making it much louder at the port frequency. In the engine, the piston goes down at the same time the exhaust is still going out, making the vacuum on the carb much stronger. Kinda hard to wrap your mind around at first....

 

<div class="FTQUOTE"><begin quote>Originally posted by: QWODER

about the possible valve problem.I dont think this will effect you but my grandpa told me one time that if you didnt run an exhaust pipe and the motor sucks cool air back up in the motor then it might warp the hot valves.Maybe this is what no exhaust at all would do to the valves.</end quote></div>

Grandpa may have been on to something there. I guess it would depend on the cam design and the rpms. If the exhaust valve is still open while the piston is going down and the rpms are low enough, I could definitely see that happening. Assuming the air is enough to warp the valves though.

My grandpa used to say the same sorta thing about running with no exhaust.... you'll burn your valves. I don't think he meant running no muffler though, just no pipe at all.

 

so say i go rideing today without my baffel in and dont rejjet today will i loose power or am i better off leaving my baffel in for today and waiting to rejjet first befor i take it out, agien?

 

Every quad I've taken the baffle out of has turned the plug black. If the plug is black, that means it rich. If its rich, you will lose power. Take the baffle out n see if it has more power before you head out riding. Check the plug too.

 

it will not hurt it unless you are running a short header. That is what will burn a valve on a four sdtroke, not gutting a muffler. If the header isnt long enough the air can be sucked back in at the wrong rate.

 

<div class="FTQUOTE"><begin quote>Originally posted by: JustRandy

Every quad I've taken the baffle out of has turned the plug black. If the plug is black, that means it rich. If its rich, you will lose power. Take the baffle out n see if it has more power before you head out riding. Check the plug too.</end quote></div>

now I don't mean to insult you, but what you posted makes no sense. If you take the baffle out, you need to jet UP, making it richer. And now if taking the baffle out makes it richer, then why do you need to make it even richer by jetting up?

Maybe those people just tried to compensate for the jetting by riding with the choke on?