opinions on open pipes

[pat english]

whats youre opinion on open pipes?bad for the motor?too loud?

[Re-run]

Personally I don't care for open pipes, especially riding behind them, but it is a personal thought. I would argue the loud pipes save lives thing as that one never really goes anywhere.
I only say, remember your neighbors if you think about doing open pipes.

On a more technical side, pipes such as drag pipes may require a rejet, this is based mostly on your carbs. Thea earlier cb750 carbs from 69-76 usually required a but of a larger jet. The 77/78 could take drag pipes with pop filters and many times did not need a rejet, just a retune with the fuel screws.
They also will not harm the engine. now if you have pipes that barely reach the bottom of the frame, then there might be the potential for damage.

Performance-wise, you really will not gain anything over a good 4-2 or 4-1 system such as a yoshi.

now I have not seen a long straight pipe such as a muffler with a baffle removed. obviously louder but I am not sure how much. I thought about trying it but I cant the damn baffles out of mine!

[pat english]

hmmmmmmm.well if you dont think ill gain any performance then i preolly wont do it.andi think youre right about the loud pipes save lives thing.when im in my work truck,i dont even hear a bike till its passing me.and half the time i dont see it.

i havnt tried taking the bqaffles out of mine yet.i know they come out though cuz the sell new ones.maybe ill try it and see how loud it is.

but yeah i was thinking about building a 4 into 1 system.cuz i dont wana pay$400 for 10 bucks worth of steel.i might work on that next week.

[pat english]

i took a closer look at the pipes today.dont know what youres are like,but mine have a lil tack weld holding the baffles in place.you think if i take the baffles out i will have to re jet the carbs?how bout for a four into 1 system? if i run 1 of those will i need re jetting?

[Re-run]

I cant see any welding on mine so they could just be jammed in tight.

As for rejetting, on average, you should not need a rejet for just opening up the pipes except with maybe drags. This is on average, but if you got pods or a k&n in there, then maybe another step up BESIDES what you may have to do for the intake change.

On my 78K, I put in a k&n and had to make NO changes. You carbs are different though and so may require a change. I would just buy jets and not drill them. Jets are designed to operate like a venturi and drilling them destroys that.

[pat english]

Re-run wrote

I cant see any welding on mine so they could just be jammed in tight.

As for rejetting, on average, you should not need a rejet for just opening up the pipes except with maybe drags. This is on average, but if you got pods or a k&n in there, then maybe another step up BESIDES what you may have to do for the intake change.

On my 78K, I put in a k&n and had to make NO changes. You carbs are different though and so may require a change. I would just buy jets and not drill them. Jets are designed to operate like a venturi and drilling them destroys that.

what will happen if i run open pipes?will it brake down rite away or will it take some time?i think im just guna buy a 4 into 1 system.i thought about it and it would prolly take me all week to make some up and theyd prolly look crappy.

[Re-run]

No way to say really but usually the slightly lean caused by open pipes will make things run a bit like crap before any damage happens.

[LukeM]

Based on the limited reading I've done so far (Clymer and Haynes manuals), if the exhaust is less restrictive, all other things being equal, the motor will run lean.  With the decreased back pressure, when the motor comes around on the intake stroke, some of that intake charge will go out the exhaust port, meaning less fuel and air in the cylinder for the power stroke.  That's why you jet up one or two steps when running open pipes.

Just my opinion, and what I've gleaned from the research I've done so far.  I do like the sound of the factory pipes on my bike, and find my son's CB550F with straight pipes a bit obnoxious and loud.  However, I can chalk that up to him being young and riding his first bike.  He also believes loud pipes save lives, which has some merit, but is more of a philosophical discussion.

My $0.02 worth.
Luke M

[pat english]

yeah im a youngster too and i like loud everything.but i do know that louder is not faster.

i just made up some sraight pipes yesterday.(and yes they look like crap.sounds great though.
but this is only guna be temporary.im guna order 1 of those 4 into 1 systems.

and i do agree with you on the look and sound of the stock pipes.but my bike didnt even have the stock pipes.

does anyone know of anyone who makes an aftermarket 2 into 2 system for cheap/fair price?
(those guys selllin originals are asking way too much)

[Re-run]

Well the cheapest you will probably find will be Mac. they do a 4-2 system but it will still cost about $300 bones new. Another option would be to see if you can find some original pipes that are thrashed but have good headers. Whack off the bad parts and get some slip ons. You get more custom choices BUT the downside is that our pipes have relatively small O.D. and so you would need to get 4 3 or so inch pieces of exhaust pipe and size each end to match, if you stick with the 4 muffler look, and then weld shut to openings.

[Jaren]

Loud pipes really do save lives. It's harder to see us, so why not make it real easy to hear us?

[pat english]

yeah youre kinda right.but when im on the freeway in the car or in my work truck,i dont really hear a bike untill its right next to my door.

i found a set of original pipes.a guy on craigslist.got em for 120.the 4 into 4 look sweet.theyre really quiet but they look great.i need to post up some pics.

[Re-run]

Jaren, there is no evidence to support that. In possible fact, louder pipes might make it worse.
Say a person has their pipes really loud. When you are in  a cage, you might hear them but you might not know which direction the noise is coming from as the sound bounces around inside. You might be looking around and miss the rider.

Also, as pat said, many times on the hiway, you will not hear the pipes till they are right next to you. Not really much advantage there. many times people say "loud pipes save lives" only because they heard it from someone who knows a guy whos friend was "saved" by them.
One thing loud pipes DO do is give riders a bad name. We cant really afford that much as there are very few of us and it is easy, therefore, to push legislation on us and most people will back it cause the first thing the average person thinks of are riders with loud pipes that they dislike.

Now a person could argue till blue in the face about loud pipes but the fact is, there is only anecdotal evidence to support them. I don't care much one way or the other but I won't ride behind someone with open pipes, not for long anyways.

[vern401]

Pulling the Baffel out just makes it loud is all. I had my muffler off and started it and spent the next day in the dog house for waking the wife and baby.