silly idea? or genius...

[snowbeard]

nope, most definitely silly.

so if one was not concerned with sound dampening on their bike, only correct mixture and compression, etc. how would it be to use a straight pipe on our bikes with a "washer" type plate over the end, and adjust the size of the hole in it by drilling progressively larger to correct mixture?

how would you check to see if you were getting it right if you didn't have a colortune plug? supposing one started with too much constriction it would be rich off the start, and lean out as the hole got bigger? or would it just not be able to pull any gas out of the bowls at all...

this is all theoretical as I can't seem to make time to change the damn oil in my forks even, but humor me (like you guys don't already, eh!)

thanks!

[Superfly]

I have Mac's on a Yamaha Vision, and on my GS450s. On the Vision, I have the straight-thru Mac pipes, some have been known to weld a washer over the hole (to constrict the airflow)

I have not had a set of the "reverse flow baffels" for the Mac's, but I have not dis-assembeled the Mac's on my gs to figure it out yet. But that is an option, and has been done.

[jimcor]

Pretty much the same concept as cutting a straight pipe internal baffle shorter to make it run leaner (less baffles). That's the way I did it on my '72 XS2. I was looking for loud and found it in spades. I don't think it ran as well as the stock setup tho'.

[rphillips]

Supertrap 4 into 1 pipes, have an adjustable opening on the outlet end of their pipes. Their ads say they are the best thing since sliced bread, but I really haven't heard a lot about them, good or bad. They've been around since the mid 80's, and I don't know of any other manufacturers who have adopted this design.

[Macmatic]

Would two 'busa cans mated to a stock GS750ES exhaust be TOO free flowing? The megaphones on my exhaust are pretty dented and scraped but the pipes are clean and solid so I bought a set of 'busa cans on eBay...but now I'm wondering if it'll be too lean.

I plan to get a Carbtune before I ever try and start this thing again. The whole bike is apart now but I hope to have everything back on the frame in about two weeks.

/\/\ac

[LW_Icarus]

I ran a straight megaphone on an old thumper,once it was jetted properly it ran 125% better (seat o' the pants dyno)

I would probably skip the washers and just jet it to run right. not only will you have a loud bike, but then youd have a fast bike too

[gspaul]

My grandfather had a Vincent , remember those big v-twins?
Anyway he had it tuned for straight through raceing pipes,but he also made up a large washer with a small hole hinged on the end of it, this was operated by a lever/cable on the handle bar's.
This was so he could ride through town's without attracting to much attention.

[Cajun Cycler]

Actually before I found a set of pristine pipes I did that to meet the inspection critiera for the State. Then I discovered after all that, the 79 model was exempt from the baffle requirement due to the age of the bike. Duh. I made a washer type baffle by bolting a round metal electrical box with the center punched out inside the hollow pipes and fitted different sized washers till I got the desired sound and back pressure.