Rune Rider Forums banner

Having it " BOTH " ways

6030 Views 23 Replies 9 Participants Last post by  Rich Oas
While at my desk at work today I thought of a way to enjoy my 1.5" holes in the mufflers. I am going to remove my mufflers and bring them to work where I can have two channels tig welded to the mufflers. Then insert a piece of metal into the channels and create a sliding door type closure.
This way you can slide it closed when you want it stock for highway riding , or open it all the way to scare the woman and children in your neighborhood :twisted: or open it half way for a nice mellow tone.
I will hopefully get it done by next week sometime.
Rich K ( Rune Ski )
1 - 20 of 24 Posts
Sliding Door

Hey RuneSki... I feel so cheeated on the technology end... But I do some carpentry work... Maybe a high quality spring loaded cabinet hinge with your hole cover welded to it might work too. Open it when you like and then snap it shut when you like... if there is room. Would ensure no rattle with the slider...maybe :shock:
Great idea, Rich. I like it a lot. Let us know if you find any unforeseen down side.
Down Side on the Left Side:

Black smootty splotch on my kickstand!!!!!!!! Make sure the left side hole is not blowing into the stand when it is retracted!! It wasnt in the way when I drilled it out!! :twisted:
Thanks. I have my hole on the left side more to the rear and lower down away from the kickstand.
Rune exhaust system should go on a diet. Total weight is 32 lbs. :shock:
Rich K ( Rune Ski )
Had to be put the slide show on hold for a couple of days. Mother Nature threw us a pretty good snow storm :snow1: . Over a foot in my area.
My 82 Totota 4 WD plow truck got us out but I have to reinforce the rusted out frame. The bed moves to and frow approx. 3 inches. :eek:4: :shock:
Rich K ( Rune Ski )
Drilling hole in muffler ?

Hi guys;


It has been really informative to hear (read) the evolution of this topic ... hole in mufflers ... since I plan on doing this as soon as the snow melts (which could be April 31st) :shock:

But what I don't yet have a good feel for with the "drilling" is how far into the muffler you drill the hole :?

When I "cut the piggies" on my '98 Valk and then drilled back through the second set of bafflers - it was a straight shot back & I knew when I was through them by the feel of the drill bit. :wink:

But with the Rune ~ I don't want to go too far 'cause it looks like you could get way too excited and end up out the other side ... :eek:4:

Any advice?

Is there a diagram of the inside of the muffler to show the # and position of the baffels? :roll:

Thanks! :D

NH Bill
See less See more
You go thru the outer skin, .050, then there is a perforated metallic shroud right under it about 1/8". Then there is empty space. So, you will drill thru and then you stop because you "broke thru." No big deal.

I love the sound. It is quieter than my V-Star with Cobra pipes.

Ken (i rode in the drizzle this morning to work, 51 miles.... not ice crystals...drizzle. you gotta love South Carolina for its long bike season!)
Not the weekend of 29 Jan because that is the 160m CW contest, and I have to really test out my antenna invention:

Now they want me to go to Kuwait asap
And the Ministry of Telecommunications, Iraq wants to hire me
So I am going to need a trip very soon.
Hi all,

I agree with NH Bill, I’d also love to see an exploded view of the inside of the muffler. If each of the three input pipes has its own chamber/baffle/whatever, it would seem to me that a drilled hole might not pierce all three. Even if it did, the size and position of the hole would probably not be consistent. If that’s the case, the back pressure supplied to each cylinder by each baffle or chamber would be inconsistent, and that would likely cause problems; at the least it might hurt performance. On the other hand, if all three exhausts terminate into a single, common chamber, a hole in that common chamber would affect each cylinder consistently, even though even that could potentially change performance. Whether the change is good, bad or negligible would require a dyno. Perhaps someone planning on doing the mod could do a before/after dyno and report back.

The bottom line for me is that I think I’ll wait until I see a Rune muffler cut open.

Drive safe
Drilling holes

I have to say that the way "WhataMarune" said it is what I was trying to think about saying
glad you put it so see-sink-ly
... important info.
How do we get a cross section picture / view of the muffler? Anyone got an old one or a way to look at Honda's ski-maticks for the muffler?

Would anyone know someone @ Rivco (they must know ~ to be making an after-market muffler) who would share? Eventually all mufflers wear out and theirs would probably be cheeper so they should think of sharing a pic as a good marketing tool (sound like too much of a BS line?).

Ken; Nice shot of your dynorun! :clap2:

Had you done any improvements before this ... like air-box cutting or polishing your heads? :eek:

When you said ..."outer skin, .050" was that 5 hundrediths of an inch? and do you go through the "perferated shroud" for about 1/8 inch making the total drilling depth about ... .05" + 1/8" = a little less than 1/4 inches below the outer skin? I'm so un-scientific in my question - sorry - no engineering background - all libral arts :oops:

And after reading a little of your posting on that antenna site - WOW you must be 1 smart dude!
Be careful and wear your armor :drive1: driving around over there when you go!

Still snowing uo in New England I better dust off my "down-hills" to get any excitement. :D

NH Bill
See less See more
That Dyno Run was WITH the K&N filterbox mod. But, I suspect that not much was added with that mod. We will not know for sure unless someone ponies up to the table and Dynos his stock Rune. 'comeon cheepskates, $50 bucks.

Yes, 0.050 is 5 hundredths, or a really WIDE spark gap on a spark plug, since 0.032 is normal.

Naw, I aint too smart. I just like to do thangs. Many thangs. And riding is one of them.

New trick: riding down the interstate, warming both hands at the same time on the valve covers! You have to lean over really low. But, heck, I am saving lots of dough on heated gloves and you can steer by ESP. It works!!
Dannyhyde doesn't seem to post on this board any more but he's cut open a few Rune exhaust boxes to modify them for his customers. Is anyone still in contact with him: he may have some photos of the exhaust internals he could share with us. ( as long as it doesn't effect his exhaust modifying business that is)
Exhaust Diagram

I know that this diagram of the exhaust system does not show a cross-section of the canister, but since the 3 headers merge into a collector prior to the entering the canister I think the likely hood of each cyclinder having it's own chamber is low, that's my 2 lincoln heads!
See less See more
Logical would agree


Your logic appears very sound :lol: couldn't resist that!

What do you make of the cross-over connected by 11 & 10 to 2 and of the apparent different shape of the two canisters? Any relavance to where the holes are now being targeted to be drilled? :?

NH Bill
I think the canisters are different because of the single sided swing arm and the kickstand on the non-swingarm side, the cross over is for equalizing the exhaust pressure. As far as the placement of the holes
I think it appears that way because of the difference in the shape of the canisters. Remember this is all logical speculation of mine.
Finally got the slide closure mig welded to the muffler. Its an open and closed case,sorry. Haven't put it on the bike yet but I'm certain it will work.
I guess I didn't make a mistake by drilling too large of a hole in the first place. Now I can adjust the sound to however loud or quiet I want.
I'm not going anywhere for a while, much too cold and still snow and salt covered roads do not make for a happy Rune. More info later
Rich K ( Rune Ski )
RuneSki, So how much you gonna charge me for a set of those trap doors?
Hole Plugs

I was just walking by the electrical shop in our maintenance area and saw a set of snap in plugs to close off conduit holes in electrical boxes.. I think the 3/4" hole plug might work real well (and cheap). They simply snap into place.. Course when taken out you need to put them somewhere... This is probably the lowest tech solution for closing off the holes discussed thus far...They come in a variety of sizes. ... even if hole is on a rounded portion of the pipe the 3/4" would probably still work... if flat, you could probably go up to 2"...
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.