Need help, input, information and a hug on running issues!

[TopCatGr58]

Hey Ras,

That'd be nice to see. Glad to hear about them, just that those type of parts are probably as or more rare than the OEM exhausts themselves, and so I still doubt they are true OEM slip-ons on his bike. Photos of his bike, pipes and such would be good for us to review.

I know I've seen the megaphone/cone shaped aftermarket slip-ons that "look" like OEM's and so could be confused with true labelled OEM badged slip-ons.

Example from MikesXS:

"Dunstall" style replica Universal 27 3/4" motorcycle muffler reverse cone
$59.95 USD ea

An easy way for him to be able to tell if they have much backpressure potential is to just stick a long stick down/up thru the center hole, and if it goes in a few feet, then it's just a straight thru muffler and would not have much backpressure.

Would be curious to know the construction of the ones you have as well. We know the OEMs have prominent layers and reverse direction sections, so wondering if the ones you have are built similarly or are open straight thru??

IF they were open straight thru, I would wonder how Yamaha would have certified them as meeting the same specs as their OEM mufflers!?

T.C.

[Rasputin]

I have to work tomorrow but I will get a pic of the pipes and badging when I get home. As long as my CRAP does not kick in and/or too much beer gets involved.

[Rasputin]

Hey Ras,

That'd be nice to see. Glad to hear about them, just that those type of parts are probably as or more rare than the OEM exhausts themselves, and so I still doubt they are true OEM slip-ons on his bike. Photos of his bike, pipes and such would be good for us to review.

I know I've seen the megaphone/cone shaped aftermarket slip-ons that "look" like OEM's and so could be confused with true labelled OEM badged slip-ons.

Example from MikesXS:



An easy way for him to be able to tell if they have much backpressure potential is to just stick a long stick down/up thru the center hole, and if it goes in a few feet, then it's just a straight thru muffler and would not have much backpressure.

Would be curious to know the construction of the ones you have as well. We know the OEMs have prominent layers and reverse direction sections, so wondering if the ones you have are built similarly or are open straight thru??

IF they were open straight thru, I would wonder how Yamaha would have certified them as meeting the same specs as their OEM mufflers!?

T.C.

I stuck a long screwdriver in there and it stops dead at 5 3/4 inches. House time now so will try to get a few pic's tomorrow.

[motoman]

Would be interesting to see. Myself, over the thirty plus yrs. assocciated with these bikes, never heard of Yamaha slip-ons. I do know that Yamaha replacement exhaust(complete left or right side) had the EPA tab welded before chroming on inside rear of muffler itself. They also didn't have the access bolted holes in the head pipe. I just know this from the NOS left sidereplacement I had put on my Venturer some years back. If those don't have the Yammy part no. along with the Yamaha name on them, they are not Yamaha. I know, still skeptical and doubtful, but interesting to see if true.

[motoman]

BTW, not doubting Rasputin has Yamaha slip-ons, which may be a replacement for the XS twin or tripples series. Only other option would be the XJ series in all cc's which had slip-ons. The XS1100 series, if needing replaced, as far as factory replacement, the whole left or right side minus the #2 or #3 head-pipe, and of course that replacement had the EPA tab on it which showed it was a replacement that still met those regulations.

[donebysunday]

BTW, not doubting Rasputin has Yamaha slip-ons, which may be a replacement for the XS twin or tripples series. Only other option would be the XJ series in all cc's which had slip-ons. The XS1100 series, if needing replaced, as far as factory replacement, the whole left or right side minus the #2 or #3 head-pipe, and of course that replacement had the EPA tab on it which showed it was a replacement that still met those regulations.

My SH has one muff with 3 big rivets in it at the back and the other does not. Can't really see any difference other than that. No clamps ?

[motoman]

My SH has one muff with 3 big rivets in it at the back and the other does not. Can't really see any difference other than that. No clamps ?

Not exactly sure what that has to do with slip-ons, which yours are not if originals.

[Rasputin]

Okay here are some pictures of what I have here. I may stand to be corrected for sure just ask my wife!
The set I have do have the yamaha part number stamped in them. They also have the EPA thing fastened to them.
They were on an XS11 set of headers when I got them so mayhaps other models fit or will work with them.
I tried to clean the pipes up a bit so you could more readily read the numbers but after 4 minutes and more beers I decided eff it they can read the numbers without polishing.
So long story short here is pics of what I believe to be the Yammy version of the aftermarket exhaust.





















The Yamaha part number on each is Yamaha 3H3-n 14721 and Yamaha 3H3 14711.
So here is my exhaust in all it's glory. Please let me know if I am wrong on this.

[motoman]

Well, they are the shorty up-swept style used on 79-81Specials AND the 81 Venturer, but inserting internal,(which is only way they would go on Specials since no short collector extension like on Standards(Venturer exempted also), would be the only possibility for a Special. Not having that short lead-in piece angled a bit has me wondering it they would even mount up and still stay located properly where they insert. Guess one could do some measuring, comparing hanger mount location and cross-over location againt a Special(79 opposed to 80-81 would likely have different hanger point).