drilled stock mufflers

[lamont]

Just scored a nice black 81 R65 with only 11K from a guy in Missouri, the exhaust was painted black and the ends of the stock muffs are drilled out , it sounds cool and I swear its more peppy than my other R65s,of course it could be a pigment of my menstruation,  has any one ever done this mod? Does it make a few more ponies???

[beemer]

Well the only thing you would get over here in the UK were policemen riding the ponies!!!!!

[montmil]

Just scored a nice black 81 R65 with only 11K from a guy in Missouri, the exhaust was painted black and the ends of the stock muffs are drilled out , it sounds cool and I swear its more peppy than my other R65s,of course it could be a pigment of my menstruation,  has any one ever done this mod? Does it make a few more ponies???

Are you parting out the '81?

[lamont]

no, its a keeper

[montmil]

no, its a keeper

Rats!  

Monte

[Justin B.]

I looked at an R100 that had this done, don't know if it really helps or not but louder pipes always make ME feel like I'm going faster!    If you don't like it you can weld the holes bnack in and touch up the paint.

[R65Guy]

For what it is worth....  Back in the 80's Joe Minton of Motorcyclist magazine wrote an article called Black Tie Boxer and he suggested drilling out the rear baffle inside the mufflers to gain a bit of power and give it a throatier exhaust note.   Seems like you needed a 5/8" or 3/4" hole saw and a long extension.  I always meant to try the mod but never have since I didn't have the tools.  Some folks said they just sharpened a long piece of rebar and punched a hole instead.

Neal

[Billmc]

Sooo a response almost 10 years in the making!

I have done this "mod' to every bike I've owned including a Honda S90, a Harley Springer and this Mono and all the others. I don't know if it really helps performance but it sounds like it does 

A 3' piece of 3/4" galvanized pipe sharpened on one end and a 3lb. mall seem to do the trick. I attack it from both ends of the muffler in case its baffled on each end, as it is on the R65. Again I don't know if it helps but it sure sounds better to my way of thinking (good-by Singer sewing machine, hello motor with guts  )
 I never changed anything else and none of them ran richer or leaner afterward, just sounded and the always subjective 'felt' better.

[Bob_Roller]

I did this to the original mufflers a year or two after getting my '81 R65, no change was detected in power or exhaust note .