Hey folks,

Put a Dyna muffler on the other day with shop made adapter which mated the slide bolt at its farthest forward position with the back hole in the stock bracket. That translates to a pipe about 6" between header and muffler. The Dyna muff is the longer 19" version, so the whole thing ends back about even with the rear brake hub lever.  





The sound isn't too bad, not as loud nor deep as I predicted, but better than stock. Fine for not waking the neighbors, but just a tad more tame than I had in mind. Don't misunderstand, I've had a glass packed megaphone on an SR500 before that was downright embarassing, and I don't want to go there again, but there has to be a happy "in between."

Just out of curiousity I decided to test the bike without any re-jetting. I was certain the idle circuit was a bit rich from the small puffs of black on short throttle blips, but I haven't run it long enough, or swapped and read plugs enough to really read other throttle positions.

One thing that really surprised me was an obvious lesser pull above 75mph and my top speed had dropped from a bit over 85 with the stock can, to a shade over 80 with the Dyna. Even with a possibly lean (most likely) main jet, it would seem that reduced restriction would have allowed at least equal top speed. Frankly, I'm puzzled...

I've now ordered a similar length large can "turn-out" style with less baffling.



I predict it WILL absolutly demand jetting, where I think the Dyna might have been ok as it was, since it ran well except the top speed, and had very little backfire, or notable hotter header pipe. (I've been around hot exhaust and turbo systems enough to be a fair judge of the temp by just feeling the heat from a few inches away.)

I've also been reading the thread discussing the difference in throttle response between the direct pull Amal and vacuum pull stock carb. It has me re-thinking my consideration of a "dial-a-jet" and popping for an Amal, but I remember how we used to hate the old leaky ones on our Nortons. Hope the newer ones aren't as unfriendly  

Comments, or guideance of more experienced Savage tuners greatly appreciated!  

I suspect you're right on it with the need for the #155 main jet. However, the tank was cleaned and sealed, and carb rebuilt by the old man I bought the bike from a couple of months ago. I think he must have done it well, as the bike has run well and done very little backfiring while I've had it. Even with the muffler change.

I'm not going to tinker with jetting just yet though. I want to try the other pipe I have on the way for loudness, and make a decision between it and the Dyna before committing to carb tuning.

Lancer is dead on. Without rejetting, your engine is starving for fuel at the top end speed. I put on 155 main and the  beast cruise nicely at 70mph and when there is a need to accelerate, 70-80mph in about 1 sec. Unlike stock muff+ stock carb, it takes forever to acomplish that

Dynobob wrote on 12/31/69 at 16:00:10:



Not at all my intent. Just want to sound test each pipe before I committ to carb tuning for the "keeper" pipe.

A bit of explanation: I am very particular about some things, loudness and tone of exhaust from car or motorcycle being one of them. My taste in guitars and/or amplifiers being another. It seems the only way I can arrive at a satisfactory solution on some things, is to try many things. Trial and error is expensive sometimes, but the resulting satifaction is often worth the expense. On my motorcycle parts, as with guitars, I'll eventually sell some of the discards to recoup some of my costs.

Good points.  I have changed filters, carbs, and pipes/mufflers several dozen times, and rejetted for most of them.  There are indeed differences in sound for every change.  I now have the muffler I like most on my bike, but of course I will continue to try others.

IT IS A LIFESTYLE