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Yoshimura 77 muffler...with or without silencer?

2K views 4 replies 4 participants last post by  cbrlocal 
#1 ·
Just picked up a yoshimura 77 muffler for my 250 Repsol. Any pros or cons of installing or not installing silencer that it came with. Will leaving it out hurt performance? Thanks.
 
#2 ·
Just picked up a yoshimura 77 muffler for my 250 Repsol. Any pros or cons of installing or not installing silencer that it came with. Will leaving it out hurt performance? Thanks.
In dyno tests I've seen, there have been instances where not running a baffle will produce less power.

You can try it without, but most single-cylinder engines just don't sound that good when the exhaust is too "open". It's also nice to be able to be quiet if you want, then have a bit more exhaust note when you decide to get the revs up. Running a baffle usually accomplishes that.
 
#4 ·
Regardless of silencer ...

Pro ...
The look fookin kool. Honda should take some styling cues for the OEM.
The loud pipes save lives crowd will love you ... and you too will be as deaf as they are after a week or so.

Cons ...
Too loud ... your right ear will be begging you to put in a silencer after an hour at full throttle on the freeway. Even after you put in the silencer you will want to put the OEM back in within a week.
Bike is slower ... the Yoshi is lighter and breathes better ... but ... after having both in at the same track day I set faster times on the stock and hit a higher terminal speed down the main straight with the stock. This is as measured with a high end GPS lap timer.
So unless you put a piggy back system on and tune it on a dyno the engine will run richer ... and will foul the plugs sooner and produce less power.
They wear through the can when you bin it on the right hand side at pretty much any speed ... the OEM survives pretty well, just needs some sanding and paint to get it looking reasonable.

My suggestion is to sell it and put the money towards a Racetech cartridge emulator kit to get the front end working half way decent. Or ditch the OEM tyres and get some Diablo Rosso II's. Or do what I did and ignore all advice and just learn from it ... that's the fun of bikes.

Enjoy.:wink2:
 
#5 ·
My Leo Vince has been great. Yes it's loud, but wind noise is usually even louder than the loud pipe. Hearing protection is mandatory, regardless as to whether you run an aftermarket pipe or OEM.

Dyno tests even without a piggyback system show increased torque across the rev range, baffle in or out. Of course these are dyno tests, so they're conducted at WOT and don't accurately convey part throttle/around town cruising. My butt dyno though, which is generally pretty accurate, seems to be equivalent or better than the OEM muffler in any instances I've experienced. It also sheds quite a bit of weight. My spark plug has always looked normal before and after the swap.

As long as you're just doing the muffler and not an entire pipe swap, you should be good. I also generally enjoy the muffler more with the insert in place, just an FYI.
 
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