Kerker 4to1, can you replace the innerds??

Hi,
Once I get the timing done and the carbs back on and tuned, I want to see about replacing the inside of my Kerker. When I first fired the bike up LOTS of rust blew out the back. I'm worried that the insides are all rusted out and may cause problems. Is it possible to get replacement innerds?
Great site, already found tons of good info.
Thanks.

Yes, yes you can. I saw somebody selling a batch of NOS Kerker baffles with end caps on ebay a couple years ago. I wish now that I'd grabbed one, just for the end cap as mine broke when I was trying to get it out.

Here's what ya do: Pull the muffler, remove the set screw that holds the end cap on, then work and work and work until you get the end cap off. Pull out the perforated baffle pipe and clean all the rust off, bead blast it if you have the means, maybe spray it with some high heat BBQ grill paint to keep it from rusting further. I took my megaphone to the car wash and blasted it out (Actually, I blasted out my whole exhaust system.)

Next, go to the store and pick up a set of Chore Boy stainless steel scouring pads. If you undo the little twist in the middle, you can unwrap them and they're perfect for packing your baffle...


Welcome to KZRider! Look around, you'll find a lot of good technical resources here.

PS Another of our members, TwoWheeledTerror just got an MGB, you guys should trade notes.

ive allways removed the baffles and just run the end cap it will be quiet when youre just cruising around but will have a little less restriction on the top end!goodluck,happy wrenching!:whistle:

inside the kerker muffler is a steel wool pad (about 12" square and an inch thick) that wraps around the baffle.

my steel wool pad was rotting away, spewing bits out the end cap and plugging the end cap.

i've taken out the steel wool pad and am going to try the bike in the Spring with just the baffle insert and she how she sounds.

When I had this thing apart I started it with the baffle out, with just the end cap, and the short version with no muffler at all. The last one sounded the best, better than the empty megaphone, but was also the loudest and I have to wonder how that would affect the scavenging. I've settled on packing the thing with copper wool, it seems to strike the best balance of tone and volume...

Seems like one should be able to tune the back pressure by varying the amount of packing material, yes?

Thanks for the info, it's good to know that it's repairable, I'd hate to toss it, it still looks good on the outside. My neighbor (he and his wife ride harley's) thinks I otta just pull the innerds out, it'll sound better (maybe when I go visit my ex, she hates straight pipes).
Once the temp got above freezing, I suited up and pulled the bike into the sun and got the timing set and the carbs on.
By golly, once the fuel started flowing (had to whack one of the carbs to get the float unstuck so it would QUIT flowing) she started right up :woohoo: , warmed it up and played with the air screws, turn 'em in ~3/4 from 2 turns out so I'm sitting about 1-1/4 turns out. I tweaked a little and it idles nice.
Took it for a quick ride, and it pulls well, no bogs or hesitations. I must have lucked out and got it about right.
I do need to get a manometer or vac guage setup to make sure of the balance, then do the plug dance.

But am happy for the moment.:woohoo:
Thanks for the replies and tips, maybe this week I'll get the nerve up to see what's left inside that pipe.

guitargeek, thanks for the info on twowheeledterror, I'll have to ping on him in the next day or so.
interesting quote, I had to go translate it.
Thanks all

You could also just go buy a bag of proper packing material from your local bike shop. Imo it should last you longer (won't burn out) and give good tone.

I've had good results with this stuff on my offroad and street.

80.127.27.163/sp2003/English/Prospekt_US.pdf

Post edited by: savedrider, at: 2006/01/23 22:59

Thanks for all the info about the Kerker innerds.
I finally got around to pulling it appart,
Perforated baffle pipe???
I got a couple pounds of runs and a couple of inner pipes.
Looks like I gotta find replacements or find a way to make new.
Here's a Pic of what's left inside.... maybe.

Post edited by: BRGMGBGT, at: 2006/01/28 15:15