[Old Guy]

Hello from NC, I am new to the Harley world, just bought my first Bike It is a 2004 Sportster 1200 XLR. It is stock with stock exhaust, but does have a screaming eagle air cleaner on it. The bike seems to run good, but it sounds like a Honda. I would love to have a little of that traditional Harley sound but don't want open pipes, that would be to much noise for me and the neighbors. I have read in a couple of posts that you can drill out the center plate in the stock mufflers, how do you do that and do you recomm end this. With that being said should I or would I need to change jets or other carb modifications. Any other secrets that are not expensive to do on my bike that would add to the performance. Thanks in advance for you help and I am looking forward to spending more time here on Bike Talk.

[Art_NJr]

Originally Posted by Old Guy

Hello from NC, I am new to the Harley world, just bought my first Bike It is a 2004 Sportster 1200 XLR. It is stock with stock exhaust, but does have a screaming eagle air cleaner on it. The bike seems to run good, but it sounds like a Honda. I would love to have a little of that traditional Harley sound but don't want open pipes, that would be to much noise for me and the neighbors. I have read in a couple of posts that you can drill out the center plate in the stock mufflers, how do you do that and do you recomm end this.

Get a hole-saw that will fit down inside the mufflers & an extension for your drill. That had already been done to the '00 Sportster I bought used & the bike runs great that way. It'll "nose over" on the very top end, but for normal riding it's fine & not much louder than stock. Definitely quieter than with SE I (Cycle Shack type) slip-ons.

With that being said should I or would I need to change jets or other carb modifications. Any other secrets that are not expensive to do on my bike that would add to the performance. Thanks in advance for you help and I am looking forward to spending more time here on Bike Talk.

Only other things you need to do to complete the "Harley Tax" are to go up one size on the main jet (leave the slow alone) & set the idle mixture screw @ 2.5 turns out for the baseline - may have to go up to 1/4 turn either way from there to hit the "sweet spot". Adjust it only when the engine's warmed up.

The idle mixture screw may still have the cap over it & if so, just (gently) drill a small hole in it, thread a sheet-metal screw in (gently) by hand, then with something like needle-nose Vise-Grips, grab the head of the screw & snatch it out - the cap will come with it. Then you can get to the idle mixture screw. Run it in all the way (gently) then back out 2.5 turns.

Also, get the factory service manual if you haven't already - worth every penny.

[SPORSTERBOY]

I pulled the baffles out of my stock pipes, and for the noise factor not much of a difference, even pulled the slip on's off and put on 6" tail pipe slash cuts, same result, best way is to just get some new slip on's, but the same effect is there, the only way I think to go louder is to replace all together to eliminate that cross over bar on the pipes. you could always get drag's for real cheap and put baffles in to tone the noise down.

[Art_NJr]

Originally Posted by SPORSTERBOY

I pulled the baffles out of my stock pipes, and for the noise factor not much of a difference, even pulled the slip on's off and put on 6" tail pipe slash cuts, same result, best way is to just get some new slip on's, but the same effect is there, the only way I think to go louder is to replace all together to eliminate that cross over bar on the pipes. you could always get drag's for real cheap and put baffles in to tone the noise down.

Except for changing to quality slip-ons (which is the best way to go), all that hurts performance. Also, the crossover pipe on Old Guy's '04 Sportster doesn't show like it does on our earlier models & is the lower mount for the exhaust.

There's only one application that completely removing the baffles in stock mufflers worked in - a Land-Speed-Record bike in the Production class where the rule is, "Stock appearing motorcycle; all performance modifications must be out of view." The bike really wasn't much louder than stock, but it had no low-end power. Didn't matter in that situation as top-end HP was the only consideration & since the exhaust must appear stock, the only way to get maximum flow was to remove the baffles altogether.

When I bought the '95 bike it had SE I slip-ons with the baffles removed & those are the only things the previous owner didn't save. The bike was such a dog on the low end that I put the stock mufflers back on until I found a set of baffles for the SE's. Contrary to popular belief, it's not the loss of backpressure that hurts low-end & mid-range power, it's the "reversion" waves going back up the pipes unrestricted. Baffles break that up & the crossover equalizes what's left over - lose the crossover, you lose lots of torque & 5-8 HP too.

In short, if you want to improve performance & get more of the "real Harley" sound but not get real loud, drilling the center plate out of the stock mufflers or going to aftermarket slip-ons & retain the crossover is the way to go. And no Sportster exhaust system will out-perform stock pipes w/crossover & quality slip-ons from idle to redline - any other system only makes power in a narrow rpm range & that's a fact.

[hotroadking]

FWIW

shop all over and look for a set of Khrome Werks or Cycle Shack simple slip ons for your bike.

Put the stock ones in the garage, attic, ol ladies closet and keep in case you need an inspection sticker at some future point.

These will provide great sound, good performance and are under $200 for a set.

Khrome Werks

Best buy you can get..... they have a returns section, check it sometimes you find mufflers that are returned for some reason.

[Buckeye47Fan]

I saw on ebay, a set of cycle shack slip ons for 139.00. They were slash cut and brand new. You might wanna check it out.

[Old Guy]

Thanks everyone for the great info. I think I will drill out the front plate and leave the back one alone for now, just to see how it sounds. One post said go up one jet size in the carb, what jet size should be in the carb in stock form. That way if is different than what I have I know some one has changed the jets before I got the bike.
Thanks again.

[Art_NJr]

Originally Posted by Old Guy

Thanks everyone for the great info. I think I will drill out the front plate and leave the back one alone for now, just to see how it sounds.

Doing just one muffler will mess up the tuning big-time. Drilling the center plate out of the stock mufflers does not make the bike much louder, but it sure does increase exhaust flow & consequently intake flow.

One post said go up one jet size in the carb, what jet size should be in the carb in stock form. That way if is different than what I have I know some one has changed the jets before I got the bike.

Hard to say which main the bike came with - prior to '04 a 175 main was baseline for a 1200 Sportster, but the heads are different on '04-up models & I've seen 180 & 185 main jets come stock in '04-'06 XL1200's. A 180 would be a good baseline, but you may need more with improved intake & exhaust flow.

The '04-up XL1200 heads are basically the same as the Buell XB heads & flow more than any H-D has put on Sportsters before. And '04-up XL1200's come with the W grind cams, which previously came only in the 1200S "Sport" model, '98-'03. Significant difference in timing & more overlap.

Always think "system" instead of individual parts & the engine most assuredly will not like you doing something to one cylinder that you don't do to the other.

[Old Guy]

I meant I was going to remove the front plate on both mufflers and leave the back plate (the one closer to the engine) alone for now.

[zwhitr]

Originally Posted by Old Guy

I meant I was going to remove the front plate on both mufflers and leave the back plate (the one closer to the engine) alone for now.

There is only one plate its about 8" from the rear it redirects the exhaust inside the muffler.

[Old Guy]

OK, thanks will check it out.

[08XModel]

Originally Posted by Old Guy

Hello from NC, I am new to the Harley world, just bought my first Bike It is a 2004 Sportster 1200 XLR. It is stock with stock exhaust, but does have a screaming eagle air cleaner on it. The bike seems to run good, but it sounds like a Honda. I would love to have a little of that traditional Harley sound but don't want open pipes, that would be to much noise for me and the neighbors. I have read in a couple of posts that you can drill out the center plate in the stock mufflers, how do you do that and do you recomm end this. With that being said should I or would I need to change jets or other carb modifications. Any other secrets that are not expensive to do on my bike that would add to the performance. Thanks in advance for you help and I am looking forward to spending more time here on Bike Talk.

If you drill the baffles out you might not like the sound. I did that with a 05 883 custom and ended up putting V & H straight shots on . The drilled mufflers tended to gurgle somewhat. Hope this helps.

Kevin

[Old Guy]

Kevin, thanks for the info, you were so right. Drilled out the plates in both mufflers and it doesn't sound good at all. Big mistake should have left alone and went the slip on route. But even with the plates removed and the pipes are straight trough they are not that much loader, they just don't sound right, they gergul. Will maybe try a set of Cycle Shake slip-ons later on when finances permit.