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AEmedic

Uncorking 2007 XR650R

41 posts in this topic

I just picked up a new XR650R and am in the process of ordering the parts to uncork it.

Does anyone have a comparison between the stock exhaust with the hole saw mod and the stock exhaust with the replacement spark arrestor?

If they are "exactly" the same I guess there is little reason to buy the replacement, since it is unlikely that the stocker will ever go back on the bike. Although, it is always nice to be "able" to make the bike stock again.

If the replacement is even a little more quiet than the moded stocker that is likely the way I would want to go.

Any advice?

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The HRC tip makes better power than FM Q pipe but you know it's on there for sure it's loud.

Cheap I think mine was about 80$ it sits in a box on the shelf .maybe it was a waste of 80$?

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I did the hole saw method and have always been completely happy with it. It runs very well and does not seem too loud to me at least compared to other 650R's I've ridden with that had aftermarket pipes. For absolutely free, you can't beat it. One thing that should be done is to dremel down the jagged edges from the hole saw afterwards. It will make the flow a little better.

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I have heard that the hole saw mod does not make it too loud, but is it louder than the HRC tip?

I went straight from a stock tip to HRC tip so im not sure...but considering the HRC tip makes more power, its proble louder.

Try the hole saw to save some cash

And dont forget the smog pump...the pump comes stock on every 2007 XR650R, with a $25 kit form XR's only you can loose 2 pounds and gain 2 horsepower :thumbsup:

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I had no idea that the smog crap was on all of the 07s, I guess if it wasn't 10* in my garage I would have looked closer at it... I guess that is also on the list to order tomorrow.

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I just finished uncorking my 07 yesterday. I drilled the stock tip and was surprised how quiet it was. I'm happy with it...what a huge difference uncorking makes. I drilled the stock tip because I thought no matter what I'm not going to use it. So why not try the free mod first and if you don't like it for some reason then you can spend the $100 on the HRC tip.

If you do drill it, do yourself a favor and use a bi-metal holesaw (bout $13 @ HD) and spray a couple squirts of silicone spray where you're gonna be cutting. It makes the cutting buttery smooth and it also keeps most of the shavings clumped together for easier clean up. I drilled my tip while it was still in the bike then took it out and blew the shavings off. The spark arrestor screen caught any shavings that made it inside the tip. It took me all of about 5-10 minutes...including cleanup.

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Uncorking obviously makes a ton of difference. I really want to know the differance in the exhaust note between the HRC tip and the drilled tip. Sounds like I am going to drill it out and go with that, but I want to know prior to drilling...

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I was confused by all the tip drilling talk and options and noise and did a lot of investigating a while back. There were a few guys here that clarified some things for me, which I thought I'd pass along.

Just drilling the tip of the stock exhaust (drilling out the small tube from the outside of the exhaust) is still pretty quiet because both internal baffle plates are still in there and that is where the next big restriction is. But this is still pretty choked up, and NOWEHERE near uncorked.

The "second" stage in drilling the stock tip is also to drill the innermost baffle out to 2 inches also. To do this you have to remove the tip from the exhaust and drill the baffle from the other direction. I didn't test this case but I was told it was around 96 dB. It was recommended to me to drill the innermost baffle to something less than 2 inches if you want to keep it more quiet but provide SOME additional flow, but the exhaust sounded funny (made a chirping like noise) when I drilled it out to 1.25 inches. But it was too loud for me at 1.25 inches, so I quit and moved on to an FMF Q2.

There is a "third" option for the stock tip, which is the closest to the HRC tip in flow, but you have to completely clip off the innermost baffle and drill the remaining baffle and replace part of the screen over the hole you drilled. I would imagine that is not quite as loud as the HRC tip because there is still some restriction, but probably close. I have one a guy sent me to test, and will test it if I ever get a chance.

Some numbers to ponder:

Stock tip at idle (1400 RPM): 79 DB

Stock Tip at 3250 RPM: 87 DB

The drilled stock tip (both innermost baffle and outer pipe drilled out to 2 inches) is 96+ dB at 3250 RPM.

The HRC tip is around 103 dB at 3250 RPM (I didn't test this, another guy did but with the same brand meter and method I used)

FMF Q2 at idle (1400 RPM): 83 DB

FMF Q2 at 3250 RPM: 90-91 DB new, 93 DB after 25 hours on the packing.

The difference between 87 (the stocker) and 91 (FMF Q2) is a lot. But I don't feel the Q2 is too loud. The difference between 91 and 96 is quite a bit to the ear.

And any of these, except corked up, bark under heavy throttle.

I used a radio shack digital sound meter and a digital tach, measurements were taken a 22 inches, 45 degrees from the pipe. To me 96 dB is too loud (to the people who have to hear it). I wanted something less than 94, and the Q2 got me there. When I first tested the Q2, I was getting 95-96 dB, but it turns out I was too close to my house and there was some major echoing going on.

The main reason I uncorked was to run cooler (bike overheated too often when I was riding with my kids) and the HUGE ease of starting. But I have to admit, I like the HP gain too.

Hope this helps. Like I said, I'm not the guy who came up with all this, I just did some testing and took notes.

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When I drilled mine, I used a 2" hole saw and I did it while still on the bike. The only thing left is the spark arrestor screen with the cap on the end of it that sticks inside the muffler. If you are unsure what I am talking about, take the tip out of the muffler and check it out. This is what I did because I wanted to see exactly what I was going to be removing.

I guess the loudness is a matter of opinion, but I don't think it's very loud at all. It is a noticable difference over stock, but not at all loud and obnoxious. It has a nice, deep, happy tone to it.

Like I stated in my earlier post, if you are going to unplug the airbox, replace the restricted carb insulator and re-jet you will need to open up the exhaust. While I hated to drill the stock tip to the point of no return, I knew that I was't going to use it anymore and if I didn't like the results I would then spend the money on a new tip or exhaust, but my first option would be the free one. Check step 3 in the link. It was basically what I did and am more than happy with the results.

http://www.xr650r.net/nonepa.html

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Some numbers to ponder:

Stock tip at idle (1400 RPM): 79 DB

Stock Tip at 3250 RPM: 87 DB

The drilled stock tip (both innermost baffle and outer pipe drilled out to 2 inches) is 96+ dB at 3250 RPM.

The HRC tip is around 103 dB at 3250 RPM (I didn't test this, another guy did but with the same brand meter and method I used)

FMF Q2 at idle (1400 RPM): 83 DB

FMF Q2 at 3250 RPM: 90-91 DB new, 93 DB after 25 hours on the packing.

The difference between 87 (the stocker) and 91 (FMF Q2) is a lot. But I don't feel the Q2 is too loud. The difference between 91 and 96 is quite a bit to the ear.

Im supprised the HRC tip is 103, for some reason i though anything over 96 was illegal on the road:confused:what is the legal limit?

I was thinking my next mod would be a full exhuast, personally i would go with the Pro Circuit Ti4. And ive heard its 1 of the loudest pipes you can put on.

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When I drilled mine, I used a 2" hole saw and I did it while still on the bike. The only thing left is the spark arrestor screen with the cap on the end of it that sticks inside the muffler. If you are unsure what I am talking about, take the tip out of the muffler and check it out. This is what I did because I wanted to see exactly what I was going to be removing.

I guess the loudness is a matter of opinion, but I don't think it's very loud at all. It is a noticable difference over stock, but not at all loud and obnoxious. It has a nice, deep, happy tone to it.

Like I stated in my earlier post, if you are going to unplug the airbox, replace the restricted carb insulator and re-jet you will need to open up the exhaust. While I hated to drill the stock tip to the point of no return, I knew that I was't going to use it anymore and if I didn't like the results I would then spend the money on a new tip or exhaust, but my first option would be the free one. Check step 3 in the link. It was basically what I did and am more than happy with the results.

http://www.xr650r.net/nonepa.html

jdubb,

I know exactly what you are talking about, I stared at the tip out of the bike and the inside of the pipe for a while and did a lot of drilling and testing - but I brought this up because the pages that talk about uncorking (including the one you reference) stop at what I said earlier was "stage 1" - just drilling the tip. This is where I was confused initially. Most people who talk about being "uncorked", especially the guys who have been around a while, have gone that one step further and drilled that inner baffle (stage 2).

So the way you have it now, yes it is quiet. I didn't measure noise level at that step, but it is probably about the same as the Q2. But still rather plugged up. It is when you go the next step (drilling the innermost baffle) in addition to what you did is when the noise became a factor for me. But that is where the bike REALLY wakes up because you start to approach the flow of the HRC tip. That is when I decided to use the Q2.

I am not saying you should go any futher - I was just trying to pass on what I learned and let you know there was a lot more to be gained. If you are happy, then that is all that matters :busted:

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Ok lets consider how we all (well maybe just me )ride these bikes .

Dare I say ILLEGALY or maybe on the rear tire ,sliding out of corners ,you pick your illegal favorite .

May I offer the value of stealth as a good reason to not be noticed, by the cop sitting around the corner w/windows open. As you boom threw the gears on what must look to be a very ILLEGAL dirt bike to the cop.

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Ok lets consider how we all (well maybe just me )ride these bikes .

Dare I say ILLEGALY or maybe on the rear tire ,sliding out of corners ,you pick your illegal favorite .

May I offer the value of stealth as a good reason to not be noticed, by the cop sitting around the corner w/windows open. As you boom threw the gears on what must look to be a very ILLEGAL dirt bike to the cop.

Ok, let's consider you are incorrect in your assumption.

99.999 percent of my riding is offroad. And I am respectful when I am on the street. I have an ST1300 when I go any further than trail head to trail head.

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jdubb,

I know exactly what you are talking about, I stared at the tip out of the bike and the inside of the pipe for a while and did a lot of drilling and testing - but I brought this up because the pages that talk about uncorking (including the one you reference) stop at what I said earlier was "stage 1" - just drilling the tip. This is where I was confused initially. Most people who talk about being "uncorked", especially the guys who have been around a while, have gone that one step further and drilled that inner baffle (stage 2).

So the way you have it now, yes it is quiet. I didn't measure noise level at that step, but it is probably about the same as the Q2. But still rather plugged up. It is when you go the next step (drilling the innermost baffle) in addition to what you did is when the noise became a factor for me. But that is where the bike REALLY wakes up because you start to approach the flow of the HRC tip. That is when I decided to use the Q2.

I guess, I'm a little confused now???:busted: You said you stopped at 1.25 inches because it was too loud, but I drill mine to 2.00 inches and "the way I have it is quiet?" Unless there is something I can not see there are no baffles in my tip now. There is only a screen (spark arrestor) and a full 2" opening in the end. Are we on the same page here or am I missing something?

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last time i had a sound check on my bike (about a month ago jan 18th for D37) i was at 89db at 3500 rpm this is with the drilled out tip. so it's a stock pipe drilled tip with the spark arrestor still in. uncorked with edelbrock carb

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Ok, let's consider you are incorrect in your assumption.

99.999 percent of my riding is offroad. And I am respectful when I am on the street. I have an ST13000 when I go any further than trail head to trail head.

that 13,000 must go like hell, just kidden

And your rite I'm not the poster child for the DMV ,allthough you may find my picture in the wanted posters .

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