Hawk Stock Muffler with Pro Circuit Quiet Insert

pcspecialist · 07-13-2016, 05:21 PM

I had already decatitated the exhaust and drilled holes in the muffler, but, didn't notice much of a power gain so I decided to increase the opening on the end of the muffler by replacing the stock insert with a Pro Circuit one (which is a bolt in replacement). My top speed only went from 62MPH to 64MPH, but, mid-range power has significantly improved..... I get to 62MPH much quicker. The engine isn't fully broken in yet so hopefully I'll get even faster speeds in the future.

Drilled holes inside muffler with a long bit I have for running cables to reduce back pressure. The plate inside the muffler is further away than the zoom lens make it look like. Probably too many holes, wish I had used the larger insert instead of stock one when I was test driving between hole drilling (there are more than you see in the picture).

With the insert installed

This is the insert I purchased, but, what I received does not protrude into the muffler so I'm going to find something different as I want to be able to hose-clamp a screen on the inside.
http://www.amazon.com/gp/product/B001654JK0

Code:

don't know why it keeps changing it to amazon.ca (where you can't even get it) here's the url you need: http://www.amazon.com/gp/product/B001654JK0

*Deleted the second option as it isn't an option*

You can follow everything I've done to my Hawk here (will eventually add the insert mod once I've narrowed down the best insert):
http://www.chinariders.net/showthread.php?t=16636

Weldangrind · 07-14-2016, 11:48 AM

That's cool! How did you determine that the Pro Circuit tip would fit the stock muffler?

pcspecialist · 07-14-2016, 11:53 AM

I measured the stock insert disc size, found it was 4", did a search for 4" muffler inserts and found Pro Circuits have both 3.5" and 4" canisters so I figured their inserts for the 4" canister would work. I just wish the one I got protruded some into the muffler so I could hose clamp a screen to it.

I love the length and bend outside the muffler. Even though it is louder than stock, it directs the sound such that it is quieter for the person seated on the bike (I think, I may have to swap between the two a few times).

Weldangrind · 07-14-2016, 12:32 PM

When you next remove it, please show us a pic of the part that inserts into the muffler.

pcspecialist · 07-14-2016, 05:12 PM

Weird, somehow this response ended up in the wrong thread.
It looks like this, the other side is just a flat 4" disc with a hole in it.
https://www.denniskirk.com/433882.sku

Weldangrind · 07-15-2016, 11:16 AM

A person could tack-weld a stainless tube on the muffler side, allowing installation of screen. The exterior portion could also be polished for a little bling (which also makes it much easier to clean).

pcspecialist · 07-15-2016, 11:12 PM

I spent some time riding it today, and, am definitely noticing a significant increase in power. Once I discovered it doesn't fall flat on it's face past 6K RPMs like it used to, I'm shifting at 8K RPM (when trying to get up to speed quickly) and can really feel it pull with EVERY shift. I could do 55MPH comfortably all day long, even sustaining 60MPH is no problem at all if not fighting a wind.

Weldangrind · 07-16-2016, 10:37 AM

I'm glad you're finding the bit of extra power that's hiding in places like the carb and exhaust.

2LZ · 07-16-2016, 01:46 PM

Quote:

Originally Posted by pcspecialist

I spent some time riding it today, and, am definitely noticing a significant increase in power. Once I discovered it doesn't fall flat on it's face past 6K RPMs like it used to, I'm shifting at 8K RPM (when trying to get up to speed quickly) and can really feel it pull with EVERY shift. I could do 55MPH comfortably all day long, even sustaining 60MPH is no problem at all if not fighting a wind.

Excellent news! How many miles do you have on it now? Mrs. 2LZ TT is acting like a typical CG motor, so far. There's been substantial increases in mid range pull between 350-500 miles, even in stock form. I can't wait to start the mods.

pcspecialist · 07-18-2016, 07:57 PM

Finally got the other insert. The exit diameter is 1.5", but, the part sticking inside the muffler is just barely larger than stock. Pretty useless. I'm going to stick with the first one I got and eventually get around to installing a screen, somehow.

Weldangrind · 07-19-2016, 11:37 AM

May we see a pic of the useless insert? Both sides?

07-13-2016, 05:21 PM	#1
pcspecialist Join Date: May 2016 Posts: 583	Hawk Stock Muffler with Pro Circuit Quiet Insert I had already decatitated the exhaust and drilled holes in the muffler, but, didn't notice much of a power gain so I decided to increase the opening on the end of the muffler by replacing the stock insert with a Pro Circuit one (which is a bolt in replacement). My top speed only went from 62MPH to 64MPH, but, mid-range power has significantly improved..... I get to 62MPH much quicker. The engine isn't fully broken in yet so hopefully I'll get even faster speeds in the future. Drilled holes inside muffler with a long bit I have for running cables to reduce back pressure. The plate inside the muffler is further away than the zoom lens make it look like. Probably too many holes, wish I had used the larger insert instead of stock one when I was test driving between hole drilling (there are more than you see in the picture). With the insert installed This is the insert I purchased, but, what I received does not protrude into the muffler so I'm going to find something different as I want to be able to hose-clamp a screen on the inside. http://www.amazon.com/gp/product/B001654JK0 Code: don't know why it keeps changing it to amazon.ca (where you can't even get it) here's the url you need: http://www.amazon.com/gp/product/B001654JK0 Deleted the second option as it isn't an option You can follow everything I've done to my Hawk here (will eventually add the insert mod once I've narrowed down the best insert): http://www.chinariders.net/showthread.php?t=16636 Last edited by pcspecialist; 07-18-2016 at 07:59 PM.
	2

07-14-2016, 11:48 AM	#2
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	That's cool! How did you determine that the Pro Circuit tip would fit the stock muffler? __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

07-14-2016, 12:32 PM	#4
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	When you next remove it, please show us a pic of the part that inserts into the muffler. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	1

07-15-2016, 11:16 AM	#6
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	A person could tack-weld a stainless tube on the muffler side, allowing installation of screen. The exterior portion could also be polished for a little bling (which also makes it much easier to clean). __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	1

07-16-2016, 10:37 AM	#8
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I'm glad you're finding the bit of extra power that's hiding in places like the carb and exhaust. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

07-14-2016, 11:53 AM	#3
pcspecialist Join Date: May 2016 Posts: 583	I measured the stock insert disc size, found it was 4", did a search for 4" muffler inserts and found Pro Circuits have both 3.5" and 4" canisters so I figured their inserts for the 4" canister would work. I just wish the one I got protruded some into the muffler so I could hose clamp a screen to it. I love the length and bend outside the muffler. Even though it is louder than stock, it directs the sound such that it is quieter for the person seated on the bike (I think, I may have to swap between the two a few times).
	0

07-14-2016, 05:12 PM	#5
pcspecialist Join Date: May 2016 Posts: 583	Weird, somehow this response ended up in the wrong thread. It looks like this, the other side is just a flat 4" disc with a hole in it. https://www.denniskirk.com/433882.sku
	0

07-15-2016, 11:12 PM	#7
pcspecialist Join Date: May 2016 Posts: 583	I spent some time riding it today, and, am definitely noticing a significant increase in power. Once I discovered it doesn't fall flat on it's face past 6K RPMs like it used to, I'm shifting at 8K RPM (when trying to get up to speed quickly) and can really feel it pull with EVERY shift. I could do 55MPH comfortably all day long, even sustaining 60MPH is no problem at all if not fighting a wind.
	1

07-18-2016, 07:57 PM	#10
pcspecialist Join Date: May 2016 Posts: 583	Finally got the other insert. The exit diameter is 1.5", but, the part sticking inside the muffler is just barely larger than stock. Pretty useless. I'm going to stick with the first one I got and eventually get around to installing a screen, somehow. Last edited by pcspecialist; 07-19-2016 at 12:43 AM.
	1

07-19-2016, 11:37 AM	#11
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	May we see a pic of the useless insert? Both sides? __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0