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HMF Quiet Core Insert
HMF Quiet Core Insert

$31.95 $34.95
9% Off - Save $3.00

Select your ATV to see if this exhaust fits
Description See Also: 8 Reviews 26 Questions Fitment Part Numbers
Item #HMF000G

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8 Reviews
4.4 out of 5 stars
5 Star   5 4 Star   1 3 Star   2 2 Star   0 1 Star   0
All Reviews
hadtohaveit Verified Purchaser
1 year ago Ohio
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Perfect Solution for LOUD pipe

Bought a used 2012 Brute Force ATV with the aftermarket HMF exhaust.
Pipe was way too loud to run around the neighborhood, this Quiet Core was the perfect answer and still has great sound and did NOT impede performance.

Hunter Verified Purchaser
1 year 4 months ago Elsa Texas
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Awesome equipment

Bought item and it works great no issues with it thanks.

Matty Verified Purchaser
Over 3 years ago Greenville, NC, USA
Good Value Solution

WARNING... If you are considering a new slip on tail pipe for your ATV, be warned that the HMF muffler sounds like a straight through system with NO baffling!!
My options were to junk the pipe, or to purchase this low cost, easy to install solution.
The pipe is still pretty loud, however, much easier to live with!!

JB72 Verified Purchaser
Over 3 years ago
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5

Great product. Easy to install.

Over 3 years ago Alabama
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5

I dont have a dB reader/gauge so I can not give you the exact dB before and after instullation, but It made a noticable difference. I rejetted carb after instullation and did not notice a power loss on high or low end. Keep in mind you DO need a gasket or it will rattle. It changed the tone of the exhaust aswell but I like it better now than I did before.

MrNacho Verified Purchaser
Over 5 years ago Puyallup, WA, USA
Durability4/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Insert used on trx450er with HMF Performance Seri

Ordered this with HMF Performance Series pipe on my wife's 2006 trx 450er and it performed killer. We got Sound tested by the U.S. Forest Rangers last week at Coos Bay bay. the pipe with the power core insert registered 85db and the limit was 93db at the time.
the quad performed really well with this set up after being jetted with the dyno jet kit. it gave real strong performance over stock.

Over 8 years ago Montana
Great product

Just what I was hoping for,quiet for the mountains,easy to pull if need be

Over 10 years ago Pasco, WA
It's quiet

I was on the fence with this purchase, but decided to go for it so I would have it in case I went somewhere with noise regs. In short, I could definitely tell the difference on my 660 Raptor. W/O the quiet core, the Raptor took off like a rocket. With the quiet core, it's still better than stock, but much more sedated. The product is very well made and installs in about 5 minutes. I'd give it more stars if it didn't suck as much power away. Good value for the money.

26 Questions
Answered:   25
Not Yet:   1
Q: I just bought a used 2013 Polaris RZR 570 EFI, all stock. I honestly have no clue what exhaust it has.. Will this fit the stock exhaust for my UTV? Thanks.
Over 7 months ago
Top 25
Over 7 months ago
A: The quiet core is specifically for HMF mufflers, it will not work on the stock exhaust.
Q: I bought this Quiet Core Insert and the Spark Arrestor Screen but can't find install instructions anywhere online for Kawasaki Mule 550. Your site shows it will fit but HOW and where?
Over 7 months ago
Top 25
Over 7 months ago
A: This quiet core fits the following exhausts,
*Peformance Series.
*Swamp and Swamp XL Series.
*Penland Series (Torque Range Modifier removed).
*Signature X Series.
If you do not currently have one of the models than it will not fit. Please call in to let one of our representatives assist you.
Q: I have a 2001 Honda 400ex with a White Brothers exhaust, will this insert fit my exhaust? 
Over 7 months ago
Top 10
Over 7 months ago
A: The HMF Quiet Core Insert is intended to fit the HMF mufflers. It probably won't fit your White Brothers muffler.
Q: Have 2017 Kawasaki Mule SX,XC and very disappointed in loudness of vehicle, especially when ascending hills. Had concluded problem is due to simply engine noise and NOT from muffler. Will your device help? Alternate: "noise blanket" above engine ?
Over 8 months ago
Q: I have a 2006 Yamaha 660 Grizzly that's too loud for hunting. I plan to remove and clean the stock spark arrestor. Can I add your Quiet Core insert to a) work in tandem with the existing spark arrestor or b) use the Quiet Core Insert by itself?
Over 11 months ago
Dan Gearhead
Top 25
Over 11 months ago
A: Unless you have any of these following HMF exhaust, this will not fit your bike. Peformance Series.
Swamp and Swamp XL Series, Penland Series (Torque Range Modifier removed). Signature X Series.
Q: I have a kfx 700 with the HMF aftermarket exhaust , this bike is extremely loud , will this part silence the bike and operate correctly ?
1 year 2 months ago
Top 25
1 year 2 months ago
A: Without knowing the year of your bike, i am unable to find out that information
Q: I have a 2007 660 Rhino Special Edition factory exhaust. I need to extremely reduce the exhaust noise. What is your suggestion?  
1 year 4 months ago
Top 10
1 year 4 months ago
A: This will quiet down your engine noise approx. 8-10db. This would be a great way to reduce your noise.
Q: My bike is EFI where the computer reset itself if I put the silencer in
1 year 8 months ago
2008 brute force 750 4x4
Top 1
1 year 8 months ago
A: No. You would need to have your ECU flashed at a dealership (if possible for your model), or install a fuel tuner module.
Q: Would I have to re-jet or adjust fuel screw? And if so, how do I know when it is adjusted properly?
2 years 8 months ago
I have a 04 dvx 400 with a performance series, just looking to quiet it down a little. What I'm wondering is if I would have to re-jet, if so what sizes I would need, or if it comes to adjusting the fuel screw as mentioned in one of the previous questions, how would I know it is correctly adjusted? Thanks for your time
HMF Engineering
2 years 8 months ago
A: If you're looking to make your exhaust quieter, HMF has a Quiet Core insert that can reduce the sound 2-4dB.

For the proper jetting, HMF recommends:

Recommended Tuning
Slip On - 145 Mikuni Small Main Jet
Full System - 150 Mikuni Small Main Jet

Removing the Air Box Lid or aftermarket filter may require 170-175 Mikuni Small Main Jet

HMF Basic Jet Kit Includes
140, 145, 150, 155, 165, 170, 175 Mikuni Small Main Jet
Q: This product has a spark arrestor built-in or a spark arrestor is still needed
2 years 10 months ago
HMF Engineering
2 years 10 months ago
A: All HMF Exhaust systems come with a USFS Approved Spark Arrestor.
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See Fitments
# Part Numbers
Product Variant Manufacturer Part #
HMF Quiet Core Insert 6946006