Automotive muffler for maxiv

[rcn11thacr]

I really want my 07 max iv to be much quieter thank it currently is. Since its an 07, chances are the muffler is not worn out and a visual inspection shows no cracks, etc... I am looking at replacing the factory muffler on my 27 hp kaw with a small muffler off a 4banger. Has anyone had any experience with this or seen any lawn mower type motors with quieter automotice mufflers? Reasoning behind this endevor is i'm an old army scout. I've had so much range time shooting and eod (explosives) stuff that i'm damn near deaf as a post. I'm only 41 and i'd like to save what hearing i have left for when my eye sight is gone .
I've suppressed all of my guns and now its time to "suppress" my max. My 6 year old can sit in my lap while we drive, carry on a conversation with me (mere inches away from him) and i cant hear 90% + of his words at anything above half throttle. I remind him to constantly turn his head and speak into my ear, even then i have an almost impossible time understanding what he is saying unless i drop to an idle.

[Dozerlarry]

don't see why it wouldn't work but it seems like the muffler made for the Max would be the best bet. They're noisy beasts anyway you look at it, all the chains and pulleys turning plus the tranny doesn't help. Did you think of the intercom headsets the motorcycle people wear? I believe the Harleys now are louder than my old M60 tank was. They fly past me on the highway all the time wearing them. Probably some hearing protection just wearing them.

[rcn11thacr]

Well, i know from first hand experience that a M60 tank is one VERY loud tank (lol, good analagy to the harley). The the head sets are certainly an idea. One main problem i see with them is their cost. Very expensive (yes, i know...so are hearing aids). I will not rule that idea out but ill admit i'd much rather get as much of the sound quieter than it currently is, and divert what i cannot get rid of. I'm currently building a mold that i can use to mold a replacement floor (2 piece unit) that will hold much closer than the factory units. This should do a few things at once; (a) fill the gaps sound gets out of from the tranny and chains, (b) Give a good surface much more worth the effort to take the time and lay dynamat to its bottom side (c) it gives me the chance to make rubber boots over the latterals and other items that have to stick above the floor boards. (d) as an extra to building the new floor i have the added bonus that the new floor will eleminate virtuall all of the dirt, leaves, and sticks that enter the max, ever having the chance for them to drop down into the tub. After the effort to build the new floor and add the automotive muffler, i'll add dynomat to the engine cowling to see how much more sound i can divert towards the back of the rig. Any ideas are much appreciated...

[Dozerlarry]

great idea on the floorboards! I'd actually thought of getting some aluminum sheet and doing what you're talking about. Fiberglass would probably be better but I don't have any experience at molding the stuff. If you do all this I think you will have really cut the noise level a lot. Probably could sell a few of the upgraded floorboards also. I'm working out from Titusville here for a week or two. I was going to see about coming by and see your rig when I go back home if it isn't real late at night when I come through.

[Tomo]

HI
Noise reduction in the case of a max is an interesting subject . Similar circumstance is an air cooled generator.
After what I have read the engine cover should be sprayed first inside with a product called stone guard [auto body chip guard product up to 1/8 thick ]. This stops the panel resonating to much and transmitting noise. Apply a fire proof foam wedge shape cone foam material [sound proofing] . The wedge foam is the best shape for absorbtion and dissipation . IT IS ONLY ONE PART OF THE SOLUTION. The key is to have dense/heavy and thick barriers . Isolation does come into it but not for this application [impractical ]

Thick heavy floors will help .

The muffler custom
1/ as large as u can physically make it ,oval muffler is easiest
2/ Double outer skin muffler 1.6 mm layers x2 OEM WILL ONLY BE 1.0 MM THICK
3/ heat shield material between each layer
4/ internal baffles plates 1/8 thick
5/ all stainless
6/ twice the weight of original
1---1 1/4 primaries
1 1/2 outlet is fine
I have used this type of muffler as a replacement on 25hp kohler works great .
DEEP sound with reduced noise and heat [the original was splitting and melting inside ]

tomo

Ps u can make a chambered muffler eg triple pass or
a long round muffler with both primaries entering at one end [1st chamber ] going into one 1 1/2 perforated tube ,12 inches at least long surrounded by fibre glass weave [cherry bomb ] The trick is to make the outer diameter big so the fglass can absorbe the sound . A spark arrestor is always a good idea .

[Normable1973]

I have the kohler command pro 27hp and the muffler I have is very quiet. People are always saying it's so quiet

[814cannob]

I've thought about using heat & sound insulation on the inside of the motor cover available on E-bay. I like to sneak up to my hunting area with out spooking everything. The other problem is where to vent the heat from the motor too. Automotive Heat Shield Sound Insulation Barrier 42x48 | eBay

[phabib]

There is some foam that has mass loaded vinyl that is supposed to do a very good job. Its sold to quiet down generators or other loud stuff. I think the first thing is to seal the enclosure as much as possible. Have your openings for air/heat at the rear, seal the compartment, then cover the barrier between you and the noise with the mass loaded vinyl/foam sheets.

I've had pretty good results quieting generators with a bigger auto muffler, but it only addresses one of the sources of noise in a small engine. A lot of the noise from the internal parts, not just from the exhaust.

[Dano1877]

I have a Briggs V twin 20 HP in one of my max II's. It has an external factory muffler and also another right of the engine inside it's very quiet!! I'd post a pic but not sure how from my phone. This site needs to upgrade that capability

[rcn11thacr]

I have the kohler command pro 27hp and the muffler I have is very quiet. People are always saying it's so quiet

Do you know what type muffler that is?