Exhaust Question
 

Has any one on here done any looking into replacing their muffler on either an AC 400 or AC 500 with one used on a small lawn tractor?

I am needing to replace my exhaust AGAIN! and I found a muffler the exact same size off a Sears lawn tractor. I happened to be inthe store and looked at the muffler and thought...hey that might work? I can get one for $85 new while the AC or other aftermarket mufflers are like $150 and up.

I was thinking of buying one and cutting the end off it to see what kind of baffles it has in it to make sure it has the same of similar flow as the stock muffler.

If any one has some info on this I would appreciate it. I am just getting tired of paying $200 for a muffler every 3 years.

Thanks in advance.

SJ

wow....you wear out a muffler in 3 years? What kind of fuel are you burning?

I have never had to replace an aftermarket muffler. I have had to repack some, but have never had one wear out.

My first concern would be whether the lawn tractor muffler would handle the airflow of a 500cc ATV engine....was the lawn tractor engine the same size?

Always remember that when you change your muffler you are changing the way your engine runs,it will usually run hotter which can cause engine damage. I would check with a speed shop or a dealer to make sure that won't happen.

I ride on a salt water beach and no mater how much you wash or what spray you use the muffler rusts up fast. I have not used an aftermarket muffer as they again are like $200 the stock AC mufflers are not cheap either! All it takes after a little rust is to back into a stick in the brush and it punches a hole in the muffler. After a few holes muffler tape just won't seal it anymore and the packing blows out and it gets VERY loud and annoying.

T-cat, do you know of a way to calculate the flow of a muffler? I figured I wold need to change my jetting a little but I figured if it off too much then fuel ecomony would suffer OR I would have no power as flow is being restricted.

I would like to invest in a stainless muffler but my wife insists on saving money for a new Prowler. Guess I will have to take her advice. :)

SJ

Normally you would check your plugs after a short WOT run,now i'm not sure if the same procedure will work for a 4 stroke,the other method is for a 2 stroke. The plug will still give you a fairly accurate reading. You will be looking for a nice brown colour. It will also depend on how much difference in size inside, not outside the muffler, hope this helps.

Well I went ahead and bought one and I am going to cut it open on the end the exhaust comes out and have a look at how many baffles there are and how large the air passages through the baffles are. I am also going to do the same to my rusted stock muffler and I am hoping I can make a comparison on area of opennings for air flow and such. The O.D. dimensions are 1/4 inch shorter and 1/8 inch in diameter difference than stock AC muffler. Inlet and outlet ports are smae size. Plus I got this thing for $42!

If all looks good I will install it and give it a WOT test and check my plug color. I wilal let you know what I find.

SJ

I spoke with my mechanic about your situation and he figures you will be safe with your idea. He also says you will probably notice a slight difference in performance. I am anxious to hear how it works,lookin forward to hearing from you.

Well I have discovered that there are more baffles in the new muffler than in the stock one with smaller holes than stock as well. I am going to see if I can remove a few of them and make the remaining holes larger so flow is not too restricted as to limit power.

SJ