Gx390 exhaust

[BlakeP]

Hello I’m doing a decent block not a big block swap lol but I’m wondering if anyone’s done a gx390 and what did you do as far as the exhaust goes. Thank you in advance! Love the feedback!

[raydhd]

There is a ton of info on my "clone exhaust" thread from a variety of solutions used by people installing the 390-460 honda and clone engines.

[slonomo]

You can buy a pipe from one of our sponsors, or you can make your own with a kit. Vegas Carts has a nice thick walled pipe kit, not too expensive. Mufflers are the trick. There are all kinds of options, but it seems that space is the defining factor. I like the universal tractor muffler I used on my cart, it sounded pretty good, quiet enough that it didn't bother anyone.

[BIKERMIKEYBLACK]

I just put that same 22022 walker tractor muffler on my vanguard and it sounds great sorta loud but not too bad on the other hand it was the same muffler that was included with the Vegas 460 engine and most people say it’s too loud so I guess it depends on the engine, compression,cam etc how loud it is

[slonomo]

Not everyone's idea of "loud" is the same. If you compare with a stock golf cart, yes, anything is going to sound loud. If you compare with open pipe, that's another story

I have a decibel meter. I measure at 5 feet, 10 feet, and 20 feet. Under 90 decibels would be considered quiet IMO. Over 100 is loud.

Sound quality makes a difference. A fully welded exhaust will sound better than a clamped exhaust due to tiny leaks that make the exhaust pop. Also, larger diameter pipe and muffler will make a deeper tone, which may sound better to most. Straight through mufflers will be louder than mufflers with "S" turns inside. Glass packed mufflers make a raspy sound.

I've tried no less than 10 different muffler's on my cart over the years. The one I ended up with is in the picture. You can find this muffler at Tractor Supply, Rural King, and most IH, JD, and Kubota dealers. It's just a universal muffler. I really like the sound. The wife also likes the "quietness" of it.

Specs:

Inlet Length (A): 2"
Inlet I.D. (B): 1-11/16"
Shell Length (C): 15-1/2"
Outlet Length (D): 4"
Outlet O.D. (E): 1-3/4"
O/A Length (F): 20"
Weight in LBS: 5

[slonomo]

For exhaust pipes, look for one that has a 1 3/4" or 1 1/2" diameter with thick walled construction. The larger diameter will help the sound tone. The thicker walls will help insulate the heat, help it to sound quieter, and it will weld better.

My pick is Vegas Carts. They will sell you an unfinished builder kit that comes with the pipe in multiple sections with bends etc, comes with nice thick flanges. It can be cut easily with a bandsaw or even a recip. Welding with a standard 120v flux core welder is super easy. Or, just tack it together and take it to a muffler shop to be fully welded. Just make sure they spread the welds out to reduce heat warping.

Vegas Carts Kit:

this one is for a V twin, but they will make a kit for your clone.
https://vegascarts.com/collections/y...12399520448556

this one is fully welded for an EZGO with a clone engine
https://vegascarts.com/collections/e...wap-no-muffler

[BIKERMIKEYBLACK]

SLO wat Brand is that muffler it’s different from mine I ordered a walker and got a Stanley which is not as good but seem to what they’re doing now subbing the Stanley for the walker

[slonomo]

Yeah mine is a walker. I've seen where they are using the Stanley. Seems to be the same. MAREMONT is the parent company of Walker, wonder if they make Stanley too?

[BIKERMIKEYBLACK]

I’m thinking they must own them too anyway Stanley’s a much better muffler

[bswisher]

I just put a stock gx390 in my hyundai cart and left the stock honda muffler on it.. Way quieter than the 420 clone I had in it before. Going down the road I can hear the tires more than the exhaust.