GS750 with Kirker, way to loud

[Qckslvr]

The 78 GS750 I bought has a rusty kirker 4-1 system on it that has been JB welded back together. The Kirker seems to hang pretty low and has some holes worn through the pipes. These are easy to fix, I am just going to weld in some new mandrel bent pipe. But that is not the issue or question.

The system is loud, obnoxiously loud. The collector on the system is 3.5"s, and the muffler being a megaphone just gets bigger. The bike also has no torque, which I know is due to no back pressure in the system. So I was searching ebay for a muffler when I came across the Dunstall replicas with reverse cone and removable, re packable baffles. These are 1 3/4" inlet diameter. So I was thinking a 4 to 5 inch long tapered from 3.5 to 1 3/4 cone. My question is, will this be to much restriction? I know that my GSXR 1000 and 1100 did not have huge pipes, I seem to recall something it the 2" range.

Any thoughts on this will be much appreciated. And unfortunately I do not have a stock system to compare to or tune with.

Thanks

 

[steve murdoch]

Is there a baffle inside the muffler?
After you weld some patches on the holes you could repack the muffler.
A couple wraps of something like this would be a cheap temporary solution.
http://cgi.ebay.com/ebaymotors/MSR-...2996757QQptZMotorcyclesQ5fPartsQ5fAccessories

 

[Qckslvr]

Is there a baffle inside the muffler?
After you weld some patches on the holes you could repack the muffler.
A couple wraps of something like this would be a cheap temporary solution.
http://cgi.ebay.com/ebaymotors/MSR-...2996757QQptZMotorcyclesQ5fPartsQ5fAccessories

The JB weld beleave it or not is not leaking LOL. But it is hideous and ugly, I am going to header wrap the system though to hide the patch job. The Kirker though does not have a removeable baffle. Or inventory guy was a bike mechanic for 25 years and said something about it being a big mouth system. The tip of the megaphone is 4" with the inside of the baffle at just about 3"

 

[Guest]

I have a Kerker like that and put a Vance and Hines baffle in it.

 

[Guest]

That looks like the same Kerker pipe that is on my GS1000 and it has a removable baffle. look for a screw near the end of the muffler