GT380 Exhaust variants

[angus]

Good afternoon

Currently restoring a 1976 gt380 A with a 3 into 1 of unknown origin on it. Is there any difference in the factory 4 pipe exhaust systems fitted to the J,K,L,M,A and B bikes, or are they all interchangeable

Cheers

Angus

[jabcb]

Suzuki modified the exhaust for better cornering clearance. The muffler mount on the frame was moved when they did the redesign, so the frames are also different.
J/K have the early exhaust & frame. L & later have the modified exhaust & frame.

I have a GT380 with an early frame, and a late motor + late expansion chambers. You can make it work but its a PITA to do.

[angus]

thanks for the answer appreciated

[Craig380]

You can fit the J/K exhausts on later frames fairly easily, you just need to make a small adapter plate to bridge the gap between the mounting point by the pillion footrests and brackets on the pipes.

But the J/K exhausts are not as upswept as the later type, so they do hang lower.

Unless you're mad keen to have the factory system, I would recommend fitting chambers. Many used standard exhaust systems are in a bad state internally - the baffle plates break loose, the mesh sound-dampening breaks loose .... you can open them up, repair them and get them rechromed but that costs a LOT, way more than a set of new chambers.

[angus]

Thanks for your input everybody. The bike has a 3 into 1 which is starting to show its age a little. My initial thought was to bring the bike back to stock, but thinking about it, the old adage of if it isn't broken don't fix it springs to mind, so out with the polishing mop and elbow grease.

[Craig380]

If yours is a UK bike it's probably a Piper 3-1 that's fitted. I had one on mine for a year or so. They sound amazing but they stop the bike revving past 7,000 - it's like hitting a rev limiter. So it means your real-world top speed on the road is about 85mph.

If you've got the factory airbox and filter still, you don't need to rejet, it runs a little richer with the 3-1 fitted compared to the standard pipes.

My favourite moment when I had the Piper on my 380 was when I stopped at the Cat & Fiddle pub one sunny Sunday. The car park was full of the latest flash sportsbikes, but when I fired up the bike to leave, EVERYONE stopped and looked around in a "what is THAT" way