Slip on exhaust?

[Guest]

If I can find a slip on exhaust that will fit my 1980 gs1000g, would it hurt my performance any? Mine have pretty large rust holes in the factory exhaust, but otherwise they still look good. I would be cutting them off right after the 4-into-2 "Y" and mounting the new too there. Or is this just a horrible idea? I don't have a lot of knowledge about these bikes specifically.

[hjfisk]

You can do it but depending on how open of a can you use you may have to reject. I put Two brothers cans from a Hayabusa on my 78 and had to go up 4 jet sizes

[Nessism]

The mufflers are welded to the head pipes so you gotta plan where you want to cut and find some mufflers of the appropriate size. I've seen some threads over the years here where guys installed Dunstall knockoff mufflers on their stock head pipes with decent results but I'm not sure about what's involved to make the transplant.

[Rob S.]

I'm always slipping on exhausts. Darn kids leaving their mufflers all over the driveway, I get home from work, get out of the car, don't see 'em, WHAM!! Flat on my back.

Darn kids.

[Chuck78]

I installed some of the Emgo Dunstall style megaphone mufflers on the wife's gs550. it required welding a short piece tubing onto the factory pipe where it goes from 2 until 1. I had to adjust the angle with the muffler bolted on to the rear mounts, and grind the piece at the correct angle, and then weld it with the muffler bolted in on both ends. they sound awesome, but not exactly quiet. Very very excellent tone. They could use a little more packing. slightly drone on the highway but very very good sounding under acceleration, one of my favorites actually. Long straight through glasspack baffle. The length adds to the tone.

I believe MAC makes slip ons for some models of GS's.
you will likely have to put larger jets in your mains, and possibly shim your needle slightly, or just get a Dynojet kit and put their smallest main jet in. if that is too rich, at wide open throttle high RPM, then add a K&N air filter to your air box and the Dynojet kit should make the bike perform better then.

[Chuck78]

I see you are in Lowell Ohio. you have some of the best roads in the state just east of you! I love to hit 530 out of Lowell, then I believe it is 821 South to connect to Dalzell Road and Germantown Road. excellent Loop. Wayne National Forest. To 565, 260, and 537... I like it slightly better westbound& the uphill lane (riding westbound downhill with the hill incline to your right)westbound @ the Lamping Homestead Recreation Area was in good shape where the uphill eastbound climb lane with the steep downhill drop-off to the right was not in the best of shape @ Labor Day weekend. I really like it west bound for the added big hill climbs throughout, especially 537@26 & the eastern end of 530 just heading out of that town. getting some serious lean angle on those 15 mph steep hill climb turns thrills me like nothing else

I'm a total fanatic for the twistiest of roads in remote forested areas, and that run through those several roads is one of my absolute top favorites in Ohio.

You sound like more of a casual cruiser, so you probably like my more casual twisty favorite OH-78 just north of you 25 minutes that just got pretty much completely repaved this past riding season. it wasn't even in bad shape before the paving! Half of Dalzell got repaved also.
536 is not slated for repaving until next year, and is in bad shape. Fracking trucks. Hard on the pavement. That road has several surprise turns that wreck lots of riders. The "Ohio Dragon." maybe I am rehashing twisty road tips that you already know of course.

Best of luck with your project and happy riding. If you weld on anything to attach universal mufflers, make sure you use good exhaust paint, like POR- 20. That is one of the few that actually lasts several seasons.

[shameless]

I see you are in Lowell Ohio. you have some of the best roads in the state just east of you! I love to hit 530 out of Lowell, then I believe it is 821 South to connect to Dalzell Road and Germantown Road. excellent Loop. Wayne National Forest. To 565, 260, and 537... I like it slightly better westbound& the uphill lane (riding westbound downhill with the hill incline to your right)westbound @ the Lamping Homestead Recreation Area was in good shape where the uphill eastbound climb lane with the steep downhill drop-off to the right was not in the best of shape @ Labor Day weekend. I really like it west bound for the added big hill climbs throughout, especially 537@26 & the eastern end of 530 just heading out of that town. getting some serious lean angle on those 15 mph steep hill climb turns thrills me like nothing else

I'm a total fanatic for the twistiest of roads in remote forested areas, and that run through those several roads is one of my absolute top favorites in Ohio.

You sound like more of a casual cruiser, so you probably like my more casual twisty favorite OH-78 just north of you 25 minutes that just got pretty much completely repaved this past riding season. it wasn't even in bad shape before the paving! Half of Dalzell got repaved also.
536 is not slated for repaving until next year, and is in bad shape. Fracking trucks. Hard on the pavement. That road has several surprise turns that wreck lots of riders. The "Ohio Dragon." maybe I am rehashing twisty road tips that you already know of course.

Best of luck with your project and happy riding. If you weld on anything to attach universal mufflers, make sure you use good exhaust paint, like POR- 20. That is one of the few that actually lasts several seasons.

I grew up just off of 78/83, and 339 between beverly and Macksburg. driving on 530, 676, 26, and 555. 78 is a nice cruising road, except that one hill coming out of Sharon going towards Meigs, its a little nasty if you aren't expecting it. lol

[shameless]

So I need to start by getting the exhaust first, then see if I need to mess with the carbs?

[shameless]

Is that right?

[Who Dat?]

Yes, your carb jetting will depend on how much air is going through the carbs.

The stock exhaust on a GS is really rather free-flowing, so swapping out for a header or, in your case, some mufflers that might flow a bit better, might change the tone, but not the air flow capacity. In stock configuration, the airbox is a major restriction, which is why changing the exhaust doesn't matter much. If you go to individual pod filters, you will allow a LOT more air through the carbs and will have to jet accordingly.

You might have to add a couple jet sizes for an exhaust change, but up to 8 sizes or so for changing to pods. It's not just changing the mains, you also need to adjust the needle. The stock needle has no adjustment built in, so changes to height have to be made by changing the thickness of the stock spacer. However, if you get into full "pods and pipe" mode, raising the needle isn't enough, you need needles with a different taper. That's where the expense of a Dynojet kit is worth it.