1978 GS750 exhaust

[Chuck78]

Not to mention that the Mac isn't worth $500 and the Delkevic is a better exhaust and is cheaper.

Do you mean Vance & Hines? The $280-300 V&H GS750 pipe now I only see for $499. Perhaps discontinued?

The MAC on the other hand is certainly worth the $252 shipped to my door (definitely not $499!), & The $335 & $355 Delkevic's are the quality of a $500 pipe...

[aclaytonb]

Got a MAC on my 550. You get what you pay for. Sounds tinny and cheap - never seen one that didnt rust on year one. Had to pull the baffle, drill it, pack it, and re-rivet it in place. In hindsight, I could have just bought the performace baffle.

+1 on delkevic.

[dorkburger]

Regarding the Mac. Back in the day, my 1100e came to me with one - canister muffler type. As a test I took out the baffle with its quarter sized openings and immediately noticed a seat of the pants power increase, and as noted it didn't sound particularly good. I made a straight thru type baffle with miscellaneous exhexhaust tube, reducers, etc, and drilled my new insert full of holes and added a small turnout to direct the noise down and away from the bike. Sound level was still neighborhood friendly, but it ran better, and ended up with such a cool unique sound.....
Agreed on the quality not being great, but it lasted thru the 5-6 years I rode it, and that was back when I actually had time to ride a lot, typically 5-6K miles per season in all weather.

[Chuck78]

FYI in my experience, with basically all painted headers, the paint never seems to last very long unless it is ceramic coated or has some sort of hi-temp powder coating. Painted headers never last long before needing repainted...

Glen, I also fabricated my own DIY performance baffle for the MAC pipe that came on my bike, as the stock MAC sounded basically like a stock exhaust but just slightly louder. Not my style.

[aclaytonb]

Mine was chrome and starting to rust around the header collars the first month. Granted, got it cheap but still... Thin single walled chrome, IIRC.

[dorkburger]

Chuck, mine looked pretty similar.

[mavrik]

Again guys thanks for all your input... I will let you know which one I end up buying and how it fits... maybe even a few pics...

[miguel]

Also, if you want the throaty aggressive sound, Mac sell a performance baffle that slips right into that muffler can
I think it's probably around $55 or so

AND... Here is the deluxe model...

https://www.ebay.com/itm/172301586321

$335 shipped, all stainless. The megaphone version has a more aggressive tone, but the muffler section is much more bulky, and it is about $359 shipped. Both links have an install picture so you can see what they look like. Same style of baffle, but the megaphone is much larger inside diameter. Despite being a smaller baffle opening, the straight upswept road race style pipe is still pretty aggressive sounding.
https://www.ebay.com/itm/172301588353

Hey everyone! greetings from portugal...

so as I was reading this thread it caught my atention due to the fact that I am considering buying a Delkevic exhaust to my 79' GS850. One thing, they site that no rejetting is necessary, but the fact is I am still running stock 4-2 headers and marving mufllers ( wich might I say top quality! ). So will it need to be rejetted?

[miguel]

The Delkevic stainless steel pipes are incredible quality. I have one on my 750.

Marving makes a killer pipe also, but Italian, so import costs and waits are not quick or cheap. Predator and Motad I think are 2 others from Europe.

There are Jardine and Bassani NOS pipes on ebay but pricier than v&h or mac new

If you are ambitious at all and wanting to wrench on it, it won't be a $500 bike for a long if you keep making little improvements to it over time, and it will be a much better bike afterwards.

Hey again FYI,

I recently emailed Marving Inc askin about their exhaust systems, because for the GS750/850 they only sell the ones I have, 4-2 end mufflers. So I asked them if the 4-1 racing exhaust ( wich is beautiful ) for the GS1000 would fit and they said no.

[Chuck78]

Hey again FYI,

I recently emailed Marving Inc askin about their exhaust systems, because for the GS750/850 they only sell the ones I have, 4-2 end mufflers. So I asked them if the 4-1 racing exhaust ( wich is beautiful ) for the GS1000 would fit and they said no.

They will fit, but you have to fabricate your own exhaust hanger bracket, and the pipe hangs lower than it should. Their website is misleading because it says something to the effect that they make the 4-1 upswept flat collecter racing style pipes fits a 79+ GS750, this is unfortunately just an error on their part, they mean a mid-1979 manufactured GS750 which would be a 1980 model.
Too bad because these are the best looking pipes I have come across for these bikes. The only pipes I like better are the early Yoshimura pipes, and some various Japanese brands of GS400/425/450 aftermarket 2-1's made by MadStar, MadMax, KSY Racing Project,

[Chuck78]

Hey everyone! greetings from portugal...

so as I was reading this thread it caught my atention due to the fact that I am considering buying a Delkevic exhaust to my 79' GS850. One thing, they site that no rejetting is necessary, but the fact is I am still running stock 4-2 headers and marving mufllers ( wich might I say top quality! ). So will it need to be rejetted?

The bike will still run without rejetting, if that is what you're asking.
Heck, even mostly stock old well used bikes will require rejetting to maximize the performance (some when brand new, even!), so your answer is likely a NO, you must check the jetting regardless!
The Delkevic pipe is a small diameter baffle (the upswept race pipe version is, the megaphone is a very large ID performance baffle), but even the small diameter baffle is still a straight through performance type baffle! The jetting requirements are different from stock, and are different from the large inside diameter megaphone baffle, which flows substantially more and has more of a bark to it.

So for you, the answer should be "DUDE!!!! Just learn how to re-jet your carbs! You will be happier in the end!"
We are all here for you and can instruct you on how to test jetting, how to remove carbs, how to clean the carbs (a very very wise choice, if you don;t know how to re-jet carbs, you probably have never cleaned and rebuilt your carbs).


So yes, the bike will run with the upswept road race pipe versus a stock pipe with stock jetting, but there is more performance to be had and more reliability and efficiency as well, if you just learn how to check your jetting by reading your spark plugs through doing plug chops at various throttle positions. Or have a vintage bike mechanic do this for you or assist you.
I don;t think you would want to run the Delkevic Megaphone or a Vance and Hines pipe without rejetting, however. Larger baffles. Substantially more flow.

[miguel]

The bike will still run without rejetting, if that is what you're asking.
Heck, even mostly stock old well used bikes will require rejetting to maximize the performance (some when brand new, even!), so your answer is likely a NO, you must check the jetting regardless!
The Delkevic pipe is a small diameter baffle (the upswept race pipe version is, the megaphone is a very large ID performance baffle), but even the small diameter baffle is still a straight through performance type baffle! The jetting requirements are different from stock, and are different from the large inside diameter megaphone baffle, which flows substantially more and has more of a bark to it.

So for you, the answer should be "DUDE!!!! Just learn how to re-jet your carbs! You will be happier in the end!"
We are all here for you and can instruct you on how to test jetting, how to remove carbs, how to clean the carbs (a very very wise choice, if you don;t know how to re-jet carbs, you probably have never cleaned and rebuilt your carbs).


So yes, the bike will run with the upswept road race pipe versus a stock pipe with stock jetting, but there is more performance to be had and more reliability and efficiency as well, if you just learn how to check your jetting by reading your spark plugs through doing plug chops at various throttle positions. Or have a vintage bike mechanic do this for you or assist you.
I don;t think you would want to run the Delkevic Megaphone or a Vance and Hines pipe without rejetting, however. Larger baffles. Substantially more flow.

Roger that!!

Thanks for the support! I think I will learn how to do it. Heck, I have to! thats one of the main goals for me.....working my GS by myself ( with you guys helping out if possible from time to time )

Best regards

[Chuck78]

Just be sure to start your own thread if it is very specific to your bike and in-depth beyond what we covered already here.

Also, I see you have a 79 gs850. That is a good thing, because I feel that the VM carbs are easier to work on or someone new to working on carburetors. 1980 started with the Mikuni bs32 constant velocity style carburetors. They are more user-friendly in terms of twisting a throttle without thinking about it, but they are little more to rebuild and not as performance-oriented.

[mavrik]

Anyone know what chuck's been smokin? This thread was started by me inquiring about exhaust fitment for my 1979 GS750... no talk of carbs here...

Anyway I did find the correct system for my bike... NCS had the black mac system on for $287.00 so I offered $250.00 and they accepted that offer... as per quality I don't expect to keep the bike after the rebuild is complete...

Thanks for all the info guys...









Chuck I did see the jetting post in here... just messing with the SAGE...

[cowboyup3371]

Mavrik, someone tried to piggy back off of your thread instead of starting their own; Chuck was just answering that person