1981 GS1000G exaust fitment question

[von reckless]

I have a 1981 GS1000G that needs new pipes. As I research options, I'm getting conflicting information. Hoping the forum can help me out.

According to Ebay (not a source I like to trust as far as fitment is concerned), Vance and Hines makes a 4-1 "megaphone" system specific for this bike (year, make and model). Can someone confirm this from first hand knowledge or experience?

I understand 4-1 systems are the best for performance. However, I am running a faring and saddle bags, so the look of my bike is of a tourer, not a performance bike. And I'd rather not have a super loud bike. I'm also concerned a 4-1 system would conflict with my saddle bag on that side.

That said, Mac makes a 4-2 "turn out" (this would be perfect for my needs) and a 4-1 "megaphone" system. On their website, they say both these systems fit 1980 GS1000G bikes. However, they do not state explicitly that the pipes will fit 1981 GS1000G bikes. I thought there was no difference between these two years. Could someone confirm this for me?

Finally, does anyone know from first hand knowledge or experience of other full exhaust systems or slip-on mufflers that are specifically made to fit this bike (or slip-ons that happen to fit with little modification to the stays)? I'd like to keep the cost to under $500 and I don't need headers.

Thanks!

 

[Guest]

There is no difference between an 80' and an 81', with anything, including the exhaust. MAC never seems to have a good reputation, thin metal, discolours quickly and sometime the carbs have to re-tuned for the pipe but I have no direct experience with any MAC pipes, only what I have read. One thing I did with my 79' 850G was buy a set of Dunstall mufflers. They were louder than stock but their baffles were removable so packing them with proper baffle wrap helped to reduce the noise a lot. They're only about $70 a piece. You can get ones that look 'almost' stock. I had a fella welder them to the header but others have had a pipe welded into the header that the muffler would slip over and tighten down onto.

 

[SVSooke]

There is no difference between an 80' and an 81', with anything, including the exhaust. MAC never seems to have a good reputation, thin metal, discolours quickly and sometime the carbs have to re-tuned for the pipe but I have no direct experience with any MAC pipes, only what I have read. One thing I did with my 79' 850G was buy a set of Dunstall mufflers. They were louder than stock but their baffles were removable so packing them with proper baffle wrap helped to reduce the noise a lot. They're only about $70 a piece. You can get ones that look 'almost' stock. I had a fella welder them to the header but others have had a pipe welded into the header that the muffler would slip over and tighten down onto.

One of "the other guys" azr mentioned was me.

Starting with a set of good head pipes with rotted out mufflers he gave me.


Had a friend at work weld on some stubs to clamp a set of long Dunstalls on to them.



Look pretty close to stock on my 78 1000.

 

[von reckless]

I really appreciate your help (pictures are great). I also like that you are recommending an affordable solution . . . although I don't have any welder friends, so that will add to the cost if I go for aftermarket slip on mufflers. Any body out there know of slip ons that yield a nice exhaust note without being too loud (requiring me to fuss with baffle wrap)? I know, I'm just being lazy.

Haven't yet ruled out the Mac system. So I'm wondering if azr's low opinion of Mac pipes is a generally held consensus. Any Mac owners out there to comment?

 

[duaneage]

MAC pipes are of low quality. The baffles in the end are poorly made and far from engineered for your engine.
I run a V and H street pipe, about 375.00, and it's a decent item. It's not as good as the Marshall on my 650 but Jama/Marshall discontinued their 1000 pipes so I went with V and H instead.

Chrome is holding up OK. Sound not too loud. A slight bump in the main is all I needed to make it run right. I might try shimming the needles for better midrange but it's on a stock engine with an airbox.

For a few nickles more, get anything else but a MAC.

 

[von reckless]

I run a V and H street pipe, about 375.00, and it's a decent item.

That is the 4-1 system, I assume?

 

[von reckless]

MAC pipes are of low quality. The baffles in the end are poorly made and far from engineered for your engine.

MAC never seems to have a good reputation, thin metal, discolours quickly and sometime the carbs have to re-tuned for the pipe

That's two votes against the Mac. I'm leaning away from them, but I do have one more question for you guys . . .

There is no difference between an 80' and an 81', with anything, including the exhaust.

When I asked sales at Mac to explain why the system for the 1980 GS1000G would not fit the 1981 GS1000G (thinking there might be a very minor alteration I could make), here is what he said: "The Tube size is different and the routing of the exhaust system. Suzuki's changed there models in 1981. They differ from the 1980 models. The main difference is that the 1980 models are a 2Valve and the the 1981 models are a 4Valve. This made the Head Pipes a different size." So . . . do the guys at Mac have their heads up their arses or are they right about these differences?

 

[Guest]

They 'sort of have their heads up their arses'. The G models did not change in those years. They are both 8 valve engines. The bikes are identical in every sense of the word. The only thing that changed, and I'm not even sure if it did, was the paint schemes. I'm sure someone can chime in on the paint colours. Suzuki did start to change over to 16 valve engines in the early 80's but not for the 1000G. It's last year of production was 1981 and it was an 8 valve motor. Now if you buy an 1100 it is a 16 valve but you can still make the exhaust fit, the only thing that doesn't line up perfectly is the rear mounting brackets I think, there's actually a few different bikes that you could make the exhaust work from, but if you want straight bolt on an 80 or 81 1000G are identical.

 

[850 Combat]

The difference between the 1980 and the 1981 is the turn signals. They went to running lights in front with a dual filament bulb in 1981. The wiring harness is slightly different to accommodate the running lights. Also, the turn signals are flat black plastic with rectangular lenses, rather than round lenses and chrome. I own both years. My 1981 has a 1980 850G wiring harness I got off this list, which is right, except I put a jumper off the headlight to run the running light circuit. The pipes should fit.

1981:



1980:


(With 1983 1100G motor)

 

[Guest]

Good God Paul I wouldn't want you sneaking up behind me with THAT horn!!

 

[850 Combat]

Both of those bikes have LOUD horns. Courtesy of the POs. The dual air horns on the black one are somewhere between diesel truck and freight train. Ugly, but I'm keeping them. The ones on the red bike are way bigger than stock, but can pass for OEM. They are like super loud car horns.

If its any consolation, on my other G, the one I rode to Charlie's, the horn doesn't work.

Remember the deer eating under the fig tree in the front yard when we were working in the driveway?

 

[Steve]

When I asked sales at Mac to explain why the system for the 1980 GS1000G would not fit the 1981 GS1000G (thinking there might be a very minor alteration I could make), here is what he said: "The Tube size is different and the routing of the exhaust system. Suzuki's changed there models in 1981. They differ from the 1980 models. The main difference is that the 1980 models are a 2Valve and the the 1981 models are a 4Valve. This made the Head Pipes a different size." So . . . do the guys at Mac have their heads up their arses or are they right about these differences?

They are definitely NOT right.

Suzuki did start to change over to 16 valve engines in the early 80's but not for the 1000G. It's last year of production was 1981 and it was an 8 valve motor. Now if you buy an 1100 it is a 16 valve ..., but if you want straight bolt on an 80 or 81 1000G are identical.

Yes, the 1100 went to 16 valves in 1980, but that was the chain-driven model, not the shafties.
The shafties did not get 16 valves until 1991, when the GSX1100G came out.

Now, back to the years being discussed. The '80 and '81 850G and 1000G (and their GL versions) were virtually identical, they even shared the same part number for the frame. In a similar manner, the '82 and '83 850G and 1100G also share a frame part number, but it's different from the earlier years. Also be aware that the 1100G was still an 8-valve engine, while the 1100E was a chain-driven 16-valve.

I have had (or still do) an '80 and '81 850G, there were NO differences in the way the exhaust was routed. Based on that, I would say that there are also no differences between the '80 and '81 1000G.

Where MAC is messing up is that they are thinking of the '80 1000E (and S), which were, indeed 8-valve engines, and the last of their kind. The only 1000 that happened after that was the Katana, which was a 16-valve engine.

By the way, the '80 1000E and '80 1000G don't take the same pipes, so make sure you get pipes for the better shaft-driven bike.

.

 

[850 Combat]

They are definitely NOT right.



By the way, the '80 1000E and '80 1000G don't take the same pipes, so make sure you get pipes for the better shaft-driven bike.

.

People on this list have interchanged them, reportedly without much trouble.