82 GSX400, GS400 Exhaust

[Guest]

Hey guys.
So going through the list of things i need to do to get my GS resurected I hoped the the baffle out of one fo mufflers is completly rotted out. I am looking to put some universal style slip ons onto the the end of the headers

http://www.siriusconinc.com/pro-detail.php?pid=&product_id=271

My plan is to keep the header length the same so i dont have to play with the jetting. Since the GS400 has a one peice muffler I will have to cut the muffler of to find out were the header pipe ends and they extend it and then attach the slip on.

Im not sure if any other model GS would have the same exhaust that i could put a NOS or used system on.

I am posting this for product suggestions or advice

Thanks

[GS(X)400]

On retrospect and additional reading I dont think i am going to be able to avoid at least an increase of 1 jet size if i do the slip on route.

I would prefer to keep as stock so maby i will check around for some stock pipes localy.

Does anyone know if the exhaust from any other GS (450 specficly) will fit. They look the same but have different part numbers.

[GS(X)400]

I have decided that since im going to rejet I might as well just go ahead and get the 2-1. I have opted for the Motad exhaust from the UK and and gettign quotes.

The question I have is the MAC 2-1 will fit the US 82 450 Model. I think that this would also fix the canadian GS400 and it may be cheaper to go MAC as i have a local dealer.

Also I know i will probably have to look at going up 2 jet sizes when i do this but will i also have to increase the Pilot jet size or just turn it out a little more?

[koolaid_kid]

Not sure on the fit of the pipe, but you will not need to change your pilot jets, merely adjust the pilot air/fuel (mixture) screws a bit. And yes, probably turn them out 1/4 to 1/2 to start.

[GS(X)400]

Thanks Koolaid. I think i am going to go for the Motad unit they have a supplier is Chicago i know it fits. Their unit also fits the 450 so im guessing the MAC would work as well. I guess i would have to find a 450 unit and get some measurements.

[pete]

Can't help with your questions (don't know the exhausts) but if you get the Motad I'd be curious how it goes.

Years ago I got a quote for one installed and if I didn't go my custom route that I ended up doing that was my next option. They have a good reputation for quality apparently.

[GS(X)400]

I called MOTAD and its not made anymore damit.

The MAC exhaust seems like my only option. I guess i will have to take some measurements before I buy the thing.

[SVSooke]

I had a friend weld thes stubs on a set of stock 1000 header pipes.

So I could mount a set of long Dunstall mufflers I got in a bike deal.


Look pretty good.Bike's not running yet.

[GS(X)400]

Bike is looking good. I think thats going to have to be my solution.

From thsi thread

http://www.thegsresources.com/_forum...ht=MAC+exhaust

I see that the MAC 2-1 will fit. But seems the buyer wasnt happy with the performance and tunability. He said that he solved the issue but but never said how in the thread.. and thats not helpfull at all. So i can either drop 300 on a MAC that will fit but just might not run right. or go the route SVSooke suggested and go with more traditional slip ons that i know i can tune (Plus dual exhaust is was cooler than single am i rite?)

This just means i have a little more clean up on my stock ones that apparently have been painted with some kind of black power that falls of when you look at it

[pete]

Bike is looking good. I think thats going to have to be my solution.

From thsi thread

http://www.thegsresources.com/_forum...ht=MAC+exhaust

I see that the MAC 2-1 will fit. But seems the buyer wasnt happy with the performance and tunability. He said that he solved the issue but but never said how in the thread.. and thats not helpfull at all. So i can either drop 300 on a MAC that will fit but just might not run right. or go the route SVSooke suggested and go with more traditional slip ons that i know i can tune (Plus dual exhaust is was cooler than single am i rite?)

This just means i have a little more clean up on my stock ones that apparently have been painted with some kind of black power that falls of when you look at it

Have a re-read of that thread and you'll see how he solved it

The thread's actually about putting a Supertrapp muffler onto the MAC header, and fiddling with the number of discs in the Supertrap is what solved it for him.

Also, if you look at his comments about jetting, it shows the classic signs of not raising the needle and it looks like he only adjusted the mains. He says midrange was bad, and providing he had the throttle between 1/8 and 3/4 open, that would say he didn't touch the needle to tune it.

Sounds to me like the MAC might be ok with the right jetting...

[GS(X)400]

Thats was i suspected but im still learning about carbs and didnt want to drop 300 on somthing i have no clue how to tune. I have found a performance shop near me that has experince with these bikes and a dyno i might get it there way to get setup and carbs cleaned.

What would you expect the needle to raise to? 1 spot?

[koolaid_kid]

First, you do nothing with the needle until you tune the main jet. Basic CV tuning. I'll have to find that tuning page and put a link in my signature.
Second, and this is my opinion only, in your shoes I would take a step back and rethink.
Your muffler(s) are rotted out but the header pipes are decent, correct?
I would get a pair of Harley take-offs and use them. Get some that are about the correct length and the style is not objectionable to you. If the diameter is too large, have a shop make an adapter to your header pipes. Fit it up, make mounting brackets, have it welded up, and that part is done.
Harley owners tend to take their mufflers off immediately and so you can find some in excellent shape for not a lot of cash.
Then start tuning your carbs.
O.K., end of lecture.
Best of luck.

[GS(X)400]

I am weighing my options and will take you advice into consideration.

Any ideas on a source for harley take offs?

[koolaid_kid]

eBay has lots of them.

[GS(X)400]

Yea i saw lol... Is there anyone you would recomend or suggest i stay away from?