Question on Stock Exhaust Mods

[krakum1967]

Not sure if I want to go down this road, but what type of modifications can be done to the stock exhaust to give the ol girl some grrr? I am also just slightly rich on the mixture and wanted to free up rather than rejet.

Its a 79 GL1000. Exhaust is stock and pristine, now you see why I may not want to mod it.

 

[joedrum]

with 78-79 weak cams it needs all the flow it can get .. seperate the stock system ..hang the back 1/2 on the wall and put on something that will flow better and you will get a bump in power ...

 

[zman]

Seen all types of mufflers, Someone claimed a Buell or maybe it was Ducatti was a bolt on affair, they were raised canister type, many just use take off Harley pipes but not sure of their flow characteristics, seen triumph muffs looked like Dunstall`s said sounded real deep/nice, nothing wrong with saving your old mufflers and using another.
By the way..It was Ducatti.
https://webcache.googleusercontent.com/s ... =firefox-a

 

[dan filipi]

Well my first thought is do we know if freeing up some flow will lean up the rich condition?
And speaking of rich, what is making it rich? Might be better to go after that than trying to mod something on with an unknown outcome.
What is happening that's making you say it's rich?
Low mpg? Gassy exhaust smell?
I would go after the cause personally but that's just me.

 

[krakum1967]

Yes, freeing up the exhaust (and air filter as well) leans out your mixture. That's why you need to rejet with most aftermarket exhausts.

I read the plugs, they tell me its slightly rich, and since I would like a little richer sound I prefer to match the exhaust to the condition as I am only slightly off.

Now that I actually have an air filter I really need to road test before I consider any major changes. I *have to adjust the air idle mixture again as on the Solex type carbs it is part of the overall fuel flow, so I should really tune it again with the new filter in place. My tinnitus typically prefers a quieter bike anyway.

But as others posted, the rear half of the exhaust will likely wind up on the shelf with the carbs as I have two cigar style cans sold in J&P's Vintage catalog on the way. I have used these before as they are baffled and give a nice rich sound, but they are legal and not overly obnoxious. They are sold for the old Panheads, but they are free flowing, pretty, fairly cheap (45 each), and are basically universal with some slight mods. I use one on the Hyosung/UM that my wife rides,and I like the sound.

Was really just wondering if there was a removable baffle or something like that. I will put the old mufflers in the back to stock pile with my growing accumulation when its time to get to it, I have some Patriot Guard rides coming up, so I am just going to tune to the current conditions for now. The ND PG Annual Meet and Ride is coming up in two weeks so I better just keep the ol girl running for now. Make changes later. I do enough work on other bikes that I get a little sick of working on mine. I think I will tune and ride for a few weeeks than I should have a better grip on my baselines and can get some jets lined up. Those have to be ordeed online so it can wait.

 

[krakum1967]

Oh the basically are the Dunstall type

 

[slabghost]

Sounds good. You could possibly make it slightly leaner still with a K&N air filter. But with the shiny new cans coming you may want to add a filter sock or bigger jetting.

 

[krakum1967]

I will reply on a new thread, its defintely rich under load, more over there. For now I have some tuning to do. I need to get a good baseline set with this conversion, and then handle the appropriate changes once the single carb is more dialed in.