exhaust drilling

[cptomlinson]

i have a 1980 XS1100SG and I am considering drilling holes in the baffles to get a louder, deeper tone. does any one know how many and what size holes i should drill and what carb adjustments, if any, may be necessary. I have the factory air-box on the bike. The Exhaust is not stock. I think they are called cross-overs. Any advice would be appreciated.

[tinman905]

When you say "cross overs" do you mean they cross over in front of the engine or underneath behind the center stand?

[cptomlinson]

they cross-over in front. the 2nd pipe goes to the right side with the fourth and the third pipe goes to the left with the first.

[Bigfoot]

Some members will probably disagree with me but I would not do it. I have seen many times that an exhaust leak will seriously drop the bikes power. I am pretty sure it has to do with the backpressure. If you start drilling holes to change the sound, you will decrease the backpressure and will lose power IMHO.

[cptomlinson]

speaking of crossover, i would love to know what purpose this serves and maybe an idea of the manufacturer. i bought this bike 6 years ago and it already had this exhaust. the headers and mufflers are in excellent condition but not loud enough.

[cptomlinson]

thanks bigfoot. that is a concern of mine as well but i did not know to what extent this was true.

[Bigfoot]

I think you have what are known as the spaghetti pipes, probably Jardine brand. What is commonly known as the crossover is the pipe that connects the two mufflers back by the centerstand.

[cptomlinson]

are these spaghetti pipes intended to produce more HP/Torque? what gives?

[tinman905]

That exhaust is high in demand and would be a shame if you drilled holes in them. There was one member a few days ago that was just saying he regretted drilling his Jardine Spaghetti exhaust .

The purpose of the cross over is to synchronize or help balance the exhaust pulses from each of cylinders .This will increases exhaust velocity and scavenging from each cylinder which will result in more low end torque and a bit more horse power at the top end plus get you better gas mileage.

[cptomlinson]

you are right tinman but i am not positive that they are Jardine spaghetti pipes.

[cheezy]

for what it's worth. leave the factory exhaust alone! yamaha spent a tlot of money developing this exhaust. i have messed with exh systems on 5 different bikes. there are gains and losses with every mod. i had an 83 750 midnight maxim. that bike ran the best, had the best power band with the stock collector and mufflers. i had welded and patched that collector many times over the yrs to keep it going. there was a guy on the xj site that was actually building them a few yrs ago. i gutted pipes on my vstar 1100, and my vts1300. i went back to stock because they didn't run as smooth or consistant. stock maybe quieter, but the overall performance was better. i used harley mufflers on my 77 goldwing because stock mufflers were just about impossible to find. i the bike never ran as well as the stockers, so i welded and patched up the originals, and many mysterious power issues went away. i know i'm new to this site, but i've been tinkering with bikes for a lot of yrs. so for what it's worth, if you don't like the stock exhaust, sell it to someone before you destroy it, as i don't think they're making any new ones. maybe you can ask around and see if anyone has a modified set they'd sell or trade you?

[cptomlinson]

thanks for the advice cheesy. i actually have two of these elevens, one for parts that has the stock exhaust in good condition. so i figured if i did hose one system, i would have a backup. the bike sounds ok but like i stated earlier, i need more sound.

[CatatonicBug]

you are right tinman but i am not positive that they are Jardine spaghetti pipes.

Well, take a picture and show us, and we can tell you!

[Ivan]

i have the Jardine spaghetti exhaust with megaphone mufflers. It actually looks more "stock" than stock the way it mounts on the bike. As far as performance, they are great, and have a nice smooth and quiet sound. That's important for a 500 mile run in the saddle.

If you are looking for top end power, the Jardines could be opened up a bit. They are a tad restrictive on the high end. I would start with one hole in each side, probably 1/4 inch and then ride it for a few days to get a total feel for the difference. You'll start loosing torque with the openings, so pay attention to that.

Look at the Kerker Muffler thread. I am going to take some measurements and email Hugger for a suitable SuperTrapp replacement core part number and I will report it back when I get it. That would make the Jardine tunable and probably the perfect exhaust. Open it up around town and let it growl or tone it down for long road trips. It will be pricey, but more than likely worth the money, in my estimation.

[Crazcnuk]

I have a good set of MAC 4 into 2s I would gladly trade for a Jardine Spaghetti system!

It won't have the same performance, but it has a much deeper tone so you won't feel as bad with your Harley buddies!

Start drilling holes in a good stock, or Jardine and you may get pummeled! (figuratively :^))