Burgman 400
 

So, I'm as new to this as one can get. I've changed my oil over to fully synthetic in both the engine and final drive. I installed 19gram Dr. Pulley sliders in the cvt along with a new belt. Can't seem to find an aftermarket clutch so any suggestions? I am at 75 mpg usually. I mostly highway ride. I just put on a custom exhaust that has it way less restricted. And by doing that, it tends to smell like gasoline. I think it's dumping more gas than it need to since there's no O2 sensor for my model. Yes it's FI. I'm looking at what I can do to make it more aerodynamic to cut resistance too. Any recommendations are much appreciated.

There are some great threads here on motorcycle aerodynamics. Start by looking at craigvetter.com for the latest developments in full body fairings. Decide if you are inclined to lean forward or backwards to lower your profile. The nose piece needs to be fairly stiff to resist the wind pressure and the bulkhead just behind the rider can be plywood or honeycomb aluminum. I like using sailplane fuselage plans to get a good shape. See www.vintagesailplaner.com/Sheet1bis-9.pdf or look for free sailplane plans.
The dealer's mechanics may be familiar with adjusting FI to aftermarket exhausts or they may know some tuners that race prep engines. Check with MotoQ.com on their Powersport projects for scooters too.

Ok. So looks like what I want to do is streamline the front wheel. Any idea how to do this and still be able to turn the wheel? Also where it won't look too bad?

People's tastes vary. Compare these two profiles:

http://i142.photobucket.com/albums/r...d/100_2771.jpg

http://jinx.smugmug.com/Motorcycles/..._McsoM-L-1.jpg

Which do you prefer?

Regarding ability to turn the wheel: There are three issues

1. Will your steering move unobstructed inside your fairing?
2. Will your wheel fairing interfere strike, rub, or damage your body fairing?
3. Will your wheel fairing so strongly affect air flow that balance is upset?

The first two can only be solved by measurement and trial-and-error. Consider using cardboard, zip ties, and duct tape to avoid remaking expensive parts. Once you have a good shape, transfer dimensions to your final materials.

Issue three is problematic. The size and shape, and the interaction between fairings causes great variation in balance upset. Only actual testing will tell you if your solution is viable. It seems to be true that many avoid separate fairings, opting for only a body fairing, to avoid balance upset complications. However, note that the two images above both include two fairings. The very high speeds of the two machines, and the predominant need for straight-line operation (less steering), may explain the design choices.

I'm really not sure what I could do to make it more aerodynamic and cut the wind better. I have a taller windshield on it already. I'm gonna try and call around about the FI adjustment.

The three issues have been addressed in several threads. The best practice for road bikes is to form a shell and cut a "smiley face" opening for the tire to move lock to lock. Vetter details this very well in chapter 54. A faired wheel needs to have its center of pressure behind the steering axis for stability. Much of the design work can be done using a half scale cardboard model.

Many of the contributors began by lowering their body position and changing the front fairing/windscreen. Next step was filling in the space behind the rider.

Ok. So I want no open space behind me?

looking at those two salt flat bikes and their half fairing wheels got to thinking why no one has thought of this:

http://ecomodder.com/forum/member-xu...eelfairing.jpg

or maybe they have, I envision the forward half mating in an aircraft door sort of way or simply overlapping the rear half. it's a simple crude drawing but you get the idea.

Wheel cover discs and wheel fairings can work on the front only if the center of pressure is BEHIND the steering axis to prevent wind induced steering.

Once you decide on the position of your shoulders, the rear fairing tapers down at about a 4 degree angle. The bottom angle is usually up 8-10 degrees. With a scooter your wheelbase is longer than a motorcycle (62" vs 56") and your CG is lower and further back. Make the tail as long as you feel is practical for your situation. At 30" wide, a 5:1 ratio puts your total length at 150" or 12' 6".

If you really want to get the engine running right with the new exhaust you will need a piggyback fuel controller.
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Bazzaz for Suzuki Burgman
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And a dyno session to tune the mixture at the tail pipe. Or the additional wide band O2 sensor mixture mapper.
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Accessories : Z-AFM Accessories
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Maximum fuel economy looks like you will want to set the weights to cruise at (or below) 5,000 rpm. Maximum acceleration and horsepower peak is from 7,000 to red line but I can't really see needing to tune the pulling rpm's that high with 40 hp on tap.

He's doing very good at 75mpg if that is really what he is getting. My '06 Burgman 400 gets right about 64mpg at 60-65mph (65-70 indicated). This is over at least 15 tanks of fuel on my 48 mile each way commute.

I have 21g Dr. Pulley sliders, an old belt, a tall Clearview windshield, de-restricted airbox with WAI, loose valves, .035" plug gap with back cut ground strap, tires inflated to sidewall max.

Exhaust is stock, but peering inside the exhaust it glows dark orange after riding. It's a common occurence on these bikes and possibly indicates a new exhaust is in my near future.

Any advice on a low restriction and quiet exhaust?

Not sure if the 400 Burgman is anything like the Honda Reflex exhaust wise. The exhaust restriction on the Reflex has to do with getting the temperature up and working the catalytic component in the muffler. These engines are air pumps of sorts. Move more air through, and more fuel is required. Some engines like the 249cc engine of the Reflex seem to be designed/tuned for certain amounts of power at relatively low fuel flow rates. Tweaking for more HP by de-restricting things generally means more fuel will get used. Sure, the Reflex uses a carburetor, but I believe this to be true even with FI engines. Some have tried using less restrictive exhaust systems, but also needed to do jetting changes as well so that they would run..."properly". (and that = more fuel use)