Suzuki DR650 Air Filter Page
There aren't a whole lot of options for DR650 Air filters.
The stock air filter seems more than adequate. It can be recleaned in solvent, gasoline, or water and detergent and then reoiled with motor oil after the filter dries completely. You can use a hair drier to help speed the drying process if you are really impatient - just be sure to avoid melting the foam filter or blowing yourself up if you used solvent or gas.
Stock Pre 96 DR650 Air Box
Reference Part Numbers:
1378012D00 Pre 1996 DR650s
1378032E00 Post 1996 DR650s
Oiled Cotton Gauze Air Filters - K&N
K&N Filter for Pre 96 DR650
K&N has a popular reusable oiled air filter system that is used in many high performance vehicles. The company claims their filter will filter out smaller particles than the standard paper filters used in autos, while allowing more air to flow to the engine. This would increase the life your engine, give it a few extra horses of power and eventually pay for itself in fuel savings. You'd have to be an idiot not to use one in a car! Well, maybe. There are some independent tests (or those done/funded by other filter companies) that demonstrate poorer filtration.
Aftermarket Oiled Foam Filters
Like the stock air filter, other oiled foam filters allow for good filtration, decent air flow and a higher capacity for dirt collection than comparable sized paper air filters. They can also be easily cleaned and reoiled as long as you don't mind getting a little oil on your fingers.
Twin Air produces a dual stage foam filter that claims the following:
Coarse open-pore outer foam catches airborne dirt, grime and sand.
Fine open-pore inner foam acts as a second filter to trap the smallest particles while ensuring maximum air passage.
Exclusively formulated adhesive ensures glue seams will not break down.
Thick, flat foam, greaseless sealing ring ensures maximum contact with your airbox, while acting as a breathable gasket for increased air passage.
Fused outer and inner elements prevent dirt and grime from being lodged between layers, unlike Twin Air, this can be a problem with inferior two piece designs. Trapped particles can restrict airflow. And if dirt works its way into your engine, a pinhead sized granule will gouge your cylinder, piston and rings like a bullet.
Designed to be smaller than stock filters to increase the airspace around the filter.
Secondary Air Filter
Post 1996 DR650s have a secondary air filter under the seat. These can be replaces with an upgraded aftermarket filter.
Unifilter - 96+ air filters NU-4130FO - also mini secondary filter
Topgunmotorcycles secondary air filter UNI Filter
Paper filters are generally not used on offroad bikes, as they are more difficult to service (requiring replacement and not simple field cleaning and reoiling) and don't do well if they get wet. When they get wet, they prevent the flow of air through them which will cause a your engine to run rich or not at all. After they dry out, they should allow for air to pass, but it will be more difficult for air to pass through the dried out matted areas of the filter that were previously wet. The cost of paper filters will also eventually add up, which makes it coast prohibitive for most riders.
Oil-Free Synthetic Media Air Filters
These are made with multiple layers of synthetic cloth that filter out particles without the use of oil. This allows for cleaning by tapping the filter, vacuuming or even just washing with soap and water.
Stainless Steel Air Filter
Steel shiny and cleanable. If you want to use one on a DR650, you'll have to get creative.
Oil Bath Air Filter
This was widely used until the early 1960s when paper air filters gained popularity in the automotive world. This system uses some sort of mesh, and oil bath and a labyrinthine path for air to travel through. Dirt is trapped and collects in the oil. This allows for a very high capacity of dirt collection, but makes for very messy maintenance and doesn't filter as well as other air filters available for automobiles and bikes.
Oiling Foam Filters
Where there's oil, there is debate. Suzuki and others recommend just using regular motor oil for the stock air filters, but riders have used synthetics, special "sticky" filter oils, spray on filter oils, K+N filter oil, chain oil and even vegetable oils.
According to Uniflow synthetic oils should not be used:
The best oil for foam air filters is a mineral-based oil. Unlike synthetic oil, mineral-based oil will never dry out. A synthetic oil may be good for inside an engine, but when used on a filter in dusty conditions the oil will dry when it comes into contact with dust. Once the dust comes into contact with a synthetic-based foam filter oil, a dry crust will form on the surface of the filter allowing more dust to pass through the filter and into the engine. Unlike a synthetic-based oil however, a mineral-based oil will soak through the dust and continue to catch new dust thus protecting the engine.
They also feel that K&N filter oil is not compatible with their filters and that propellants in spray-on oil treatments will shorten the life of the foam.
Air Box Mods
There are a couple of air box mods used by DR650 riders. One is just to remove the air box door. This allows a lot more air in the box, makes a lot of noise and decreases the protection against water and dust your filter has. Others remove the snorkel and/or cut out holes in the top and/or sides of the box.
The rubber snorkel does seem a bit restrictive and unless you are going to ford waist high water on occasion, you are probably ok removing it. If you later decide you are better off with it, you can squeeze it back in its hole. Some feel that removal of the snorkel will necessitate a needle raise of 1-2mm.
Note that modification of the standard airbox, such as removing the cover, drilling holes into the side or top will have a drastic effect on smooth carburetion. Modifications will cause a stock system to run lean and reduce horsepower. You may need to rejet and adjust things to make it all work. See our Carburetor page for more information.
Suzuki recommends that you clean your air filter every 3,000 km or 2,000 miles. The following is from the Pre 96 DR650 maintenance manual.
If the air cleaner is clogged with dust, intake resistance will be increased with a resultant decrease in power output and an increase in fuel consumption.
Check and clean the element in the following manner.
Remove the left frame cover.
Remove the air cleaner case cover by removing screws.
Remove the air cleaner element by removing bolt.
Remove the polyurethane foam element from the element frame.
Fill a washing pan of a proper size with non-flammable cleaning solvent. Immerse the element in the cleaning solvent and wash it clean.
Squeeze the cleaning solvent out of the washed element by pressing it between the palms of both hands.
Immerse the element in motor oil, and squeeze the oil of of the element leaving it slightly wet with oil.
Do not twist or wring the element because it will tear or the individual cells of the element will be damaged.
Inspect he element carefully for rips, torn seams, etc. If any damage is noted, replace the element.
Reinstall the cleaned or new cleaner element in the reverse order or removal.
If driving under dusty conditions, clean the air cleaner element more frequently. the surest way to accelerate engine wear is to use the engine without the element or to use a ruptured element. make sure that the air cleaner is in good condition at all times. Life of the engine depends largely on this component!
Not in the repair manual - a less messy way of oiling your filter is to put the filter and oil in a zip-lock bag, manipulate it to get it oiled, cut a hole in the corner of the bag, and squeeze out the extra oil back in the container.
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