How To : Homemade Cooling Fan Air Scoop

[90GTVert]

Homemade Cooling Fan Air Scoop

This was performed on a Minarelli two-stroke. Other engine styles may need slightly different steps or modification.

I have heard that this can drop temperatures a few degrees, but don't know how true it is. It seemed cheap enough to be worth a shot to me, and I even had my cooiling fan/engine cover off of the scoot already. My scoot is a 2004 Vento Triton 2 stroke (1E40QMB), other scoots will have a slightly different setup.



I measured the fan cover and determined that a 4" pipe would do the trick (the same size the GY6 folks usually use). I picked up a 90 degree 4" PVC elbow from the local hardware store for $4.99. This ended up being my total cost, because I had all other supplies around.










I didn't want the whole end piece on the PVC elbow. I measured how far my fan cover rises up around the opening in order to keep enough of the larger section of pipe to clear it. It rises up about 1/4", so I marked the PVC pipe to leave 3/8" of the larger section and placed it in a vice. I used a sawzall for the cut, but a chop saw, hacksaw, or other tools would work.










I only want a small scoop, so I marked the pipe (a few times lol) where I wanted it cut. I used a vice and sawzall again.










As you can see, there is enough of this pipe left to make another scoop.






Now I cleaned the pipe up and checked the fit and look on the cover. I also held it up to the scoot to check for clearance issues.






Now I used some 100 grit sandpaper and roughed up the surface of the cooling fan cover where the pipe will sit as well as the side of the pipe that will mate with that surface. Then I used Plastic Welder (sold at auto parts and hardware stores) to glue the PVC to the fan cover. I held it in place for a bit to be sure it set properly. It's not shown in the pics, but I went back and got some Plastic Welder around the inside seam.










Let the Plastic Welder cure before moving on to the next step.



My scoop is secured to the cover, but I can't leave it looking like it is. I decided to use body filler to blend the pipe into the cover. I used Rage Gold body filler with blue cream hardener.






I use a little more hardener than the directions call for to get a faster cure. It ends up around this color for a pretty quick cure. If you don't wanna work fast, use a little less hardener.






I wore latex gloves and spread the body filler on with my finger, but there are many other spreading tools that you could use. As you can see, I'm pretty sloppy with it, but it works.






Let the body filler dry and then sand it smooth, trying to feather the edges of the filler to the cover. I used 120 grit and 200 grit for this step. I also sanded off castings and what not from the PVC pipe.






I still have indentations and imperfections, so I use Evercoat's Glaze Coat with blue hardener to fill and fix them.






I mix the Glaze Coat with extra hardener as well for less drying time.










Once again, I wore latex gloves and used my finger to smear on the filler. I tried to be a little more neat this time, but didn't worry about it too much.






Let the Glaze Coat cure, and then sand it to a smooth finish. Be sure to blend in the edges the best you can. I used 120, 200, and 400 grit for this step. You'll also want to use the 400 grit briefly to prepare the whole piece for paint.






I originally painted the whole part with flat black paint, trying to make it look more like it came stock on the scooter. The paint is still drying in this pic.






I painted it with satin black later and it looked much better and much closer to stock.



It's not perfect, but I like it. You may notice that there is no cooling fan installed in the first pic. I did put the cooling fan on. At the time of the pics my cylinder and other parts were off and these were mock up pics.

[90GTVert]

Here's a little different approach on a GY6 150 using a 4" PVC elbow to make an air scoop.



I started by cutting it with a hacksaw so it could aim forward, but not be so long. Then cut a little off of the other end to make it stick out less.




Then I marked where the nubs stick out of the fan shroud and cut grooves with a carbide burr to accommodate them.




I had to taper the inside to match the fan shroud so the PVC would slide all the way onto the shroud.



I cut into the PVC over the nubs so I could make spots to screw the scoop to the shroud.





Then I quickly painted the scoop black and mounted it again, with a little Plastic Welder on each screw to as a sort of threadlocker.





Mine was a very quick job with little concern for appearance, but it could be cleaned up and smoothed out to look better.