Cooling

[speedy1125]

I read that a "90cc fan" will bolt up and fit on a 139qmb and cools better because of bigger fins. I have a 50mm kit here and a 47mm kit otw so it seems to me that some better cooling would help. where can i get this"90cc fan"?

[90GTVert]

I got mine off of a 90cc Triton engine, one of my 90cc engines came with a normal 50cc fan. 90cc ATV suppliers are usually a good source for 90 parts, but it looks like they come with the same fan as the 50s stock from what their pics show.

If they do bolt to each other, this could be good news for an easy to find fan upgrade for the minarelli since the stock GY6 50 fan is bigger.

[mattdel]

Theres a guy over on another forum that used what appeared to be a cooling fan from a computer power supply. With some minor filing to the plastic box cutout near the back of your feet, it will sit there and blow air right at your motor.

[marshinman]

WOW, a computer power supply fan...
I cant see that working long as the computer power supply fan is not designed for the outside elements or the heat that a engine puts out.
The bearing will likely freeze up due to heat.
There is a post that 90GTVet put up where he designed a cooling tube from a PVC drain pipe that I think would be your best bet. I cant find the post but I am sure he can point it out to you.
If you want to add a electric fan go to your local junk yard and find a small cooling fan from a front wheel drive car that is used on the radiator. These are designed for the heat and for the outside elements. You should be able to find one small enough that you can mount above the motor and under the seat storage compartment.

[90GTVert]

49ccscoot.proboards.com/index.cgi?board=gentech&action=display&thread=394

[jmkjr72]

actualuy i have seen a few lc jobs where they use computer fans to air over the rads

i havent herd of any issues with them doing that

but on an ac scoot you are closer to higher temps

[90GTVert]

For an AC scoot the only way I think you'd be effective at cooling the engine with an electric fan would be to build a new shroud out of fiberglass or something and use a fan powerful enough to move as much air as the stock fan does at high revs. If your battery could take it, you'd drop some weight and load off of your crankshaft. That's a pretty ambitious project though. Also, the stock fan won't fail unless the engine stops turning or you manage to sheer off the blades or clog up the shroud or something like that.

Blowing air at the air shroud just won't do much I don't think. Maybe if you blow an awful lot at it, but a PC fan isn't gonna move that much.

[marshinman]

You are correct on all points there and one that I failed to recognize.
By using a large fan like one used in a car to cool the radiator will pull alot of current/voltage from the battery. I dont think the charging circuit is designed or will keep up with that kind of drain. Most likely it would eventually burn up the stator assembly or voltage regulator with that kind of a drain.

[Fox]

You are correct. The charging systems on these Chinese scooters barely have enough to power the scooter and keep the battery charged. I'd bet that most stators go out when people kick start the engine and drive with a faulty/weak/dead battery and/or add things like extra lights, stereos and amplifiers etc... They just aren't designed for all that stuff.

[90GTVert]

That sounds like my Venus. I ditched the e-start stuff long ago. Used to run with no battery. Now I put the battery back, but I have simultaneously powered a stereo and GPS or GoPro of course with the scoot's lighting as well. So far so good. I think I'm only drawing something like 1.5-2A with the stereo pretty loud and one accessory in the 12V outlet. That scoot's only using a 35W headlight and LED tail though. Many miles on the electrical components. Another scoot uses kick start with no battery and runs a 60W light. I'm stress testing for you.