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M.L. Toys
KidsWheels
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HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Need new motors? Grind a gearbox? Adding teeth to a pinion?
User avatar
By jjp735i
#146718
I have this Kawasaki quad, Model C7478-9993 and have read so much on motors and pinions my head spins. All I would like to do is get a better motor for more torque so that it will go in grass and up small hills.

I'm running 12v now, but have a 6v battery so I could easily upgrade. Not looking for speed, just more torque.

On a side note. I took her lil 6v quad and put traction and 12v and it pulls wheelies. Needless to say I had to take the traction off the rear wheels.

Thanks jjp
User avatar
By Hammer-fm
#146727
If this uses the same gearbox/motor combo as the J8472, it's a 17T motor with a 15-17T 7R gearbox.

If it fits (I don't know what the space around the motor looks like), the cheapest way to get more torque is to order two Nichibo 7013F "7" series motors ($16 for 4, shipped to your door), two 16T pinions (5mm hole, 32DP), and either fabricate two spacer/centering sleeves (1/2" PVC pipe and an 11/16" drill bit) or buy them from mltoys (775 to 7R mounting kit - $11).

On 12V this will give you about 40% more torque and it will be slightly slower (16T vs. 17T means 6% slower). Unlike other 775 motors (like the 8514/Banebots 18V), this won't stress your wiring & battery setup.

Motor link:
http://www.ebay.com/itm/Nichibo-Taiwan-775-7013F-R-12VDC-Motor-12-610-RPM-4-pcs-/112230651034?epid=503587959&hash=item1a2177d49a:g:i5gAAOSwImRYSaDp

Example pinion gear:
http://www.ebay.com/itm/HobbyStar-32DP-Pinion-Gear-16T-Hardened-Steel-5-0mm-Bore-5mm-32-Pitch-16-32P-/171955600929?epid=525168309&hash=item28095a3e21:g:-0cAAOSw8GhZhNDf

Mltoys mounting kit:
http://www.mltoys.com/product-p/775-to-7r-mounting-kit.htm


Note that these motors come without any flats on the drive shaft end and the pinion gears use a set screw, so you need to file/grind a flat into the shaft.

Or you can run what you have at 18V - -this will increase the torque of your current setup by roughly 50% as well as the speed -- but you'll probably burn through motors fairly quickly if you're doing a lot of hill work.

The 775 Nichibo motor I linked should take 18V without any issue.
User avatar
By jjp735i
#146728
That is just the information I was looking for. What is nice I can upgrade to 18v after she gets a bit more comfortable driving .

Thank you, jjp
User avatar
By jjp735i
#146748
Well it turns out it's not the motors that are week, it is the battery the guy told me was still good. It is junk, guess you can't trust everyone on Craigslist. I hooked up the new 12v sla I got from TSP and this quad really moves. I had to install the lock pin to keep my little girl save for now until she gets better.

Still for 15 bucks for the quad I'm happy. I knew not to pay the extra 20 for the battery, should have stuck with my gut feeling.

Thanks, jjp
User avatar
By jjp735i
#146753
Thanks, I already have both. For some reason I didn't even think of checking the battery since the guy told me it was holding a charge well. It does run on the stock battery, just on flat pavement.

jjp

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