daztrac

I run a GT7 in my B4 with a CO27 stock motor.
I have noticed just recently that it seems to be down on power quite considerably, and after a race the motor is red hot.
I haven't cooked a motor yet, but they get extremely hot, more than usual.
I tried a brand new motor, which had reasonable power for the first 2 laps, then it faded, I assume due to being too hot.
I checked with another guy I race with, who was running the same motor, same speed control, and the same gearing, and his motor wasn't anywhere near as hot. Also he was lapping me, which usually doesn't happen.
I have tried lower gearing than I normally run, but the motor still gets very hot and is down on power.
I also tried resetting the speed control, but it made no difference.
I have checked the transmission for seized bearings, but it is all smooth.
I haven't changed anything to what I normally run, except for gearing to try and save the motor.
I am wondering if it could possibly be the capacitor is faulty?, or some thing else?
Has anybody else had this problem?

TheTurtleMan

iTrader: (31)

Its probably the motor. Try a different one and see what happens.

If not see if you can try a different ESC and see what happens. I wouldn't think it would be the cap, but you never know.

M Chambers

Sounds like the issue is your motor. In general, stock motors run HOT... but they will run even hotter if your gearing is off, if the track surface has a lot of traction, or if you are running for more than 5 minutes at a time. From what I understand, the CO27 is a rpm based motor which will require you to gear it a few teeth lower than say a P2k2 which is more torque based. Check your motor thoroughly and assure that the bushings get a drop of lubricant.

Also, if you can find someone who has a motor runner (for example: LRP charger) put it on there and set the voltage at 5 volts. If the motor pulls between 5 and 9 amps it is running normally. If however it pulls over 10 amps it will be incredibly inefficient and can cause the motor to heat up excessively.

As for the speedo, It couldn't hurt to invest in a new capacitor to see if that is effecting anything. Novak sells them for a reasonable price. If for some reason the speed control is the problem, contact Novak and they will be sure to repair it for you.

daztrac

Thanks for your suggestions guys, but I have tried three different motors, one of them brand new, and I always lube the bushes before every race.
I checked the motors on my charger, and they are pulling 5-6 amps@ 5v.
I have tried, but can't seem to get through to Novak, the emails keep failing.

nutz4rcyktw

iTrader: (67)

Call them and discuss. I have never had a problem with them helping over the phone. If you need to send the GT 7 in, download the form from their Website and ship it. You can have a replacement back in just a few days. You can also upgrade to something newer and better if you wish. There is a charge for out of warranty and upgrades but it is reasonable.

d4man

iTrader: (5)

Sounds like something maybe binding up in your transmission. Take it apart and inspect everything. Even if the teeth on 1 gear are cupped, that'll create enough friction to do what you describe.

Make sure the screws that hold the transmission halves aren't overtightened.

How hot does the motor get when its out of the car on a motor stand?

mtn bkr

iTrader: (19)

Check to make sure that your pinion isn't possibly rubbing on your gear cover as well. I was using Losi pinions years ago (they're wider than Robinsons) and couldn't figure out why my motor would get so hot and the car would lose power after 2-3 laps. Turns out the end of my pinion was rubbing on the inside of the gear cover. Might not be what's causing your problem, but something to look into.

bdenny

It does sound like you have something dragging in your drive train. It could be anything from the grear mesh at the motor to bad bearings in your drive axles.
I've had axle bearing issues on all my trucks and off road buggies. These are usually cheap and easy to come by and well worth a try. I'd start there and check everything.

d4man

iTrader: (5)

And check your gear mesh. Refer to the manual on how to set your gear mesh properly.

tony6187

HI JUST WONDERING HAVE YOU HAD ANY LUCK WITH THIS ISSUE.IVE BEEN HAVING THE SAME PROBLEM WITH MY MOTOR/GT7 IN MY TC5.HAVE CHANGED THE GEARING,MOTOR AND CHECKED THE DRIVE TRAIN (WHICH IS FREE AND SMOOTH) JUST GETTING FRUSTRATED BUT DONT WANT TO WASTE MONEY ON A NEW ESC IF THERE IS AN OTHER EXPLANATION.ANY HELP WOULD BE GREAT