fried esc or motor?
 

We've been running my lads rtr mad rat on a 2s lipo. Recently the car is a lot slower than it used to be. There are no mechanical issues and I know the lipo Is good so its either motor or esc. If I get my volt meter on the battery I have 8.8v. If I put the car on full power I am only seeing 7.4v at the motor terminals. Is a 1.4v drop through the esc normal or have we cooked it?

8.8v for the lipo is not right, should be max 8.4v. Also is it brushed or brushless?

cooked motor or esc
 

Hi there ,i did the same with my lrp system,it started to slow down and then stop completely after 3 minutes but with full charged lipo,i cooked the motor as i seriously over geared it for bashing in the park,under gearing doesn't help either,i gear mine to run at about 70 f temp after 6 mins(23 kit spur)it melted all the insulation and the windings,see if you can borrow another motor and compare,also check your gearing by asking on the forum (what esc ,motor and gearing you have).hope this helps.

Hi, its running the standard brushed clash motor that comes with the kit with a 21t pinion I think. It's also the standard surius esc. There are no obvious signs of overheating like smells or burns.

Hi. The voltage loss is perfectly normal, and this is shown as heat in any electionic product. IE- the ESC.

The stock motors are absolute pants, and really aren't designed for longevity. And i'm 99% sure that the motor is the issue.

That LIPO reading doesn't seem right though. Are you measuring the voltage with a DMM or an analogue meter?

Btw- Just for your piece of mind; my motor is now showing signs of slowing down, and it's only about 1 1/2 hours of runtime old. I intend to dispose of the electrics and buy an EZrun brushless system though so i'm not fussed.

All the best,

Damian

Give it (the motor) a good spray with motor cleaner or break cleaner then re lube the bushes at each end with a light oil like sewing machine oil :)