Tt02 going slower than usual

[Taylorjac5112]

Had my yaris tt02 for about a month now, running the sport tuned 540 with a high speed gear set. All running well until today, will not reach top speed..... No gear slipping either. Thought it was a dud battery but that's not the case either. Any suggestions on what it could be? Thanks.

[Pylon80]

Summertime causing the motor to get too hot? This will make it very slow. Can you touch the motor with your fingers without burning yourself? 

When I was running the sport tuned in mine I was geared 21/68 and I was using a small heatsink fan, just for reference/comparison.

[Taylorjac5112]

When it was running well yes, the motor was close to burning to the touch. Using the standard motor cover. Does this mean the motor is done?

[Pylon80]

14 minutes ago, Taylorjac5112 said:

When it was running well yes, the motor was close to burning to the touch. Using the standard motor cover. Does this mean the motor is done?

It will no longer be as good as new, but might still be usable once it cools down. I still run my first silver can from 5 years ago which used to slow down like this! I got a fan after that and enjoyed consistent performance with no fade. The bigger the fan, the better.

[Taylorjac5112]

1 minute ago, Pylon80 said:

It will no longer be as good as new, but might still be usable once it cools down. I still run my first silver can from 5 years ago which used to slow down like this! I got a fan after that and enjoyed consistent performance with no fade. The bigger the fan, the better.

I used it yesterday, had a good run no problems, then today this. I give it a few hours cool down time, and the same.... Could it be anything else besides what you suggested?

[Kowalski86]

36 minutes ago, Taylorjac5112 said:

Using the standard motor cover.

I'd strongly reccomend that you take that motor cover off, without a fan on it all that it does is trap heat and cook your motor.

If you want better cooling you just need a fan/heatsink combo. Make sure that the heatsink has vents in it so that the air can get through to the can.

[Taylorjac5112]

 

13 minutes ago, Kowalski86 said:

I'd strongly reccomend that you take that motor cover off, without a fan on it all that it does is trap heat and cook your motor.

If you want better cooling you just need a fan/heatsink combo. Make sure that the heatsink has vents in it so that the air can get through to the can.

Just had the motor out properly for a good inspection. When I give it full throttle then let off, it whines and makes a funny noise. I'm guessing from you've said I've cooked my motor. Thinking of getting the super stock tz in place of the sport tuned.

[Pylon80]

28 minutes ago, Taylorjac5112 said:

Thinking of getting the super stock tz in place of the sport tuned.

I would advise against that, since it will only get hotter and self destroy quicker than the silver cans.

Remember you will also need a smaller pinion to use the super stock since the KV is noticeably higher than the Sport Tuned.

[Taylorjac5112]

 

1 hour ago, Pylon80 said:

I would advise against that, since it will only get hotter and self destroy quicker than the silver cans.

Remember you will also need a smaller pinion to use the super stock since the KV is noticeably higher than the Sport Tuned.

What would be best, get another sport tuned 540 with a heatsink or fan. Then up the gearing? 

[El Gecko]

21 hours ago, Taylorjac5112 said:

When I give it full throttle then let off, it whines and makes a funny noise.

That whining or screeching is most likely the bushings going bad.

As the motor turns, the bushings wear out and lose material, so eventually the holes get enlarged and the tolerances increase, leading to vibration at certain RPMs. My Sport Tuned does the same thing unless I oil it before every run. Maybe try lubing yours and see if it improves? Sometimes they can just get dirty or gummed up.

It's a shame the ST motors aren't rebuildable, because it seems like the newer versions have a different bushing material that goes bad quicker than the rest of the motor. Mine is perfectly usable and looks brand new, but I don't use it because it needs extra attention every time. I've even considered dismantling that motor and trying to use the armature in a rebuildable can at some point, but I'm not sure if it's timed correctly.

I've heard good things about the Super Stock motors, and in my opinion you're on the right track there. Although they come with bushings too, it's much easier to swap them out for bearings, then the motor should last a good long while, and you'd only really need to be concerned with replacing brushes and keeping the comm in good shape.

With the SS motor, I'd go back to normal (not high speed) gearing with possibly even a smaller pinion gear than stock as suggested above. Your top speed may drop a bit, but acceleration will improve and the motor will stay much cooler, even moreso if you add a fan as also suggested above. Then once you have a good solid baseline setup, start increasing pinion size, but check temps and driveability as you go. The high speed gearset seems to be intended more for brushless motors.