50+ degree stock Assoc. motor timing?

[b027]

I received a stock Associated Off-Road Stock Motor (Edinger label) in a misc lot of rc parts recently. the motor has been opened by previous owner and the end bell modified with new slots cut for the can tabs to be reattached with significantly advanced timing. to my eye it looks like the timing is at 50+ degrees -- see the pictures below. In the 2nd and 3rd images below, the motor mounting screw holes in the can are at 3 and 9 o'clock, and the can crimp tabs are at 12 and 6 o'clock (just under the solder tabs where the brush leads are attached). You can see how far the brushes are advanced. I didn't notice this when originally bench testing, except that the motor's RPM was higher than expected.

Have you seen motors modified this way and what are the effects? I understood this was much father then is recommended for even a stock motor. I assume the motor is at high risk over overheating with longer run times and higher gearing. any other concerns? it seems to be in decent running condition

Should I leave it alone? not sure i would run it, but the label is damaged so not sure i would keep it for a shelf build either. Any suggestions or thoughts welcome.

thanks! -B

[b027]

in looking around online I found one forum thread where stock motors timed to 45-47 degrees was discussed, so it appears this isn't completely unheard of, though it wasn't clear if there was a known consequence or risk. My understanding is still that it's pretty extreme for a motor, even a 27 turn stock... Definitely interested in any other experience with this!

[juicedcoupe]

Those motors with lots of timing were designed for short duration races, in fairly low load vehicles. They ran very hot and were rough on brushes and comms.

The tabs are already loosened on the can. Assuming that it isn't already trashed, I'd take it apart, freshen it up, and put it back to factory timing.

[b027]

Those motors with lots of timing were designed for short duration races, in fairly low load vehicles. They ran very hot and were rough on brushes and comms.

The tabs are already loosened on the can. Assuming that it isn't already trashed, I'd take it apart, freshen it up, and put it back to factory timing.

Thanks, that makes sense. Would an RC10 have been considered a low-load vehicle?

I was thinking to open the can and reset the timing as you suggest. The end bell looks pretty rough in some spots so hopefully it's not damaged too much!

[juicedcoupe]

Those motors with lots of timing were designed for short duration races, in fairly low load vehicles. They ran very hot and were rough on brushes and comms.

Thanks, that makes sense. Would an RC10 have been considered a low-load vehicle?

While I'm sure that people ran them in off-road cars, I'd probably consider those motors (~45°) as suited for pan cars.

Even if the gearing is correct, I can't see a motor like that working well in a dirty environment. At least, not over time.

[b027]

While I'm sure that people ran them in off-road cars, I'd probably consider those motors (~45°) as suited for pan cars.

Even if the gearing is correct, I can't see a motor like that working well in a dirty environment. At least, not over time.

got it - on-road use makes a lot more sense.

what is the consensus on best way to open up the tabs on a stock motor? I started to pry the tabs but am afraid of damaging the end bell further.

I found one reference online where it was recommended to strike the rotor shaft on a piece of wood to pop the end bell off (without brushes), but that also seems risky.

is there a "safe" way to do it?

[GoMachV]

Ive always plunked the shaft onto a table to pop the end bell off. Prying the tabs never worked well for me, usually ended up destroying the screwdriver. Since those tabs have been off before they are probably weakened a bit so it might not take much. They were never meant to be opened.

[RC10th]

Ive always plunked the shaft onto a table to pop the end bell off. Prying the tabs never worked well for me, usually ended up destroying the screwdriver. Since those tabs have been off before they are probably weakened a bit so it might not take much. They were never meant to be opened.

I always ended up stabbing myself with the screwdriver trying to pry open those tabs, lol

[b027]

Ive always plunked the shaft onto a table to pop the end bell off. Prying the tabs never worked well for me, usually ended up destroying the screwdriver. Since those tabs have been off before they are probably weakened a bit so it might not take much. They were never meant to be opened.

well i ended up trying it just now with another stock motor that was burned up. worked pretty well! only issue was just one side came loose and the other stayed locked in so i had to work that tab loose with a screwdriver. got it in the end though, with only minimal damage to the label, so not too bad for a first attempt!

I always ended up stabbing myself with the screwdriver trying to pry open those tabs, lol

i did exactly the same - definitely a challenge to use that much force in a small area. I was also trying to not damage anything cosmetically... or at least do as little damage as possible.

The other problem i noticed is i marked up the brush hood from levering against it with the screwdriver. maybe i'm missing something but don't see another way to get leverage on the tab?