Top M249 Motor Spark & Smell?
 

Well, I'm stumped really. Just today I received a new battery 8.4v 3500mah NiMH and I just test fire the gun without the buttstock and I noticed a odd smell and when I took look at the motor and pull the trigger again signs of sparks was shown inside the motor. Then I try with my 8.4v 1700 mah NiCad and produced the same result, motor sparks inside and smell.

However, everything is running smoothly, fuse is fine and the wiring is fine is it just the motor dying? Could someone just educate me if this is normal for all motor to spark every time the trigger is pulled? If not, time for me to get motor replace or gearbox replacement..

It's running fine! Well from what you say, as no one else is there to check it right! But it does sound fine !

I'm not sure at all, sounds normal when it shoots no awful sounds, burning smell could be the dust or the greese some people had stated on other threads, but sparks in the motor? I don't want my 2k MG going up in flames.. lol

the burning smell is normal to most electric motors in machineguns, the sparking means you need a new motor, your armature might be bent and its not worth fixing lol

lol How could the armature be bent? Well, I have to lower replacement gearbox then... argh..

yeah, sparks are not good.. lol. like thudnercactus said, time to get it replaced.

The sparks can also indicate that the brushes need to be de-bured.The comm,has seated into the brush and you can just use a file @ a 45 deg. angle remove the high edge and use a comm stick and resurface the brush,give it a shot of some motor spray (can buy at R/C store!) and clean out the motor.Much cheeper than a new motor! Some sparking is normal thow,depends on how much? Motors do get dirty from all that Carbon and copper flying around.How old is the motor/how many rounds? The comm stick also has an end to clean & polish the comm. as well as the brush.Last comm stick I bought was $6.00,motor spray $8.00.Might just do the trick!
I'm not sure about a bent comm,could happen I guess.The motor probley would not turn over if it was bent that bad.Sparking more to do with wear pattery and current being pulled through the motor.ie if you were using a M130 spring insted of a stock one,the m130 would need more power to turn over and draw more current than a stock set up.I would just try and clean the motor as you were saying theres no other problem you'v noticed with the gun other than the smell(usally alittle bit) and some sparks(witch is also normal to a point).Next time you use a drill,look in the back were the comm, is,you'll see lots of sparks! Have a good one!

Thanks, for the help. But since I have no experience on electronics at all I don't want to touch the motor at all, but the gearbox is wored when I bought from another user. However, I do remember that some dust metal (When I was filing my M249) the dust metal attach itself to the motor and I try my best to get it out of the motor, I guess some were left behind in it.

The TOP lower gearbox is old design and the entire motor is solder with the wires and attached to the switch and its bitch to take out, but everything else is fine which is good.

I know BC local gun doc isn't available anymore, or at least the well known one.

+1 for what Death March mentioned. Any electric motor will spark to some degree. The particular motor that TOP uses will spark quite a bit. Cleaning the brushes and commutator as mentioned above will reduce it quite a bit if done properly. It's a very simple job to do. The other nice thing about TOP 249's is that a lot of RC car motors can be bought that fit in the mechbox easily. As for cleaning out the metal filings from the motor, I'd recommend using automotive brake cleaner. Just go to town on the motor with some and it'll be clean as a whistle. It will remove any grease and loose debris, so you may need to regrease the mechbox when you're done.
The smell is quite normal as stated above. New motors will smell a bit when they're first broken in, and can smell later on if they encounter a higher than normal load or grease or oil get in them. Good luck with your gun!

I used to be real big into rc car racing. You will always get a particular smell from your motor, you will always get arking as well, to take your motor apart if the com is really in bad shape, you could take it to a hobby shop and get it turned for 10 bucks. also about using brake clean to clean your motor, brake clean leaves a residue, only use electric motor cleaner. and put a drop of oil on each bushing once in a while.

Where you able to find a motor because I need a new one :p

So this is for anyone who has a problem like this and cannot find a single person to help you. I litterally searched every where but I did find a motor a Guarder high torque short type will mount on your gun but not the pinion head so you will need to swap them and make adjustments to place it in the right spot hope this helps those who have the same problems