Can these engines be saved/repaired??

[Kbabiasz]

I bought a 2.5 Tmaxx (4910) off ebay. It came with 4 motors. (2) Traxxas 2.5 motors, (1) Ofna 3.5 Motor, and (1) .21 Motor.

The car currently has one of the traxxas 2.5 motors on it. The Ofna is in near new condition. The other 2.5 and .21 motors are in pretty bad shape.

This is the 2.5 Motor. I cleand up the outside a bit and other then some gunk thats still on it, it came out decent. However there is still some debris on the inside of the motor. From what i can tell nothing is damaged. It looks more like water damage. The motor itself is not siezed, I can get it to turn with a Cordless drill, and when it does turn there is nothing that holds up, I however do no have the piston in it.

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This is the .21 Motor, its in pretty bad shape, but i do have all of the parts. The traxxas 2.5 above, looked like this when I got it and i was able to clean up the outside of the motor itself. The 2.5 cooling head looked like the .21 cooling head below, before i cleaned it up.

This one is in worse shape then the other.


I know i can clean up the motor's exterior and the cooling head, What i dont know is if I can clean up the inside. Yes, this one also turns with a cordless drill


**If these can be repaired without having to machine them, I may try to repair them depending on cost of parts**

 

[SteelCityNitro]

The 2.5 could use a rebuild, the 21 can go in the garbage

 

[Racer 1966]

Cost wise,neither look worth the effort to me. Better engines can be had for what the parts would cost to rebuild those.

 

[ThunderTiger]

junk them...............

be a pitty since one of them is an axial by the looks of it.

 

[Mickstix]

They're probably junk, but if your just getting into nitro, (or bored) lol.. I'd take a dremel with the wire wheel attachment, and go to town on the internals.. If all the parts are there, and the rod will come off the crank, clean em up and put it back together and see what it does? Hell, if nothing else it'll give ya some experience in how to rebuild a nitro.. Then if ya do get a new sleeve/piston or whatever else, in the future, you'll already know how to do it.. Who knows, might even run? Just dont do much to the piston or sleeve.. Hopefully they're not all rusted or scratched up? If they are, maybe try some 000 steel wool or white scotchbrite pad on them.. (But remember, they run off compression, so if the sleeve walls or piston skirt is all rusted or buggered and scratched up, they probably wont run) Good luck!!

 

[Kbabiasz]

They're probably junk, but if your just getting into nitro, (or bored) lol.. I'd take a dremel with the wire wheel attachment, and go to town on the internals.. If all the parts are there, and the rod will come off the crank, clean em up and put it back together and see what it does? Hell, if nothing else it'll give ya some experience in how to rebuild a nitro.. Then if ya do get a new sleeve/piston or whatever else, in the future, you'll already know how to do it.. Who knows, might even run? Just dont do much to the piston or sleeve.. Hopefully they're not all rusted or scratched up? If they are, maybe try some 000 steel wool or white scotchbrite pad on them.. (But remember, they run off compression, so if the sleeve walls or piston skirt is all rusted or buggered and scratched up, they probably wont run) Good luck!!

I have all the parts, And I have thought about trying a dremel, The 2.5, I think i can get going again, the .21 motor, Idk if i will be able to get it apart

 

[olds97_lss]

Well, heat and WD-40 usually helps.

Boca bearing removal/installation vids:

His accent is kind of fun... but the info is solid. I went through the process of taking the bearings out of 3 crank cases not to long ago using his methods and they pop right out with no fuss.

If they were mine, and I wanted to get them going, I'd clean them as well as I could to get any grit/sand/out of them then put them back together, lube the piston/sleeve and check for compression. If there is no compression, I'd pitch them... or keep them for parts.

If there is compression:
1) take them apart
2) replace the bearings with new ones
3) clean all the rust off the crank
4) get all the enamel out of the crank case, DA and q-tips
5) buff the exterior of the sleeves with a soft dremel wire wheel
6) soak the OWB's (if available) in DA and try to get them clean and rolling again
7) tear the carbs apart and clean every nook and cranny with DA and a q-tip, may require soaking. Clean the o-rings and lube them with associated green slime before installation
8) Lube the internals really well with ARO
9) Put them back together and seal them with RTV and give them a shot

Then again, I do that process periodically (except for replacing bearings) with my working engines just to keep them in tip-top shape after sitting over the winter.