1. Ask questions. Share your knowledge. Register TODAY!

OS .21 TM Engine

Discussion in 'Traxxas Revo' started by akadi, Dec 10, 2011.

  1. akadi

    akadi RC Newbie

    Hi guys,

    This is my first post here. I hope yo guys can help me out on this.

    I just purchased an OS .21 TM to replace my late TRX 3.3 in my 5309 REVO. I will run it with the supplied revo manifold and the stock resonator pipe. I will also install an ST racing 3 shoe aluminum clutch, and will run 16/36 gears. I have a stock of traxxas 3232x plugs which I will use. I also use byron 20% RTR gen 2 fuel.

    I have the following questions:

    1)what is the best way to break in this engine? The manual suggest 30 degree s lean turn every tank. I read else where to heat cycle it. Which is better? if its heat cycling, which is the best heat cycling method?

    Currently the temps are in the 70s during the day.

    2) Shall I seal the backplate and carb neck before running it?

    3) From your experience, is there anything that I need to know about this engine? what to look out for? what not to do? etc..

    Looking forward for your replies...

    Thank you
  2. RC-Sakke*

    RC-Sakke* RC Newbie

    1) I would use the Traxxas brak in procedure, then tune it following O.S.'s manual.

    2) I think they should be sealed enough well at the factory.
  3. Phins Fan

    Phins Fan Hardcore RCNT User

    1) You can ask 10 guys this ? and probably get at least 7 different answers. Most people would suggest the "heat cycle" method. Its what I have done to all of mine. My only variable to this method is I continue to run very rich for about the first 1/2 gallon before I really start tuning for power. Just my .02

    2) It could be a Novarossi powerplant. It wouldnt matter. Whenever you purchase a motor or even an entire vehicle (kit or RTR) I would suggest you go thru EVERY nut and bolt as the assemblers always forget to use threadlock here and there or forget to tighten down screws here and there. The extra time you spend on the vehicle now will save you alot of time when your driving your car and your friends are asking you for extra bolts/nuts that they lost from thier vehicle.

    3) Never used OS powerplants but let me know how they work for you!
  4. willswheels

    willswheels RCNT Rookie

    I put the OStm in my revo and it is alot eazier to tune.Idles really well.I broke it in real eazy.Did not start leaning it out untill i run 3 150cc tanks thru then 1 hour increments to lean it out over the next 7 tanks before running it hard.I preheated the motor to 180 degrees before i first cranked it and it made the EZ start fire it rite up.Revo has been doing backflips ever since.Good motor!
  5. 2revo1maxx

    2revo1maxx Hardcore RCNT User

    I would do what this guy did^^^^^
  6. Extreme RC Mods

    Extreme RC Mods RCNT Vendor!

    I agree with this guy ^^^
  7. akadi

    akadi RC Newbie

    Thanks for your input guys. I was beginning to loose hope of getting any answers here!

    ---------- Post added at 7:26 AM ---------- Previous post was at 7:21 AM ----------

    When you ran your first three tanks, how much throttle did you apply? was it continuous, or like the trx's press/release? also for the next tanks, how much throttle and for how long?
  8. 2revo1maxx

    2revo1maxx Hardcore RCNT User

    I would do the first three similar to the traxxas method. The real trick to those first few tanks is the pre-heating. New engines are very tight and it's not good to fire them up cold.
  9. jk6672

    jk6672 RCNT Addict Veteran


    What do you guys do to pre-heat?
  10. Metalhead Matt

    Metalhead Matt RCNT VIP

    Hair dyer or heat gun.
  11. Rfjelectric

    Rfjelectric RC Newbie

    I also got this engine and plan on breaking it in today. How has it been running for you?
  12. 2revo1maxx

    2revo1maxx Hardcore RCNT User

    Os engines are well known for running very good.
    They hold their tune better than a 3.3 or other cheaper engine.
Draft saved Draft deleted

Share This Page

Users have found this page by searching for:

  1. os21tm break in

  2. os .21 tm review