New Revo 3.3 Transmission and other issues

[flyingjackal456]

Ok, I've recently got into the nitro R/C thing, and have been on my own as two setup, breaking in, and tuning.

First thing: It is about 20-30°F right now, so I know the coldness might effect performance. I've already broken it in properly, but I can't seem to tune for power. I can't make it wheelie at all, and I know it's burning rich (I put it back to factory spec, and lots of nice blue smoke) but if I try to lean it out, it sputters after a decent run on pavement (overheat in dead winter?) a bit and it will never gain any power. I even replaced the glow plug and if it matters I'm using Byron fuel (20%).

Anyway, I've been running it mostly on pavement, then after break-in I ran it on ice and crusty snow or ice. I seemed to have stripped the reverse when I don't even use reverse all that much. I tore down the transmission and found the output gear (reverse) is plastic (unlike the forward output gear) and half of it is stripped clean. I'm starting to doubt Traxxas engineers already because of the rather odd places to put plastic instead of steel. after reassembly, the transmission now has a bit of friction (no binding, just steady friction and some extra gear noise).

Please Help Me
-Jackal

 

[Rolex]

If you just broke it in recently, chances are it's not broken in properly. Break in is all about temperature, expansion, and cool down. I don't break ANYTHING in when it's below 60.

The cold can also account for your broken gear. Below a certain temp, the plastic gets very brittle. That's another reason I won't run in the cold. The outside temp is also the reason it's difficult to get it to run properly.

 

[flyingjackal456]

ok, now what

If I wait for temps to go up, will I have to break in again, or can I just use it when warmer? I believe next week it'll be in the mid to high 50's, is that ok? I really don't want to wait until spring/summer to run the thing.

 

[Bryson]

Do your self a favor, if you dont use the revers loose it. Get a FOC and never look back. Solved alot of my problems. Also the motor, may just be to cold. Do you have a temp gun, If not get one it will help you with tuning alot.

Bryson

 

[flyingjackal456]

I tend to think the motor was warm enough (when you put water on the cooling block it sizzled immediately upon contact)

Thanks Everyone, how much can a decent temp gun cost?

 

[HILLFINGER]

Not trying to discourage you or anything but a Revo wasn't designed to wheelie, some does some don't. With the right tune and the suspension set properly it can be done.

 

[Elmerfudd]

Temp gauge runs about $25-$40. Hold it right on top of the head (touching it). If you end up a couple inches from it it will not read correct temp.

 

[Rolex]

Again, outside temps are a problem. If it's 20 outside and you maintain 230 degrees at the plug, you're obviously running it SO lean that it's being damaged.
If you really want to do it you need to wrap the cuff of an infant's sock around the head to keep it from cooling the engine too much. Tin foil will also help. Good luck.

 

[flyingjackal456]

ok, it's now warmer, the engine seems to run pretty smooth, except the low speed seems a tough rich, and the idle is too high.

I ended up stripping the reverse output gear and I bought a new reverse gear and cleaned and lubed the transmission (wheel bearing grease), all good now. The thing takes forever to shift into reverse, but shifts into drive almost instantly.

My clutch is slipping too much now (might be why I can't wheelie?), i never touched it before. I took the engine off to look at the clutch, it seems everything is good, so I wiped the bell clean and the friction material clean and put that back on. Then I decided to take the cooling head off to clean it up (very dirty and spilled after-run oil inside it). I noticed the piston is coated with brown oil (oil residue from fuel?) I wiped the piston head clean, and checked for play in the piston (no play which is good). I then moved piston to bottom (rotate flywheel) and a few moments later it was coated with oil. I then took off the header and cleaned up most of the oil inside the header. I then put everything back together, but it's too late for me to go annoy my neighbors trying it out again.

QUESTIONS:
Is the oil inside the header normal? Is that from burning rich? Crappy glow plug? Misfires?

Is there a way to check/adjust the clutch? How often to these clutched need to be replaced?

How to I align the spur gear? I tried the piece of paper thing but it didn't work, I ended up adjusting the engine until the gears weren't grinding, but still firmly grabbing.

 

[HILLFINGER]

It's normal to have some oil in the header.



Adjust the slipper clutch like the manual says when done, leave the 2.0mm hex wrench in the hole hold the wrench with one hand and try to turn the spur gear with your thumb,if it turns easily tighten more, if it doesn't turn at all loosen it a bit. You want to be able to be able to turn it with your thumb. Doesn't hurt to put some loctite on the nut and shaft to keep the nut from backing off also. I'm not sure how often you should replace them, I have been using the ones that came on the for over Six months.



I adjust my mesh to where when I hold the spur gear with my fingers and turn the clutch bell back fourth I can't feel any play between them. I you try to turn the spur with your fingers and it feels like it is grinding you need to back the clutch bell off a bit.

 

[flyingjackal456]

It's not the slipper clutch entirely, but the clutch inside the bell housing, It slips a bit, the after tightening the slipper just a touch, the truck has more power at the wheels. It was 58-63°F today, and the Revo is running smoother, I think it's running a bit rich. I ended up playing around in the frozen, melting snow, and the mud in between.

I drove it up a snow bank (plow trucks made a pile on side of road) and the stupid Revo slipped into a ditch (mini pond thing) Then it gurgled and a ran over to pull it out, after pulling it out it stalled. At this point I'm really hoping the thing will crank, I do not want to lose electronics, the engine, or servos. It cranked and I pushed the throttle a bit and got it to start up. I drove it around (gurgling a bit) and the water burned/evaporated off. Continued playing around, jumps and donuts in the snow, then shut it off. I then noticed the EZ starter motor siezed during my After-run maintenence. I forced the flywheel backwards to break the sieze and everything seems to work fine now. Amazingly, the servos and other 'sealed' components were all dry except the steering servos (they are exposed through the bottom).

 

[Gregtxman]

Change to a single steering servo and save the stock ones to replace the throtle servo if anything happens to it. You will not regret upgrading the steering. I just did and now I wish that I would have done it the day that I got my Revo.

In my opinion, it is the best upgrade for the money that you can do.

 

[Captain Chaos]

It took about ten tanks of fuel and some patience but my Revo 3.3 will wheelie on command when tuned to conditions.It seemed to increase in performance between tank 5-10.

Installed the JR 9100T and 9100s servos(probably over kill but WOW what a difference.It was good in stock form now its great control and power.).Picked up a spectrum radio.Stripped reverse also without hardly using it(dang opti drive stinks in my opinion my old TMaxx 2.5 still has reverse thing is 3 years old) installed the forward only and close ratio .

I am just a newb but these seemed to be the right upgrades to start with.I liked the wide ratio for general bashing but the close ratio works nice at the local track.

 

[Gregtxman]

I use the 9100T for steering and love it. Installed forward only kit and love it. hate the opti-drive.