I bought a Revo gremlin!

[mrbullz]

4 weeks old and this thing is possessed I swear! Broke in as recommended but I cannot get it right to save my life. On my second carb. Won’t go in reverse anymore and today it got stuck full throttle and decided to kiss a stop sign. What am I doing wrong??? Just ordered all new front end parts to rebuild her.

 

[easy rider]

First, buy the forward only conversion and do away with the contraption that comes with having a reverse on a nitro vehicle.

Second, check your throttle return spring. If this had come unhooked, it should have at least slowed it down once applied during the run off that occurred.

Check to ensure your throttle arm that’s bolted onto the motor, its t getting hung up in that spring or linkage.

Whatever it is, before you start it again, make sure that part is working correctly. And ensure your carb is returning to the idle stop once the throttle is released. If it doesn’t you’ll never get it tuned. So, make sure that is right. If it’s not, adjusting the linkage stops is how to fix it.

Third. Set your idle gap. Then set your hsn at 3.5 turns out from closed. (Assuming the break in is done. If not, set it to 4 out and break it in to your preferred method.) Set your low speed needle flush.

Don’t fool with the idle screw throughout any of this. Remember, you are building a great tune around the suggested idle gap.

Once idle gap is set, start the car. Get it to temp. Then do your wot runs for the hsp needle tuning. As you begin tuning you are coming from a rich setting. If your carbs are anything like the ones I’ve tuned, on a good compression motor, you’ll hit your hsn tune between 35-40 minutes leaning from your 4 out starting point.

As you lean the hsn tuning, if it increases idle higher then needs be, just richer the lsn to the desired rpm’s.

If the truck won’t run doing this, you’ve got a leak so e where. My advised starting point on the carb should work to get you very close to start with. If it doesn’t, get it running and post a video. These guys will get you pointed in the right direction trouble shooting it.

 

[mrbullz]

First, buy the forward only conversion and do away with the contraption that comes with having a reverse on a nitro vehicle.

Second, check your throttle return spring. If this had come unhooked, it should have at least slowed it down once applied during the run off that occurred.

Check to ensure your throttle arm that’s bolted onto the motor, its t getting hung up in that spring or linkage.

Whatever it is, before you start it again, make sure that part is working correctly. And ensure your carb is returning to the idle stop once the throttle is released. If it doesn’t you’ll never get it tuned. So, make sure that is right. If it’s not, adjusting the linkage stops is how to fix it.

Third. Set your idle gap. Then set your hsn at 3.5 turns out from closed. (Assuming the break in is done. If not, set it to 4 out and break it in to your preferred method.) Set your low speed needle flush.

Don’t fool with the idle screw throughout any of this. Remember, you are building a great tune around the suggested idle gap.

Once idle gap is set, start the car. Get it to temp. Then do your wot runs for the hsp needle tuning. As you begin tuning you are coming from a rich setting. If your carbs are anything like the ones I’ve tuned, on a good compression motor, you’ll hit your hsn tune between 35-40 minutes leaning from your 4 out starting point.

As you lean the hsn tuning, if it increases idle higher then needs be, just richer the lsn to the desired rpm’s.

If the truck won’t run doing this, you’ve got a leak so e where. My advised starting point on the carb should work to get you very close to start with. If it doesn’t, get it running and post a video. These guys will get you pointed in the right direction trouble shooting it.

Thanks!!! Amazon will be bringing parts next week so hopefully I can be back up and running with this one next week.

 

[mrbullz]

Well. Let’s see if we can get Humpy Dumpty back together again.

 

[Lostinthewoods86]

Pick up one of these and get rid of the track as carb

 

[mrbullz]

View attachment 184074

Pick up one of these and get rid of the track as carb

That’s on the list. How bout I just come grab one of those. You look like you got extra.

 

[Lostinthewoods86]

That’s on the list. How bout I just come grab one of those. You look like you got extra.

Just send me the revo

 

[easy rider]

View attachment 184074

Pick up one of these and get rid of the track as carb

X 2

 

[mrbullz]

After getting everything all back together, turns out the one-way bearing was bad so I bought one of those. Got it started got it running was doing small test laps in the driveway slowly and the damn thing took off towards my wife’s Corvette at full throttle with no control. I had to step in front of it and stop it with my foot because I really didn’t feel like dying today. I finally called Traxxas support and the guy was super nice. He called it a “Demon Runaway Revo” and their tech department will go through it with a fine tooth comb. They sent me a shipping label and I boxed it up and sent it back to them and he said it will be repaired. He said one out of every few hundred will just run away. So after spending entirely too much money on parts, I at least get the satisfaction of knowing that it was not my fault (this time). I am very impressed with Traxxas customer support. And I was also right about it being possessed.

 

[easy rider]

Dang!!!!! Sounds like a problem I had once with a Traxxas tmaxx rx/tx. I re binder the original and it did cliched twice in a couple seconds and I slammed on the brakes and got it shut off before it run off. I swapped the rx/tx out for a new one and it’s been great ever since. Low power shut down has been flawless.

Hopefully they’ll get it fixed for you. Hang in there. It’s a fun car when you get it dialed in.

 

[mrbullz]

Dang!!!!! Sounds like a problem I had once with a Traxxas tmaxx. I swapped out for a new one and it’s been great ever since. Low power shut down has been flawless.

Hopefully they’ll get it fixed for you.

Sounds like every once in a while one gets through that’s not perfect. The one I bought used runs flawless every time I start it. After talking to them, I’ve got a good feeling that they’ll get it right.

 

[easy rider]

Sounds like every once in a while one gets through that’s not perfect. The one I bought used runs flawless every time I start it. After talking to them, I’ve got a good feeling that they’ll get it right.

I edited my original post to clarify I swapped the rx/tx and not the whole rig.

 

[Weezel]

@mrbullz and others with Opti-drive

I'd put money on the Opti-drive is the culprit. There has been many discussions about others having the same problem. I would bypass the Opti-drive altogether. It's not needed. It's main purpose is to prevent the shifting of fwd to rev or rev to fwd when it's moving. Just remember to not shift unless it's stopped. I removed mine and never had an issue since.

 

[mrbullz]

Got the email from Traxxas that the truck was done. They replaced all the broken parts but didn't replace whatever it was causing the d**n thing from running away..."We tested it and couldn't replicate". They even put a new engine on it (not sure why). I took it upon myself to order a new optidrive and reverse servo and those will go on before I ever start it. From all the guys here and what is all over the interwebs, I am 99% sure its the optidrive. I need the failsafe cause I'm not the brightest bulb in the box and I find that I use the reverse more times than I should. Either way the new Savage X will be here Friday so I reckon I'll have some fun with that one till I break it.

 

[Weezel]

It's funny how they think a quick bench test is going to replicate issues.

I hate for you to be believing you need the opti-drive for a throttle failsafe. There is already a failsafe in the receiver. If you're talking about not being able to shift directions when moving then you're opti-drive does protect from the accidental shifting.

Enjoy the Savage. I've always wanted one but never was able to get one. Maybe now that HPI is back to producing them I might just be able to now. Just need to save my penny's!

 

[mrbullz]

The savage ate up the last of my overtime pennys. So it’s back to work I go. Going to take the Savage with me on my next out of town trip to play with.

 

[easy rider]

Don’t give up on that revo. And, start coming to terms with, diving in and fixing it yourself. It’s your car. You gotta do your own wrenching to learn the car. It’s frustrating at times but, it’s how you learn to build the best nitro for you.

I certainly understand why you sent it back. I would have too. But, if it isn’t fixed, I’d demand a refund if your warranty is still good.

If I may suggest what I consider to be words of wisdom. Ditch the opti drive. Ditch it. Ditch the reverse with a forward only upgrade. Ditch the two servo system and put a single good servo on it. And, while I’m a fan of Traxxas carbs if I’m the original owner, if raw, jaw dropping power and, a blazing top speed is your desire, buy an os11kr carb for it. Put some 3.8’s sledge tires on it and enjoy what is now one of the finest monster truck nitros you could build. I’d tell you to get a pull start but, I’m not so thrilled with them either at this point.

 

[mrbullz]

Don’t give up on that revo. And, start coming to terms with, diving in and fixing it yourself. It’s your car. You gotta do your own wrenching to learn the car. It’s frustrating at times but, it’s how you learn to build the best nitro for you.

I certainly understand why you sent it back. I would have too. But, if it isn’t fixed, I’d demand a refund if your warranty is still good.

If I may suggest what I consider to be words of wisdom. Ditch the opti drive. Ditch it. Ditch the reverse with a forward only upgrade. Ditch the two servo system and put a single good servo on it. And, while I’m a fan of Traxxas carbs if I’m the original owner, if raw, jaw dropping power and, a blazing top speed is your desire, buy an os11kr carb for it. Put some 3.8’s sledge tires on it and enjoy what is now one of the finest monster truck nitros you could build. I’d tell you to get a pull start but, I’m not so thrilled with them either at this point.

The 11kr carb is already ordered but on back order!! I have the other Revo that is perfect I may take this one and delete the opti and reverse. I dont mind fixing what I screw up. I love wrenching on things. I was only concerned with the electronics. We’ll get it right….. eventually.

 

[easy rider]

The 11kr carb is already ordered but on back order!! I have the other Revo that is perfect I may take this one and delete the opti and reverse. I dont mind fixing what I screw up. I love wrenching on things. I was only concerned with the electronics. We’ll get it right….. eventually.

Yep. That’s what I was referring to in addition to doing the forward only conversion. I was surprised they didn’t swap out the rx/tx. It’d be hard to justify swapping a motor instead from what you’ve described as the problem.

Hopefully your problem is fixed. Good luck.

 

[mrbullz]

Yep. That’s what I was referring to in addition to doing the forward only conversion. I was surprised they didn’t swap out the rx/tx. It’d be hard to justify swapping a motor instead from what you’ve described as the problem.

Hopefully your problem is fixed. Good luck.

That’s exactly what I was thinking. At least I got a brand new motor again.