petedam

I recently got into nitro R/C with an HPIRS4 EVO+. Took me a week off and on to get it tuned right, but now it runs sweet.

Got tired of trying to find parking lots big enough so I went and bought a Savage XL RTR. Did the break in procedure then began tuning with HSN, etc.. It never got the point where it would run as well as the RS4 does. Sometimes it would reach top end, sometimes it would sputter, sometimes it would hesitate at half throttle and bog down sometimes hit 3rd gear sometimes wont get out of 1st. It was never anything consistant. Acouple of times it would run decent, but still have trouble mid-range and while it USEDto do wheelies when I first started tuning, it barely gets one wheel off the ground from launch.

I've gone back to factory settings and restarted tuning many times. One day I was doing high speed runs through the grass and it seemed to be doing fine, still not 100% smooth but it would reach 3rd gear at least and what seemed like top end. Then something strange happened. All of sudden the throttle would start acting up. I'd go WOT and it would rev up and downlike a rev limiter in a real car. Even 1/4 throttle and the truck would try desparately to get out of 1st gear but never could.

So for some reason I decided to try out the electronics from my RS4. I switched the crystals and the truck was back to normal!Still not 100% yet, but it was going through all 3 gears again and finally Iwas able to do some tuning atleast without it reving up and down!

So things were fine till today. I could never get smooth mid-range or that wheelie popping action off launch, but Ifigured there was still some fine tuning to be done. Took it to the park today and the same damn thing is happening!I give it a littlebit of throttle to get it moving but before it even goes into 2nd gear it starts sputtering and choking then revs, if I give it full throttle it revs up and down never getting out of 1st gear!I also noticed that when I left it sitting there idling without touching the brake, the throttle linkage seemed to be moving back and forth a mm or two.

So what the heck is going on?Are the crystals really responsible for the erratic behaviour of my truck?And if so, why do they keep failing on me? I can't tune this damn thing if Ican't get any consistancy. I'm not impressed at all with this truck as it's been nothing but problems from day one. Hopefully someone can shed some help as Ihaven't even been able to go off-roading with it yet!

SAVAGEJIM

Welcome to RCU and sorry to hear your truck is being ornery.

Which radio comes with the XL? The TF3 or TF4?

Well, if you did everything to try to remedy the problem (charge batts, even change batts, check wires, set trim, fix linkages, etc.), then the problem for sure is the radio and/or interference.

The RTR radios are really pretty junky; they are only intended to get you started into the hobby. I strongly suggest you get a mid-grade 2.4GHz radio and I can guaranty you that virtually all of your throttle woes will go away.

petedam

Thanks for the response.

It comes with the TF3.

Yes I've gone through the list.. new batteries, set trims, etc.

I know these radios aren't the best, but it should atleast last long enough so that Ican tune the thing!

I'm hoping maybe there is something else going on and that buying a new radio will be last resort, I've spent enough on this hobby already!

SAVAGEJIM

I know what you mean. And the hobby does liberate you of cash, even if you buy the cheapest stuff possible.

I agree, the TF raios should last you longer. I have a TF4 and I bought that used. It still works.

Call HPI, they will warranty and replace your radio. Just describe everything you did; I feel you have a very strong case to get a brand new replacement TF radio.

SLAYERDUDE

I agree with SavageJim.
HPI sent me an upgrade 4 channel RX for my XL.
And it was because I ground the antenna wire off from sliding down the street on the lid doing wheelies.
So it wasn't even a defect and they could have told me to buzz off.
Instead HPI gave me a free upgrade.

Call them, be very nice to the person you talk to and they will likely be nice right back to you.
Get your ducks in a row, be calm and don't call them with an attitude and make it sound like you know exacty what you are talking about.
When I called them the guy told me I sounded like I knew what I was doing and even replaced things he shouldn't have like the engine mount I broke from jumping...
In the end HPI sent me over $200 worth of free warranty parts in that one shipment.

Just some friendly advice.

SLAYER

petedam

Wow, sounds like HPI actually cares about their customers. That's nice to hear these days.

I'm not angry at anyone, just frustrated that I can't figure out what's going on. I like to know what the problem is instead of just trying to replace it, I'm stubborn like that.

But from what I've read so far, it sounds like the servos are also too weak for the truck so I was thinking it might just be better to buy a whole new system.

That won't really answer my questions but at least I'll still have hair left on my head. Does anyone know what would cause the crystals to fail? Other than water, which there wasn't any at the time,I don't understand how they could fail for no reason. And not only once, but twice!

rclugnut10

My Feedback: (1)

sounds like an air leak to me and the headache that can be AM... if its the servo twitching, to see if its just annoying am bleh, put your savvy or your TX in the hands of a buddy and get them around 15-20 ft away (just to be super sure, its should go away after like 5 or so) and see if the twitching stops if it does than its just AM annoying ness and avoid getting it too close to you or get a new radio 2.4's can be found for $80 from tower, the only differance from it and your stocker will be the 2.4 as far as extra's...

as for servo's towerhobbies makes some nice servo's for cheap, the ts 150 for steering which will run you about $40 and they also have a high torque for around $20 that'd be good for brakeing, tho you just just the steering thats in tehre for throttle duties...

the lug

wolfie1

I had that same problem with mine when i got it i changed the throttle servo and it made a huge difference but wasnt 100% then tried in another reciever and havent had that problem yet, hope that helps

petedam

Well I bought a new crystal set, popped one into the TF-3 radio that came with the Savage and the other crystal into my RS4 receiver.

Long story short, the car went full throttle head-on into the curb and suffered some pretty severe damage, I don't even know why I bought that thing, off-roading is so much more fun and the XL actually drives OVER curbs!

So I put the crystal into the Savage's receiver and went off to the park. Not a single glitch! Still needs a little fine tuning (I messed with the med. spd. needle before I knew I wasn't supposed to).

So there ya have it. It was the TF-3 radio all along. Thanks for your help guys. Now time to save up for a 2.4 system!

SAVAGEJIM

Great to hear you have your radio woes sorted out!

I am not sure why the cystal was bad; maybe it could have been damaged either form shock from being hit or maybe just from a bad factory batch.

But I totally agree, going 2.4GHz is the next step and you wise move. If you can, I strongly suggest you get a a Futaba FASST 2.4GHz, if not that, a Spektrum.

petedam

Beats me!The factory supplied TF-3 must've been doing something to the crystal because it ruined two different sets.

My LHS has the Spektrum DX3.0 DSM so I was thinking of going with that to start. Am Icorrect in assuming that the stock servos plug right into theSpektrum receiver?

SAVAGEJIM

Absolutely! The will fit that RC and any other RX or any other Pistol radio on the market.

Also, I think the Spektrums all come with 2 servos along with an extra RX. So, even if your SF servos are junk, you can replace them with the Spektrum servos.

I have not shopped for radio gear in such a long time; I do not know what deals radios come with today. Ask you local RC store and they can tell you all the additional gear you get when you buy a radio.