New 4.6, but getting discouraged...

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tjstinson

RCTalk Basher
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  1. Bashing
First, I am somewhat new to the RC hobby, but I would not consider myself completely green. I am still learning, but I have maintained and had success with a nitro buggy for months.

I just bought a Savage X 4.6 new. Got it started and the throttle trim was dialed full and before I realized what was going on, I busted the spur gear. I thought I might have ruined the engine, but it has good compression and seems fine. Bought all four spur gears that the hobby shop had and replaced the stock one. Have a perfect mesh now and I have learned a valuable lesson to always check the settings on the controls before I start the truck.

I finally got two tanks during the idle break in and two tanks of limited and gentle figure 8 runs.

I just started tuning the HSN...

PROBLEMS AGAIN:

1. Was probably a full turn or more on the HSN (done in 1 hr increments at a time, of course) and though the engine was definitely getting dialed in using 20% Traxxas fuel, I was no where close to standing up (new black top in 40 degree ambient temperature).

2. Checked the temps after the fuel run. 280 degrees!? I was definitely doing some WOT runs, but nothing extreme and I still felt the HSN needed turned in at least a 1/4 or more turns based on the turns and response I was already getting. So high temps and I know that temps are relative and subject to many different factors, but being a new truck and knowing that I was not getting the throttle response I should expect, and the truck has yet to take the front wheels higher than a 1/2'' from the ground, what am I to do?

2a. I could ignore temps entirely and risk damage to the engine, but perhaps high temps and little torque response is typical during big block break ins? Should I just put the temp gun aside, focus only on smoke from the exhaust, throttle response, and just trust the visual and audible clues and risk the warranty while ignoring HPI suggested temp suggestions?

2b. Has everyone had to patiently wait beyond the initial break in to get the desired performance they expected from a stock Savage X 4.6? After watching HPI's 2009 big block break in video and seeing a wheelie after just a few HSN adjustments I had the expectation that I would have seen similar results. I spent a whole tank and many HSN adjustments and never got close to a standing truck.

3. I just went through one tank during the tuning phase (to be clear: I have had only five tanks of fuel through this Savage to this point- two at idle, two during figure 8s, and one tuning the HSN) and suddenly the back plate just spins the wheel to the roto start and does not engage the piston.

3a. I have read on forums that this happens if oil or lubrication gets into the one-way bearing. I certainly believe this the case as after letting it sit I got it started again. It died immediately (I just popped the throttle a bit too hard once it started and it died). I tried to start it again and the spinning returned. Let it sit a day and I could engaged the piston with the roto start, but when I gave it throttle, it would not move. It then died and the back plate went to spinning once more. It is as though it dries out after sitting and once I can use it effectively again it gets lubricated within (though I have sprayed different cleaners at the opening over the past couple days) and won't engage the piston. Does that mean it is not broken since it CAN work after a period of sitting? I have a new plate coming from HPI, and I have not removed the stock one, but I suspect this is a lubrication issue?

4. At what point would you just say forget this? I want the Savage. I want it to operate as advertised. I don't want to alter it any more than necessary until I have made myself familiar with it enough to make alterations that are specific to my desired performance based on it's stock stage at full potential. I haven't seen that potential yet (I got it over a week ago and all of these things have hindered me from even getting it tuned). I guess what I am asking, without changing stock parts, are my expectations realistic? Shouldn't I be seeing wheelies, tuned engine within a reasonable temp, and a back plate that performs more reliably? All of the issues I have had are so far from what I was expecting when I spent months researching my next purchase and settled with this one. I am very disheartened, annoyed, disappointed, and certainly the laugh of all my neighbors who watch me pack my gear to the street just to watch me pack it back in moments later. I have spent $800 in parts, tools, the truck, and accessories, and a week later I'm sitting here wondering if I am the fool.

I am open to all suggestions and support you can offer. I know this is lengthy and might seem like "another guy that should have just gone electric and/or got over his head-noob!" I hope you can put aside your feelings and give me the straight talk based on solid experience. I appreciate all your words or efforts to help. Thank you.
 
In my experience with the '13 savage x, I experienced some of the same issues. First for break in I used Byrons 20%. Stay away from Traxxas fuel as it has way too much oil and can cause excessive heat and might be your starting issue for the one way. The manual states tomshut down at 250°. I found this to be very low. My truck isnt happy till around the 270° mark. Every engine is different.

If you are experiencing predetonation you are too hot or lean. I had issues with the one way. The tiny spring inside the connecting rod actually broke into pieces. You will need part number starting pin/ pressure spring 1433. It might be different now as hpi recently updated part numbers.
 
Ok, what this sounds like to me is you set the throttle trim back to neutral where is should be! But now your experiencing your carb slider not opening all the way, causing a lack in performance, and then did what I did with my first nitro engine, which was lean it out till I got some type of performance out of it.

What I would do is reset the HSN back to factory settings, so your not over heating the engine, then adjust your throttle linkage to the point where the carb opens up fully. This could require trimming the steel rod in the linkage! Alternately the larger the spur/clutch bell combo you use will move the engine farther away from the stock position, but I doubt you'll get what your after that way. It's a better idea to adjust your linkages first, rather than start playing with your gear ratios off the hop.

When you start changing gear ratios, you will always have to adjust your throttle linkages to accommodate the different position of the engine.
 
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Also dont be surprised ifnthe stock servos take a crap. Both were replaced on my truck after getting it. The throttle servo was sluggish and wouldn't pull the throttle all the way open. Its a great truck after you iron out the kinks.
 
Engine break-in is always hard on glow plugs, try a new plug. If your having a starting issue you can always get a few hotter glow plugs to see if it helps. While you have the engine out, make it a point to clean off your starting shaft, and OWB then reassemble it.
 
Thank you, everyone!

I'm getting a lot of feedback regarding the Traxxas fuel lately, but I have a hard time trying to point at it specifically for expected performance as my understanding of compression and combustion causes me to believe that, despite the quality of lubrication, the combustible fuel is still present. It may cause varying engine temps and temp expectations, but the response should be somewhat similar- at least the horsepower, though it might be muted, should still be present enough to lift the truck. A big block two stroke of this size should lift a 20 lb truck easily regardless of the quality of oil if the percentage of combustible matter is of the ratio of ignition. It, then, leads me to lean on the side of patiently awaiting the engine to break in, run in different ambient temp or wait for engine to heat up before observing critically, the glow plugs are a large factor, and/or the engine setup is not correct.

Either way, I GREATLY appreciate the feedback and will take ALL of it into consideration.

Thank you very much!
 
+1 on checking to make sure the carb is opening all the way, plus I would make sure your slipper clutch is tight. I tighten mine all the way down with no problems. A savage x 4.6 should pop wheelies easily. As far as your owb, if its the type with the sleeve and set screws, loctite and tighten the set screws. Hope this helps. The savage is a great truck but most rtr rc vehicles have a few bugs to work out.
 
+1 on checking to make sure the carb is opening all the way, plus I would make sure your slipper clutch is tight. I tighten mine all the way down with no problems. A savage x 4.6 should pop wheelies easily. As far as your owb, if its the type with the sleeve and set screws, loctite and tighten the set screws. Hope this helps. The savage is a great truck but most rtr rc vehicles have a few bugs to work out.
When I installed the new spur gear, I tightened the slipper clutch TIGHT. I know the manufacturer tightens it down and then backs off a 1/4 turn (or so), but I was told to get it tight and leave it. That is what I had done. Thanks for the info!
 
UPDATE:

This whole process... sheesh! I called HPI, they have a reputation for good support, but I do not care much for the firm policy on repairs. I had to send the truck to them so that they can look it over and fix it. The spring for the pin inside the roto start housing was deep into the piston. I didn't even want to mess with it anymore. It is new and I want new to operate as new. I shouldn't have to make my own repairs before I have even enjoyed it. Arthur (the manager) said they would look it over, tune it up, and make sure all is right with it. I understand this policy 30 or more days past the date of sale, but I have only had this a week.

I argued that a replacement makes the most sense when the item will be in transit and repairs longer than the length of time I have owned it, but he was annoyed to argue that the policy was firm and would not change. He said they would "make it right". I would argue that they are "fixing a wrong." Making it right is rather relative and certainly does not favor this particular customer.

I informed Art that I understand that customers can, and often do, lie about the condition of their truck when they call support, but when they look it over and discover, as I KNOW THEY WILL, that the truck is spanking new and that I have done EVERYTHING by the letter, then I am a customer that was inconvenienced by poor product manufacturing. I am the one out $500 and nothing to show for it for the next 2-4 weeks. How is that "making it right?" If they stood behind their product and really empathized with their customers, an immediate replacement would have made more sense in a product only a week old.

No matter. Just venting. I am sure everyone has a varied opinion on HPI support and I am even confident that most of them have a positive experience. Mine is a bit unique in that I have had two big issues, but have yet to fully break it in.

So, the truck is currently in transit or just arriving at Great Plains, IL and will be repaired. Art said they would fast track it and have it back before three weeks. I'm not all that confident, but I am sure they will discover that I have been more than honest. Hopefully when I get it back it will be tip-top. If not, I guess I have to go through this nightmare all over again. I don't know at what point they just refund my money or if that is even a possibility.

Thanks for the help. I hope I will look back on all this in a couple months and just laugh. So far this hobby has been a costly one and with little to show for it.
 
Nitros are picky beasts . They're also very sensitive to minor things.

Most of what your dealing with seems to be related to tuning and adjustment. Nitros are a constant tweak.

I've had similar issues with mine. Switching fuels and getting better at tuning fixed the issues.

Hopefully HPi can get you sorted, but be aware it isn't plug and play like electrics tend to be.
 
NOPHIX:

I appreciate your help, but I have owned nitro before and I'm not interested in the electric side presently. I had one many years ago, but nothing like the new modern electric vehicles today. I have tuned on nitro and have been successful in nitro. My issues are specific to this particular HPI Savage that have very specific issues.
 
UPDATE:

After more correspondence with HPI and monitoring the repair ticket online I have a greater appreciation and positive view of their support. They are making things right and I have had improved experiences with them at Hobbico. I am new to much of the RC hobby in general so I consider this a learning experience. In my ignorance I had a different expectation on product support and how it must be carried out, but going forward I realize that it makes a huge difference when one is aware that when they buy from their local hobby shop that they are essentially purchasing from a third party and that if an issue occurs it may mean your hobby shop can do little to correct it in respect to the warranty.

I wanted to clarify for anyone reading this thread that I did believe in HPI's support and that it was a huge factor in my purchase. After dealing with them I have an even greater respect. Treat them with kindness and reasonable expectations and you will receive better support than you would otherwise and certainly better than what I have received from other RC companies.
 

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