need help before the truck see's the trash can!

[rusty715]

could use a little help... bought a nitro rustler at a pawn store cheap. got it home and it ran, but constantly burned up plugs. Set it to factory settings (even though I'm at 5000ft and corrected elevation is typically in the 7-8000ft range). Fat at that point and leaning just enough to get some rpm and the plug burns out. Not fouled, wire burnt. I could make it run in the garage, but take it out and run it in the yard for 30 seconds and it dies when you let off the throttle cause the plug is toasted, even with the hsn at 3.5 turns out. I pulled the motor off and cleaned it up, thinking maybe the diaphragm on the carb had a leak or something, but it all appeared ok. Reset everything to factory settings, idle screw, hs & ls needles and it wont idle and when it shuts itself off the throttle/brake servo makes a click. The only way I can make it idle is to turn the idle screw all the way in! Just wanting to drive the truck for once I said screw it and tried anyways, even though the carb slide is 1/3 open just to idle. Took it out of the garage, hit the throttle twice and guess what? Toasted plug. My local hobby store sucks balls, and just wants to keep selling me parts and don't offer any help. I've spent over $100 I'm plugs just trying to make it run for more than 30 seconds! Just bought 4 more plugs and if I can't make it work with these I am sparing the next guy some trouble and will just throw it in the trash and put my $ into my dirtbike! Always wanted a nitro truck, now I regret buying it...

 

[Phins Fan]

Factory settings are typically your starting point for an engine that still needs break in. It is an extremely rich setting and you will probably find yourself fouling out plugs as they would be getting to much fuel. The fact you are burning the filament off the plugs is a bit concerning and where's the filament going?? Can you post pics of the plugs after they burn up? You can sometimes tell if you are rich or lean by the colors displayed on the plug/piston head.

Good luck. Sounds like you may have picked up a headache. I live in 01011 if you end up trashing it. JK. But buying used there's many times where you just take over another persons headache as they didn't know how to tune or maintain to start with. Don't let it discourage you

 

[Rolex]

I can almost guarantee you that's it's just a simple tuning issue. Simple if you're used to it and extremely frustrating if you're not.
What's the temperature where you are. Altitude and ambient temp have an effect on these little engines.
I agree with Phins, above, that pics of your burned out plugs will really help us to know what your current settings are.

 

[tvjv2009]

Not sure if this will help. Just to tell you what I a noo b did.( When you said 1/3 slide setting to make it idle it reminded me of it.) I tore my 3.3 down and cleaned and sealed it. When I put it back together, I put the piston in backwards. with you not knowing what was going on with it before, it may be worth your time to take the back plate off and take a peek. The cut in the piston needs to be to the carb side. I read that they are imposible to tune if this is going on. Just a thought.

 

[Nitro4910]

even though the carb slide is 1/3 open just to idle. .

At 1/3 open your not even using the carb's idle circuit, your already into the High Speed circuit.

The Idle Gap should be about 1MM not 1/3 of the way open.
You need to reset it to 1MM and tune it from there.
The easiest way to set the idle gap is to use the shank(smooth part) of a #60 or #61 sized drill bit.
Put the smooth end in-between the carb body and the slide, then adjust the Idle Gap screw till the slide just does touch the drill bit.
Set the LSN so its almost flush with the inner ring but not below the edge.

Then set the HSN to 4 turns out from closed.
Tune from there with a warmed up engine, HSN first, then LSN, then tweak the HSN if needed.

Here is what a 1mm idle gap looks like.

Here's a good explanation on tuning.
https://www.rcnitrotalk.com/forum/threads/rc-nitro-engine-performance-tuning.102688/

Here's a good flow chart to print out and keep with you till you get tuning down.
https://www.rcnitrotalk.com/forum/threads/nitro-tuning-tips-and-tuning-flow-chart.60832/#post-537066