Build Thread Two Traxxas Nitro Builds Modified Twice There Are 3 Now

[Dizzyotes88]

That Traxxas I put pictures up of, last night it got stuck in reverse. Not sure what is wrong other than the gear is burnt out. The servo is good because it works the regular throttle. So yeah. But I'm going to go play with at least 2 of the trucks with my kids.

 

[Dizzyotes88]

Correction, the servo is gone. Took 3 of my trucks to play with, with my kids including the one stuck in reverse. Today my buddy and I looked at the one in reverse. He took off the linkage to the servo and put it to forward with no issues. So that servo is toast. Luckily we have another one and a rebuild kit as well.

On the other hand we couldn't get the other one to run right after finding the air cleaner sponge in the intake. Got that taken out and it just wouldn't fire up. Nothing is blocking it. It's all cleaned up. Weird that it would do that though. Suck the actual air cleaner into the intake.

 

[monstertruckier15]

The stock shifter servo is crap. I have one that moves real slow. I will replace it with a better one. looks like you will be inspecting the motor after a filter malfunction. I never seen a air filter sucked inward.

 

[D3MON]

agreed to above, stock RTR servos are never strong or fast enough, i really liked the Hitec HS645MG in my T-maxx for steering and ended up just using them all over, and are well priced for the quality.
well guess this is difference in opinions, i would not recommend fuel filters, just take care when fueling to not get debris in the tank or fuel bottle. close caps, when not in use, wipe off dust etc, fuel filters are very liable to get an air leak (especially the really cheap ones) which will reduce fuel pressure making the engine run lean. also when they start gumming up, after sitting they will do the same thing by limiting the fuel flow.
when they work, they work great, when they dont, they really dont in my experience. by all means though definitely worth a shot, you may have betterexperiences than I did.
that is really strange with the air cleaner getting sucked inwards never seen that happen before.
the pre-load spacers are mainly just to tune ride height. the springs themselves are there to return the truck to ride height and the oil is the dampener. so if its feeling bouncy/springy like bad struts in a 1:1 car, get thicker oil, if its really stiff and slapping the ground and pogoing back up, use thinner oil. i found 40-45wt worked great in my T-maxx back in the day, but some liked thinner around 35wt, some were using up to 60.
if its sitting lower than you want, but still has good dampening and returns to its ride height acceptably (though maybe not the desired height) add a few of the preload spacers to get to the height you want. they arent necessary per se, though most i have experienced need some. the best height for power transfer is what is called "bones level" where the axles are flat to the ground, but for bashing a higher ride height is typically preferred because usually bigger jumps than racing.
all that is personal preference and what you want out of it though.
pretty cool noticed you have the steering servo skid plate and center skid plate in your pictures, nice mods there! careful with them aluminum bumpers though, they are not friendly if you happen to hit your ankle lol

 

[monstertruckier15]

The preload spacers are required to stiffen the suspension and adjust the ride Hight. With out them the truck will be dragging on the ground and bottoming out on jumps. shock weight oil is only go to slow down the spring rate. Useless for ride Hight. A fuel filter is a better solution to nothing. Any dust or floating debris gets inside the tank and can ruin a engine fast. I wish more manufacture's would put the filter inside the tank. Not make it a optional part. But I guess some people prefer to clean out the carb when it's too late. Cheap insurance. I have never has any more problems with running fuel filter with crap inside the carb leaning out my engines and ruining them. I will never buy new brand servo's again. The cheap china one's work great for me. My choice of servo compare to a Hitec 645MG. Servos Digital MG996R MG996 Servo Metal Gear for Futaba JR Car RC Model Helicopter Boa|Integrated Circuits| - AliExpress

 

[Dizzyotes88]

So, what glow plug should be in my 2.5 and in my 3.3? I bought a few from the RC shop and didn't pay attention to what they were before I threw away the package.

Also what can we do to get the motor to run cooler? We have a temp gun but can't find it at the moment but when it gets to hot it shuts off. So we would like to know what's the best way to get that solved.

 

[monstertruckier15]

Os #8 or traxxas 3232x Hot plugs A3 os. duratrax or os lc3 Open the high needle to 4-1/2 turns open. What % fuel are you using? traxxas will run with 14-18% oil lube. Temp should be around 235 degrees. If it's warming up and shutting down I suspect the fuel your using is causing the problem and or the piston/sleeve is gone.

 

[Dizzyotes88]

Ok it's not the fuel. I can only run 9% here in Arizona. We changed to 12% and 14% even with a new tune it wouldn't run. We get about 5 minutes out of it at the park. We get alot longer just on the street in front of my house. A full tank actually. So I'm guessing it's the tune or the piston/sleeve. We do have another 2.5 motor that we talked about switching out just to see. So perhaps we will do that and I'll post a update.

 

[monstertruckier15]

Check the pressure nipple on the exhaust to see if it's block. It could be low pressure? If using a fuel filter make sure it's tight and clean. The engine should run with 4-1-2 turns open. Check to see if when you prime engine fuel is spraying out of carb with air filter off.

GRIPE
Hot temperature you richen the fuel mix and lower you lean mix. You live in a warm climate so you should be rich. More oil lube is rich less oil lube is lean. Yet I live in cooler climate and run richer? The store told you is hog wash!

 

[Dizzyotes88]

No fuel filter. Nipple is clear. Not spraying out the carb. It runs, gets up to temp, and then as of 2 days ago up to today it dies. And we didn't change anything on the tune.

 

[monstertruckier15]

I suspect you got crap stuck inside the high need to the spray nozzle! Now you have to clean the carb out and add a fuel filter and hope the engine wasn't damaged? Every time you put fuel in tank Foreign debris is floating in the air and can fall in the tank working its way to the carb needle where it gets trapped restricting fuel flow until it dose exactly what it dose now. Starts up and then dies. This causes a lean run and can damage the engine. A fuel filter prevents this from happening. Catching the crap before it get to the needle and stops engine as if it runs out of fuel. Clean it out and go to go. No messing with the carb taking it apart and cleaning it.

 

[D3MON]

So, what glow plug should be in my 2.5 and in my 3.3? I bought a few from the RC shop and didn't pay attention to what they were before I threw away the package.

Also what can we do to get the motor to run cooler? We have a temp gun but can't find it at the moment but when it gets to hot it shuts off. So we would like to know what's the best way to get that solved.

2.5 and 3.3 should use O.S. LC3 or LC4, it is made by O.S. for those engines. id recommend the LC3, hotter plug is easier to start, and more stable idle.
really need to know how hot it is, if its getting too hot, (much over 270-280F) yo are getting boil back, fuel turning into a gas before it makes it to the engine and pushing fuel back out of the carb.
was this a new engine?
how is the performance and smoke before it does this? is it cutting out under acceleration? how much smoke under throttle are you getting? should be a steady stream of smoke out the exhaust.
as far as Monster's tuning advice above... just.. ugh...
cold air is dense, it has more oxygen, it needs more fuel to prevent a lean burn. (think of a cold air intake in a real car)
hotter air is less dense, doesn't require as much fuel.
ambient temperature, unless it itself is over an engines operating temperature will not affect the actual engine temperature once warmed up unless the tune is off

 

[Dizzyotes88]

Side note, for all the posts I saw about using RPM parts on a Traxxas. My buddy was running said truck that we are currently talking about and it lightly hit the curb with the tire and broke the upper right A arm pretty much at the tab where it attaches to the wheel part of the suspension.

Could have just been old. Sat around to long. Heat of AZ got to it. Plenty of things. But it's just a side note is all. We haven't bashed it. But we thought we could. Instead it broke from a very low speed bump.

 

[D3MON]

i never really had luck with the structural integrity of the T-maxx trucks, though that was with the pro15 model and the O.S. .18cvr years ago, and i hope they improved most of the areas i had issues with. RPM definitely help up stronger than stock for me, it is more flexible so will be able to absorb impacts better without breaking and saves strain on other components because it absorbs the blow usually. age and heat definitely over time does not take too kindly on plastics lol

 

[Dizzyotes88]

That's where it happened. My buddy is thinking of going with metal ones and upgrading the shocks. Seeing as the 2 of them on that side bent pretty bad.

 

[D3MON]

yikes, pretty surprised it snapped like that, kind of a long shot, but RPM does warranty their parts, though i dont know abut not being the original owner, and dont know if expires that i remember.
would really advise against aluminum a-arms, it will destroy the bulkheads and chassis braces. a-arms are a good sacrificial part, cheap part that is easy to replace.

 

[monstertruckier15]

I prefer the plastic arms as they are lighter. Metal adds more weight but it will protect the shock better.

 

[Dizzyotes88]

So I picked up another Traxxas. Revo to be exact. It's so quick! Anyways. Got one of my Traxxas that is dripping fuel from the front of it near the clutch bell and spur gear. What's the best way to fix it?

 

[monstertruckier15]

Replace engine bearings.

 

[Dizzyotes88]

Will an OS big block fit on Traxxas?