• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

Trx 3.3 problems

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
R

rccks

RCTalk Talkaholic
Messages
437
Reaction score
12
Points
148
Location
Connecticut
RC Driving Style
  1. Bashing
  2. Racing
I have a TRX 3.3 engine in my T-Maxx classic, it has about 1 1/2 gallons of 20% Top Fuel run through it. I ran it one day, it ran great, the next day i went to start it and it would not stay running itself, about 2 seconds after i took my finger of the starter button it stalled. after a couple more tries it just started to blow gas out of the exhaust. i tried leaning and richening it on the HSN, and i put a fresh glow plug in it(McCoy MC59 plug) but none of that worked. :surrender


I'm going to break in my rebuilt 2.5 for now, and i wanted to know what everybody thought of this break-in method
https://www.rcnitrotalk.com/forum/showthread.php?t=42716&highlight=heat+cycle+break
 
- Try priming well while starting (hold finger over exhaust for 2sec or so)
- Are you sure the EZ-Starter battery is fully charged and is strong?
- Make sure your idle is set so the carb is atleast 1mm open.
- Make sure theres no leak in the gas line / pressure line and all the gas is flowing in properly.

If that doesn't work try reseting needles to factory default and try again.
 
i did that before and it didnt work

i went to break in my 2.5 and the same thing is happening. my exhaust might be cracked, would that cause a problem?
 
tried putting a revo exhaust on and it still isnt running..... i am extremely confused right now
 
What happens exactly. Does it turn on and run without sputtering for 2 full seconds than turn of with a clicking sound? The engine should still run without the exhaust on so I dont think its has anything to do with that.

-Double check that your fuel tank is totally sealed (lid pushed in with rubber seal, no cracks)
- Make sure your pressure line is connected to the exhaust and tank properly withought slits or any clogging of in the pipes.

You arent using the same carb on both motors are you? Make sure that theres no striping at the HSN and the entire needle and pipe connection is in tight and sturdy.
 
Last edited:
tank is completely sealed, all lines are good. it idled for 2 minutes and then shut off, no sounds or anything. i tried to start it and it wouldnt start. when it idles it just blows gas out of the exhaust.
 
jay3 said:
You arent using the same carb on both motors are you? Make sure that theres no striping at the HSN and the entire needle and pipe connection is in tight and sturdy.
Click to expand...

It's probly just too rich, try adjusting both needles and increase the idle speed a lot. If you get it running you can just turn it down.
 
different carb, its all cleaned out, and at factory settings, tried adjusting it but then it wouldnt run at all...
 
It sounds like you had the same problem I had but when you tip it on its and have the end of the exhaust pointing to the ground does gas run out, because if it does then your motor is more than likely shot. If it does that to check and see if it is blown take the cooling head off and the backplate which is behind the ez-start system, then move the piston all the way to the bottom of the crank case and stick a zip-tye in were the exhaust comes out then take a pair of needle nose plyers and spin the shaft and it will push the sleeve up far enough were you can grip on to it (be extremly carefull not to wreck anything incase the motor is still good.) The next step is you take a needle nose plyers and disconect the connecting rod and pull the piston out if the piston pops up past the top of the sleeve you motor is blown. If in that case it is I recommened the traxxas engine replacement plan just look on the traxxas site and it will tell you what to do.
 
the 3.3 is pretty new, and i just rebuilt my 2.5 which is having the same problem
 
rccks said:
when it idles it just blows gas out of the exhaust.
Click to expand...

I guess you mean 'fuel'?
If that's the case, you need to set your needles back to factory specs, then lean the LSN 1/4 turn.
Make sure your glow plug is bright. Leave the igniter on for a minute after it starts. If it keeps running after you remove it, good. If it quits, you're still to rich and can lean it another 1/8.
Keep us posted.
 
And I doubt it will, since you replied 12 minutes after I posted.
Given the time to leave your computer to go outside, and then come back in and reply, you spent less than 10 minutes to reset the needles, check the glow plug and try to start it.

Good luck.
 
Your definately too rich. go back to factory settings and go 1/8 lean on the HSN. If that doesn't work then your LSN is probably too rich as well. In which case you will also need to go 1/16-1/8 lean as well. Think of your needles as a clock and lean out 1 hour at a time after you get it running to tune for performance
 
none of this is working, i messed with it for about 20 mins, i got it to run for a minute without any fuel coming out, then it stalled and when i started it back up it started blowing fuel everywhere. the engine is not shot because i have the same problem with my 2.5 i just rebuilt. i might take it to my LHS and have them look at it....
 
It kinda sounds like there is an air leak somewhere. Try taking the fuel tank off and submerging it in water and blowing through the fuel lines. If you see any air bubbles then you have a cracked tank. I know that when I cracked my tank the crack was really hard to see. If nothing else works than I would definetly just take it into your LHS.
 
If the exhaust is cracked, then you've definitely wrecked it hard enough to cause an air leak somewhere so that is a possibility. To me it sounds like it is way out of tune. Also, you might want to full with it when you can spend more than 20 minutes with it, as these things can take time. If all else fails, get yourself a nvak HV pro brushless system, a few LiPo batteries, and a nice conversion kit. You will never have to worry with the carb again, and it will better fit into your 10 to 20 minutes time schedule.
 
benjamin420-gas tank is not cracked, i took the tank off of my revo and hooked it up to the maxx and the same thing happened.

charlestheman-not my exhaust, i put my unused revo pipe on it. it might have an air leak somewhere though... i have re-tuned it like 6 times from factory settings. and i would of spent more time working on it but it ticked me off and it would have a lot more problems than it already does!

and no electric conversion! I'm a nitro person!:banana:
 
Last edited:

RC Builds

Back
Top