My 3.3 motor is junk

[bbabb21]

Wow! I must be cursed when it comes to Nitro RC because I have 2 trucks a Revo 3.3 and a Tmaxx 3.3 and None of them run right now. I really don't care about getting my tmaxx up and running just yet because that is my through away truck, but no matter what I do I can't get my revo to stay running. I thought that I had an air leak so I have replaced the fuel lines, carburetor, new Glow Plugs the ones recommended by Traxxas, and the joints for the exhaust, I tour down my engine and and cleaned everything. There was no oil or gunk built up any where on the enging indicating a leak but no matter what I do or how I tune it after I make a couple of passes the thing dies. does anyone have any ideas? if I can't get it running I am just going to give up on the traxxas 3.3 and go to something eles.

 

[MotoGod]

Seal it if you think you have an air leak. What symptoms is the motor having? Does it just not start? Does it die at idle? Does it die at wide open throttle? More information will help us help you ;-) I run the 3.3 in my Revo wide open for 2-3 tansk in a row and it begs for more usually....pretty bulletproof motor for me thus far. Not as fast as I'd like to see...but definitely takes a beating.

 

[bbabb21]

My Revo dies as soon as I let off of the throttle. It runs great until I stop then it just dies and it takes a while to start back up. I have adjusted the idle screw everywhere from .5mm to about 5mm with the same result. I check the engine temp after a few high speed passes and it stays aroung 240 - 250 low end seems fine I just can't figure it out why it dies.

 

[MotoGod]

How is the smoke trail? How is the high speed setup on it? If you go from a dead stop to wide open....how does the motor react? If you set your idle to 5mm or so....that sucker is going to be SCREAMING at idle. 1-2mm should be PLENTY on the 3.3. If you start your Revo and apply the brake while standing still does the motor die? If so...check your idle again. When set properly the carb slide should NOT be able to completely close the gap. It should stop at your idle screw setting.

I had issues with my Revo at first, and then I re-tuned it a bit and now it screams (for a 3.3 anyway). It also runs @ 285 degrees pretty much full time. Any lower in temp and I have all sorts of strange issues with it. Bogging, sputtering, dying. Not sure if your 3.3 likes it hotter as well...but most I have seen like to run 265+ at a minimum...and most of those are more like 270+. If I get mine outside of the 270-290 range....I'm usually swearing at it because it runs like crap.

You may want to reset to factory settings and just retune it?

 

[bbabb21]

Been there Done that when it comes to resetting the factory settings. If you set your idle to 5mm or so....that sucker is going to be SCREAMING at idle. You would think that would be the case, but there is no difference between .5mm and 5mm. That is why I thought I had a carburetor problem but it is doing the same thing with the new carburetor that is why I now think I am getting air in the motor somehow but I don't see any signs anywhere. This is a funny motor and I can't figure it out.

 

[surgemaster1970]

How fresh is the fuel you're running , what brand of fuel is it and what percent? Trinity monsterbrew 20% works best in my 3.3's than traxxas brand.Do you have a fuel filter and did you clean that out?You stated you changed the carb...Did you change the o-ring thats in the carb mount plus the engine casting?The carb is sealed by 2 o-rings but I doubt you have an airleak.Air leaks would make it idle high , hot and erratic....How is the tank stone inside?The tank may need to be washed out plus you could have a bad fueltank o-ring on the filler cap..Are you running an OS8 plug? If not try one they run the best in the 3.3 for me.Try your LSN at 1 3/4 turns out and the HSN at 3 1/2 turns out and see how it runs because if you're opening the carb up that much to idle without any response then you're running too rich if the engine isnt screaming or you're running the wrong heatrange glowplug/bad fuel.Factory settings are 2 on the LSN and 4 on the HSN ..Good Luck hunting down the problem...

 

[hamz9561]

If you suspect an air leak, have you checked to see if the carb is sealing to the engine? sometimes a leak occurs if the carb isn't seating. Try to remove the carb body and put a little RTV around the carb body where it seats into the engine and reseat the carb.

 

[weezracen]

+1 on the factory settings! Sounds like it needs a good tune job to me.

 

[jasminemy4g63]

Try an os engine the 18 will bolt right up I believe the one you need would be the cvr or you could install a bb kit I have a few trxxas trucks including jato revo and t maxx and all the traxxas motors are garbage what happens is once they warm up to operating temp the motor shuts off and refuses to fire back up Good Luck Bro

 

[22yoshifan]

i had the same problem u either have an air leak in ur engine or a leak in your fuel tank :

 

[randall]

when u get tried of the 3.3 go with the .26max picco its bad ass you will need the ofna mount that goes with it with that it will mount right up and man does it put the 3.3 to shame

 

[vmswimfan21]

My Revo dies as soon as I let off of the throttle. It runs great until I stop then it just dies and it takes a while to start back up. I have adjusted the idle screw everywhere from .5mm to about 5mm with the same result. I check the engine temp after a few high speed passes and it stays aroung 240 - 250 low end seems fine I just can't figure it out why it dies.

pull your motor and look at the clutch for the dying when you hit the brake i bet the spring is messed up i had the same thing happen a couple times. as far as not running pull the pressure tube off at the pipe and blow into it and listen to your tank the oring might be leaking it will have enough pressure to run normal at low speeds but high speeds it needs to much fuel and dies. just a couple places to start.

 

[wildjokerracing]

o-ring on the fuel tank lid... just throwing that out there

 

[MyREVOis2fst]

the os engine is a nice engine, so i've heard. MY experience leads me to say that your engine needs a great tuning job, unfortunatly the 3.3 is a pain is the @#$ to tune. if you want a new motor, i would sugest the Dynamite .19 Mach 2. i just put into my revo adn you dont need any extra mounts(if you get it new, or with all the parts). but your glow plugs should be at the highest heat available and use 20% traxxas racing fuel. that setup seems to work the best for my revo.
any questions just ask me

 

[brendonz4]

does any1 always have problems with traxxas t-maxx 3.3

 

[BamaFan]

I have never had a issue one with a traxxas engine. They are about the easiest engine on the market to tune and keep tuned imo. If your having that many issues with a 3.3 a different nitro engine isn't going to change anything your still going to have issue's. To me it sounds as if you need to reset your throttle/brake horn and get it right. If your engine is dying when you let off or apply the brakes that has nothing to do with tune that means your throttle/brake horn is too advanced and is closing the carb. Try resetting your throttle/brake with the air filter off and hit your brakes and see if it is closing the carb you can do this without it running.

 

[frickenjoey]

With what part of the truck? The engine? For the time I was running the 3.3 I never had any real issues with it. Sometimes it likes to run on the warmer side which I never cared for much but other than that not really.

 

[nickbarb]

I have the same tuning issue with my 3.3 (not staying in tune) I had the same issue with the engine quitting on braking, it was a broken clutch spring. I will be going with the OS .21 TM engine. You only need to hold this engine in your hand to feel the difference. I really don't mind paying more if it means less problems and more run time. I did look at the Picco, but i have a very old and beat RC car with an OS engine and I've never changed the settings more than an 1/8 either way, and it still run"s like a beast.

 

[akadi]

my 3.3 didn't last more than 2.5 gallons. broken connecting rod and piston

 

[tmaxxfreek]

The last 3.3 i had took 8.5 gallons before i rebuilt it....it was still running fine when i done it i just got a good deal on the kit.......it always tuned easy and held tune great. I bought a used one to put on my Tmaxx and i hope i get good service out of it as well.