• 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

Revo issues

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

Blue_Ghost

RC Newbie
Messages
11
Reaction score
0
Points
0
RC Driving Style
  1. Racing
Hi, Well ill get down to the problem:
My Revo 3.3 #5308 is having some running issues.
A: It seems to be tuned correctly-however, when i increase throttle it high revs and there seems to be very little power going to the wheels.
B: The Revo engine is running a bit hot, also it produces the right amount of smoke.
C: the idle varies, when placed on wheels it will crawl away on idle after 1/2 tank.
I'm new to Nitro Rc's.
Thanks for the help~
 
1-Check your spur gear for worn teeth and make sure it's adjusted correctly.
2-Go back to factory carb settings and re-tune.
3-If it is still pulling away at idle then you'll need to remove the engine and check the clutch spring.
4-You may also have an air leak. I've not had much experience with that so someone will chime in and help there.

This should help you get started narrowing it down.
 
i agree with charlie on this one,

if that doesn't work. come back, cuz once you rule those out, it will be easier to diagnose the problem.
 
Ok... I actually checked the slipper clutch and found it was to loose. I returned the HSN and LSN to stock settings and then tuned from there.
ATM: The engine sustains no low idling, however it runs hot, and wants to cut out at high rpms... I'm guessing its to lean so i should richen the mixture?
 
It does sound like it could still be lean or you may have an air leak. Look at the fuel line to the carb when it's running and see if you can see little air bubbles? I'm really not real experienced with air leaks. What temperatures are you reaching? The 3.3 seems to run best between 240 and 270f.

Just a side note. When you're tuning make sure your engine is up to running temps before touching a needle unless it's absolutely necessary to keep it running.
 
Last edited:
around 300f..... I think it may be to lean, The LSN is whats getting me.. ill adjust the HSN then do a WOT then adjust the LSN... WOT... and then adjust the idle screw... Now i assume i should adjust the HSN on high rpm shut off's... I did check for an air leak and saw no signs.

also, i may have waited to soon to adjust the needle settings... forgive me still new to nitro, after messing with the needles after about 1-2 minutes id have to adjust again..
I'm thinking I'm too lean b/c when i start the motor and do a run within 10-15 secs it will feel to rich so ill lean out.... Sorry... Ill let it run idle to acceptable temps first.
 
Last edited:
Allright, from factory settings.
1-warm up to running temps.
2-start adjusting hsn in 1/8 turns. Pay close attention to power gains and when you stop getting a difference then back off 1/16 to 1/8.
3- adjust the lsn at 1/16 turns untill you have nice throttle response and smoke trail.
The lsn is tricky and you should really pay attention to how it's effecting your tune when messing with it.

If you're not comfortable with the lsn then leave it at factory. You wont get wheelies but you'll save your mill for another day.
 
it looks like it was 2 things,
1-I was adjusting the needles too soon.
2-I had the LSN or HSN to lean.
I'm curious, if the settings are to lean, i was told i would get little to no smoke, however, during my tuning runs i did have a decent amount of smoke.
Thanks a bunch for the help-
I've been told alot of things on how to proper tune your engine, i think this time ill listen more to the manufacturer recommendations as well as yours. thanks~ :D
 
I've allways been able to get a good trail of smoke on my Traxxas mills even when too lean. They're a little more finicky than other mills I've messed with so you really have to pay close attention to how your rig reacts. Glad I could help you get on track with it.
Charlie
 
what fuel have you been using on your 3.3. i always found my 2.5R and 3.3 TRX engines to be harder to tune and stay running with Traxxas top fuel.

not saying anything bad about it but i always used o'donnels and got alot better performance out of my TRX engine.

but changing fuel ( as i was told ) requires a mini break in session so it accepts the new fuel.

but whatever fuel you use. there should always be a decent trail of smoke out of the pipe. and monitor those temps cuz being at 300* + for any long period of time will seriously lower the lifetime of your mill.

if you did buy this mill from brand new you can always call up traxxas and they will send you a new or one fix the old one. but if your bought it used. you can exchange it for a brand new 3.3 for a decent price IMO

hope that helps
 
Reference the set up cd

I too went through a fair amount of tuning tribulations. The found the hsn tough to set because it was hard for me to see/hear performance changes, one, i'm a noob, two i'm on one noisy a$$ed airfield. I went till it was so lean I started get high end cuts then fattened up a 1/4 turn and it did well. i didn't like the whole fuel cut to engine cut timing method of the lsn so I played and tweaked and played and tweaked some more until I had the throttle response and eventually idle performance that I wanted....when it was all said and done...say 2 hours later, i reached down, pinched the line and in 2-3 seconds the motor sped up and quit. Moral of the story..use the book. Using that knowledge today, I had a buddy with exact same car have a broken clutch and didn't recognize it, thought it was tuning, had his tuning all messed up. Fixed the clutch by pulling a new hook in the spring and put it back together and went out to tune it up....leaned out hsn till it cut, backed off 1/4. While it was warm, started it and used line pinch technique to adjust lsn and was done in about 15 minutes with one screaming nitro and crazy throttle response....flipped over in fact...a feat i've yet to accomplish with mine. Yet another reminder that fine tuning was an ongoing process.
 
if your running in cold weather your gonna see a trail dont mistake it for smoke from richness.. i run lean and still have lots of smoke in cold weather..
 
I'm using Blue Thunder racing fuel at 20%, I am running in cold weather it stays around 40-50 atm. I read the traxxas mills do produce smoke even when lean.. I've got it running well right now, it is abit on the hot side, around 270-290.
 
that still might be a bit lean...cooler temps should find you running closer to 220 - 250 tops...fatten it up a bit and see if it still holds the same power. More fuel equals more oil, cooler temps and longer lasting mill...to a point. If you are not at exactly peak settings, it's better to be on the fat side of ideal than the lean side.
 
OK, if you watch the big boys tune, they very rarely, if ever, pick up a temp gauge. Your traxxas book pretty much nails it on the HSN setting. Start from factory, make several high-speed passes to get it up to operating temp. Then, start leaning little by little until you stop noticing an increase in performance, then, fatten it back up just a tad. Go in 1hr increments. 3.3 are touchy and you'd be amazed how little of a turn makes a huge difference. When you're adjusting the LSN, let it sit and idle after it's been running for a little while. Count 3 seconds and give it full wood for a second or two. It should rev right up and blow a nice little cloud of blue smoke. Make sure it's a nice even prrr, it's ok if it 4 strokes a bit. Do this a few times. Then try a 10 second count. You should get a slight bog along with a pretty decent amount of smoke. If the engine wants to rev up and down while at idle, you're probably too lean on the HSN. Richen it up just a tad. This is common. Don't worry about temps though. Seriously, if it's blowing nice clouds of smoke and running fine, leave it alone.
 
Thank you, today after a few runs i adjusted the hsn abit more rich, i got a decent cloud of smoke and no bog or power loss, over the past 2 weeks I've learned that the 3.3 is indeed sensitive to minor adjustments. to sum it all up, i let the engine warm up to running temps, ran it through a couple wot's and checked the needle/performance based on the rich/lean setting..... The high temps were caused by the lean mixture... i 1/8 turn counter-clockwise and it purr'd..... i finally dialed it in gentlemen.
Again thanks so much for the input and help provided, ill pass this info to my nitro buddies so they can learn a thing or two....
Blue~
 
Glad our combined efforts could help. but before you pass on too much, are you going to wind up racing these guys? Just food for thought. I'm all about helping out a buddy, but as I recently experienced, it's a real kick in the junk to help them tune theirs only to find out you did a better job on the competition than your own....:hehe:
 
Rock and Roll! As soon as you get away from tuning by temp, you can really start to get the hang of it. I think the Traxxas book even tells you to stay away from tuning by temp.

Glad she's dialed in, bro.
 

RC Builds

Back
Top