• 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

3.3 upgrade

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
You will know its the spring if the wheels spin when trying to start. Could you just be too lean on the lsn or too big of a gap on the idle?
 
I'm not perfectly tuned. But close.. If i pick it up and let it idle down the tires stop turning. If I
Use brakes and idle down. It moves as soon as i let off brakes.
 
Thanks. I think I'm making this more difficult than it has to be. So if i reset hsn and lsn to factory settings then set idle gap to a small paper clip or a little less. Idle is done. Right??. Then fine tune
From there. I also watched a series from "squirrelzod" i think was the name. Both very helpful.
Its hard to tell if idle or lsn is off. There is a difference in sound. But if idle gap is set it would hafta be
Lsn. Well ill read guide again and start over. I hafta check clutch spring. Change mount and instal
Ez start.

---------- Post added at 5:55 AM ---------- Previous post was at 5:42 AM ----------

My bad.. "squirrelod".
 
Idle is fine tuned as needed as well. The "paper clip" gap is just to get you in the ballpark.

As for shutting the engine down, I either let it run out of fuel, or I stop the flywheel with a screwdriver.
 
I'm having trouble tuning my new 3.3. I have watched many videos to help and input from all of you. Thanks. I decided to check for leaks. Everything is good except where the main motor shaft comes through the block. Seems to bubble there. I checked another motor and its the same way. Is this
normal or do i have 2 motors with the same issue.
 
It's normal for the front bearing to leak on all nitro engines. I will not affect your tuning unless the bearing actually goes bad.
 
Thats Good news. I took out all needles and cleaned them along with the rest of the carb and engine. Also
changed spur gears and pegs. 3.3 rough on them. Need to upgrade when this one craps. I set all needles back to factory when lsn apart i set it flush with its holding sleeve. Then put arm on. About
1-1/2 turns out. Hsn 4 turns out. Idle gap a paper clip fits snug. Now after warm up it will hold an idle
For longer than 30 sec so thats good. right? It seems i should set the lsn next but actually the hsn is next. The lsn only affects idle and take off. Right. If i adjust lsn leaner my idle picks up. Is that ok? and to pull off a wot pass hsn needs to be about 5 turns out. Seems a lot. It was about 40 degrees yesterday are temps affecting my tune.
 
In 40° weather you'll need the hsn to be at least 5 turns out.
It should idle for at least 10 seconds without "loading up"....in other words, after 10 seconds you should have snappy throttle response with no hesitation.
 
It does have pick up but it seems as soon as i hit second gear it cuts out as if its to lean or to hot. I have an onboard temp gauge its reading around 230. Should i richen up more? i see a bit of fuel
On the end of the outlet now. As for my last post. Is the lsn supposed to change idle on a good tune?
 
No. I dont want it getting to hot. I do heat up the motor with a hair dryer to about 130-150 befor i takeit out.
 
It won't get too hot in 40° weather if you tune it right. 230° in 40° weather means it's most likely running too lean, that's why it cuts out in second gear.
In cold weather you have enough cold air coming in the carb to keep temps under control. I would at least keep richening the hsn until it starts to lose top-end performance, then you'll know where the sweet spot is.
 
Once i hit 5 turns out i thought that was to rich. So at 5 turns out I'm stil on the lean side of a good
Tune. Ill richen 1/4 go from there. Thanks!!
 
If it runs too cool with proper fuel settings, then wrap the head with something to get the temp to stabilize around 220-250. I find with proper tune in cold weather that the engine temp likes to dip below 200F unless I partially cover the head.

If you let it run too cold, the sleeve won't expand which will cause premature wear, then when it warms up outside, you will have weak compression.
 
I'm running those temps w/o covering the head. The next chance i get I'm going to try the nitro tuning and flow chart. That seems simple enough. Still confused on the " idle hanging in there". Gonna watch
Some videos of a properly tuned 3.3. To see what its supposed to sound like. If I'm running that hot as
2revo1maxx said probably to lean. Thanks.
 
Generally speaking, if you have a perfectly tuned engine running 220-240° on a 80° day, a perfectly tuned engine on a 40° day should run about 180-200° or less.....in fact, I've seen my engines run well below that on a 40° day without wrapping the head. That was when I decided to start wrapping them at anything below 50-60°.
 
If your running 240-250 without covering it at 40F outside, then that would be like running 280/290 on an 80F day, which would be lean. Which is why you should wrap the head a bit, then tune so the temps are around 240/250 as well.
 
In my experience with a wrapped head on a cold day, there's always enough cold air entering the carb to keep temps in check.

The bottom line is this: When in doubt, richen the needle until it's pig rich, then slowly work it back to a good tune.....simple as that :)
 

RC Builds

Back
Top