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Rervo 3.3

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Damn_Yankee

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I know this maybe an open ended question, but here tis:

Traxxas 3.3 with about 10 tanks through it. Will not run without power to the glow plug. Reverted back to stock needle settings, fires up a/EZ start, btu quits as soon as the button is release. Runs fine with a seperate ingnitier attached (rich of course) Suggestions/Ideas?

Thanks in advance
 
Replaced the glow plug, and started to slowly lean the LSN. I've got in a full turn, and had to add some trottle trim, it made a little difference, but wouldn't idle more than a few seconds w/o the ingnitor. I've leaned it another 1/4 turn in small increments with the same result. Anything further, or still keep leaning?
 
Turn your HSN at least 1/2 turn in.
Set and leave the throttle trim all the way down. Any adjustments to the idle while setting the LSN should be done with the idle screw.
You need to blip the throttle and drive around to clear it every time you adjust it. If you just keep turning it down you'll seriously overheat it. Go too lean and you'll burn out the plug.

https://www.rcnitrotalk.com/forum/showthread.php?t=60832
 
Thanks Rolex. One thing I've not been doing "You need to blip the throttle and drive around to clear it every time you adjust it.". Temps have not got above 172 F yet. I'll give it another crack tomorrow.
 
Rolex, I can't tell you how much I appreciate you patience. I leaned out the HSN 1/2 turn, turned the trim back to Zero, I think now I can get her to "High" idle for a minute, but idle is high (rollin w/o brake). I've backed the idle screw out a 1/8 turn, didn't make a difference. I'm scared to make any other adjustments at this point for fear of loosing what I have. I've got smoke at idle, and blimping the trottle keep everything going. But, if I blimp the trottle open, she'll quit. Temps are 180 or so, 197 is I keep messing with it. Advise?

---------- Post added at 7:15 PM ---------- Previous post was at 7:12 PM ----------

By the way, I sealed the motor, and when she quits, no high idle, just stops. If I pick the truck up at idle (moving forard) revs pick up quickly. Hope this helps!
 
No problem going above 200. 240 is a pretty good spot for those engines.
If your idle screw won't slow the idle you'll need to check the throttle/brake linkage. You also want to make sure the trim is full off so your braking doesn't kill the engine.
 
If the idles "hangs" while rolling after a speed run then you need to richen the hsn a little bit. It should always sound a little high but not so the truck wants to roll away. If it gets into that real low idle and quits then the lsn is too rich or the idle too high.....or both.

Your looking for a nice clean idle that can sustain itself for over 10 seconds at about 190-250 degrees. If you punch the throttle after those ten seconds it should take off without delay.
 
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God, I feel like a school child in shop class, and I'm 45 thinking something is wrong with this engine. I fixed the trottle linkage, and now can adjust the idle with the adjustment screw. Now I'm back to the same thing, she'll fire, idle at the correct RPM, but quits immediately after removing the igniter. Leaned the LSN a little at a time, running small circles blimping the trottle, pull the igniter and dead. Should I go back to stock settings and start over? I thought I was pretty close last night, but now think I've lost ground. Can't get past step one to have her idle for a minute. I do not want to throw the towel in, but Geeeez louies. This is the hardest tuning issue I've had in my short career with nitro. Advise?
 
Don't give up.
Make sure you have a fully charged ignitor every time you try to start it. All the time trying really takes a toll on it. If you can get it started, slowly give it fuel while holding it off the ground. Once it starts getting warmed up, give it more throttle and good blips. Lean the LSN till you get a very quick response, then see if it will run without the ignitor.
 
Definitely warm it up before tinkering with anything. Like rolex said you may have to do whatever it takes to make it run a few minutes until it warms up. Don't be afraid to turn the lsn in a 1/4 turn, if it makes the engine run.
Low speed tuning is 7/8 of all that's tricky about tuning. The lsn and idle gap have to jive just right, because the engine only wants a certain amount of air and fuel at idle. You may also be hearing what's known as a 4 cycle idle, which is a low idle that sounds correct, but it's not.
 
Thanks

Again, appreciate your help. Taking a night off from it tonight, recharge the batteries. This has been the most tempermental engine yet (out of three), so I'm frustrated. I think I'm decent at tuning, but when you can't get past the first step, I start to question things. I gave up on this engine once, and bought a picco .26, with great results. There is only 3/4 of a gallon through the 3.3, so I'm pretty sure it's my lack of tuning knowledge. I'll give it another shot in the next few days. Thanks.
 
Ok, started this evening, got the temp up to 205, and tweecked things a little. I'm three teruns out on HSN, one turn out on LSN (93 degrees and humid here in Al) With the ingniter on, no trottle and lifted of the ground, idle is high w/wheel turning. Slowly giving trottle and letting off, revs increase with lots of smoke, and the only way to bring her back down is to hit the brake. If I blip the trottle open, she quits. Pull the ingniter off, and revs slowly die, and she quits. I'm not going to give up as long as your guys continue to offer advise. Agian, at a loss here.
 
We'll stick with it till we get it running.
You can still lean the LSN a little more since you're are not even near an overheat yet.
The more you lean it the higher the idle goes, so you'll also need to lower that while making your adjustments. Again, make sure the throttle trim on the Rx is all the way off.
 
Really appreciate your patience. Trim is off, and I feel like I have all other bases covered. Engine is sealed, and its a new roller, so fuel lines and tank are all new. So, if I'm hearing you right, start again and get the temp up, and back the idle screw off a bit, and continue leaning the LSN (while making sure the clean her out before making adjustments)?

---------- Post added at 9:02 PM ---------- Previous post was at 8:57 PM ----------

BTW, found out tonight that enough time running with the igniter on will loosen the ignitor enough it will pop apart (hehe)
 
This morning's tuning attemp didn't go much better. Currently waiting for igniters and EZ start to recharge. Managed to get the temp between 225 and 240, but still will not run without an igniter. Current state is after starting and lifted off the ground, easing into the trottle rev's pick up pretty high by themselves, and a WOT blip kills the engine. Remove the igniter and she dies. What next?
 
Suspect

Wondering now if I may have a low compression situation. I know its not apples to apples, but I can turn the 3.3 over by thumb and feel the resistance. My Picco Maxx is next to impossible to turn over the same way. I pulled the head, and no signs of "trash", but it turns over by hand (or thumb) a hell of a lot easier than the picco. Something to ponder?
 

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