Losi Will not tune!!

[benningtonr]

I have a Losi Aftershock. Completely stock
Bought it used, less than 4 tanks run through it, so I was told anyway.
Had trouble keeping it running when I first brought it home. It would start then I would take off, about 30-40 feet it would die. Tried richening it, finally got it to stay running. It was running ok, shifting fine, but the idle was a little high, ok a lot high. so I would bring it in and turn it down, then it stopped shifting. Now I have spent 2 solid days trying to get it right starting at ground zero (3 turns out on each) about 100 times. When I finally get it to run descent (it is still not shifting) It is so rich that it will die idling) I am trying to keep the temp down. I'll bring it in temp through the roof, I’ll richen it a 1/4 turn, run it bring it back in and it will not change. Finally it will die while taking a temp reading. And if I pull the filter off, it died due to flooding. Temps have been as high as 390's and I keep richening it and they will not come down. Thinking of rebuilding and starting over.

Any Ideas?

 

[Scrogg]

390F, it's toast. Buy a new engine

 

[benningtonr]

Lovely, thanks
But why wouldn't it come down, we ricened it to the point that it would die when I stopped the truck, and wouldn't start.
Also we are driving the truck on a large open grassy area

 

[MotoGod]

Make sure your temp gun is reading correct. I had a scare with my OFNA when it was reading 380-ish...come to find out my temp gun was over 100 degrees off. lol If your temp gun is reading correct....you're pretty much SOL though. 390 is just enough to fry it all.

 

[benningtonr]

Ok, temp gun is brand new, seem to be right.
I am worried now though, I have a brand new t-maxx I am going to break in this week. is it wrong to run on a large grassy area. I was just doing laps, holding it wide open and slowing down making a u-turn then back again. Will these things handle the long rpms? No jumps or anything yet, just 3-5 sec WOT, then back repeat as necessary.

First nitro vehicles, very new. but I did stay at a holiday inn express last night.
But seriously, i have done a lot of reading, I drag race full size cars.
Race late model stock cars for many years. So I am not new to engines.

 

[MotoGod]

Mine was brand new as well, and 100 degrees off. Boil some water and temp it with the gun. Should be 212F if I remember correctly?

I'm fairly new to the Nitro tuning arena as well, and what I have found is that running in grass raises my temps quite a bit from when I run at the track...on both my OFNA Buggy and my Revo 3.3. At home while tuning my OFNA was running @ 260-280F while just burning laps in the front yard. Grass....1 acre....WFO back and forth just like you. When I got to the track, same engine, without a re-tune was running 212F. Revo was @ 30 degrees cooler at the track as well.

As far as the engines handling the RPMs, they should be just fine. My local track has a 200 - 300 yard straightaway where everyone goes WFO down, and we're holding it for a good 5-6 secs and revving the piss out of these little motors ;-)

 

[benningtonr]

Ok, good.
I am not racing, just want to have some fun. I got them because when I go to the drag strip we have about 2 hours of down time ( I like to get there early)
these are just to kill time.

LOL, 1000 dollars for toys to kill time, go figure

I have been reading alot about tuning,
Is it normal to richen it so much then not be able to get it restarted. or is that because the engine reached 390+

Like i statewd before though, it wsa running fine, and i was bringing idle down a little at a time, making a few wide open runs, coming back and turning it down more, then it stopped shifting and was hard to start, but i don't think it was getting hot then

 

[MotoGod]

Yeah too rich and you will just keep flooding it out and if it does fire it will sputter and run like crap. 390 degrees will start warping pieces inside and after that point the pinch of the engine will pretty much be gone and it will never fire up. These little motors have no rings, so they rely on the pinch (Taper) of the cylinder to make compression.

Most rigs have an adjustable shift point as well, so if it's not shifting, you can make some adjustments. I just had to do this on my Revo. At home in the grass and on the street it would shift just fine, but at the track it was stuck in 1st gear on the straightaway going VERY slow. I adjusted it to shift earlier and I was good to go on both now.

 

[jnjritz]

What brand temp gunn is it? I have a friend that told me he had to "tune" his temp gunn. He was having the same heat issues as you. Let me know.And i will find out what gunn it was. If its the same i will find out instructions for you also.

 

[benningtonr]

Ok, hey, the revo and tmaxx 3.3r are simular, did your breack in period go as planned. I have been putting it off, wanted to play with a used truck first, now that i have ruined that motor, kind of worried about new 3.3 tmaxx

it is the Dymamite pen temp gun I got at debies RC world

 

[MotoGod]

Break in is pretty simple. Just heat cycle it through like 6 tanks give or take. Little to no throttle when you first get going. There are some nice guides out here on breaking in an engine. Also before you start, find BDC and mark the flywheel and crankcase on the bottom. When you shut off the truck, move the piston to BDC again and let it cool.

Do a search on break ins out here. TONS of info. Have a hair dryer or heat gun handy as well so pre-heat the motor to make it easier to start.

 

[jnjritz]

Ok, hey, the revo and tmaxx 3.3r are simular, did your breack in period go as planned. I have been putting it off, wanted to play with a used truck first, now that i have ruined that motor, kind of worried about new 3.3 tmaxx

it is the Dymamite pen temp gun I got at debies RC world

Ok i'll check on the temp gun for you.
As for the break in there are 2 methods to break in that will give you good results. The traxxas method and the heat cycle method.

https://www.rcnitrotalk.com/forum/showthread.php?t=60832

At the bottom of the page Rolex explains the heat cycle .
Just make sure you put you engine at BDC "Bottom Dead Center" with whatever method you use. It will make the engine last alot longer . Before you start it up .Put it BDC and make a mark on the flywheel. With a sharpie or something of that nature. And after every run during break in and after break in, after bashing, or racing when you are done running your rigg make sure you put it at BDC.

Break in is pretty simple. Just heat cycle it through like 6 tanks give or take. Little to no throttle when you first get going. There are some nice guides out here on breaking in an engine. Also before you start, find BDC and mark the flywheel and crankcase on the bottom. When you shut off the truck, move the piston to BDC again and let it cool.

Do a search on break ins out here. TONS of info. Have a hair dryer or heat gun handy as well so pre-heat the motor to make it easier to start.

Damn i took to long to write it . you beat me MOTO.

 

[MotoGod]

i r fast!

 

[benningtonr]

Ok, thanks, I appreciate all the help

 

[Suicide]

what fuel are you running. blue thunder once it heats up no amount of richening fixes it. you practically have to kill it, restart and retune

 

[RC Addict]

Lovely, thanks
But why wouldn't it come down, we richened it to the point that it would die when I stopped the truck, and wouldn't start.
Also we are driving the truck on a large open grassy area

The reason the idle would not come down despite richening it would be one of two:
1) There is a severe air leak somewhere in the system leaning your mixture out, or 2) There is a severe air leak.

My point is that an air leak will lean you out. In your case, according to your temp readings, the lean condition was so severe that your temps were 390. If that is the case I have to agree that your mill is toast. The head is most likely warped and leaked even MORE air, leaning you out so bad that even a full rich condition wouldn't help.

I too come from a 1:1 background, and as funny as this sounds, SO WHAT. It means zero in terms of mechanics. We are talking apples and oranges here, not little apples vs. big apples.

I hope I am wrong, but from what I read I am willing to bet I am not...

Get a new mill and follow the "New School" break-in method.

P.S. I actually recommend Blue Thunder for breaking in a rig, especially a big block. It has so much oil in it that it keeps you from ruining a mill if you are a little too lean. But that is just my 1/2 cents worth...

 

[Suicide]

yes blue thunder is excellent break in fuel, because of how your running when you break a motor in. But for daily driving, once the oil gets hot enough it burns. then no amount of richening will fix it. (read the label it even says the oil is supposed to burn.) so a little lean won't kill you on it. but if in your case after its broken in. once that oil burns it doesn't protect your motor at all.

 

[RC Addict]

No doubt, Suicide. As soon as my sixth tank was done (two quarts of Blue Thunder later) I switched to Sidewinder 20% with 12% oil. Runs like a top!

 

[Suicide]

I did the same with my 3.3's broke in on 5 tanks blue thunder. then 10 more tanks of Babying it on Byron gen2.

 

[RC Addict]

Danm good fuel! My LHS does not stock Byrons and I refuse to pay ORMD shipping on a case of fuel so Sidewinder is my second choice.