roppeltman

I really want to like this truck but my Losi Aftershock is driving me in the oposite direction....I put the HT pipe on it today and still get the same thing...It fires right up with half a pull,runs for 5 to 8 seconds ,shuts off and WILL NOT restart....I tried to lean out ,there was a ton of fuel coming out of the exhaust. I tried to go rich,same thing. I went to factory settings ,,,,,nothing.......Please ,if anyone has an idea,let me know asap ,cause im losing patience with this truck...It has the m26ss motor. I was thinking maybe a fuel pressure problem,maybe an air leak in the fuel tank???Im open to suggestions. I have been in the hobby for a long time and never had this problem before.

Foxy

Take it to an experienced tuner and ask for help in person.

Trying to help people with tuning problems via the internet is like trying to teach a dog to speak. Pointless, and irritating for you and the dog.

Lastly, the truck is not at fault for a difficult engine or a bad tune, and changing the exhaust was not likely to help with a running problem. Some RTR nitro engines are just born to make your life difficult, you can only get help from those who know better or deal with it.

HerrSavage

Have you tried a new plug?

There could be something wrong with your tank or fuel lines. I've never experienced it, but some people over the years have had issues with the tank leaking around the pump thing..

How old is your engine?

Another possible culprit could be your clutch.. I have had issues that sound like yours, where it would start, but only run for a few seconds, then die.. Turns out I had some toasted clutch-bell bearings stuffing things up..

I would say, if you haven't already, first try a new plug. If you still have issues, and are sure your fuel line and tank are OK, pull the engine out and check your clutch...

How much fuel have you run through the engine since you last changed clutch bell bearings?

cummins driver

My Feedback: (31)

How long have you owned the truck? Did the engine run correctly before?

I had an engine that had lost all its pinch. It would fire right up and run good for about 8-10 seconds and die and not start back until it had cooled off again. It was wild because you could start it, throw it on the ground and nail it and it would take off hard, then about 5 seconds later it just quickly came down from high rpm's and would die right in its tracks. Sounds similar to your problem, but its hard to say for certain.

roppeltman

The motor still has great pinch. I cant even get it off the back of my truck to try and take off. By the time I get the ignitor off ,set the drill down ,and grab the remote ,,,,its stalls.....I bought this truck used .When I say used ,its only because I didn't take it out of the box. It is brand new and has only been run a few times,by the looks of the body ,frame, etc etc etc...I'm wondering if it is even broke in ,and if it was ,was it done correctly ?  I' ve been in the hobby for a while now and I know how to tune a motor, so I refuse to take it to someone and pay for them to do the same thing i'm gonna do....I'm going to go with a cold plug and see what happens. I read in some other posts that people were running a cold plug, so ill try it and see what happens. I have my eye on the Losi 454 . Thus far from what I have read its sounds like a decent motor for the money. The reason i'm looking toward a new motor is because of the fact that I don't know anything about the current motor on the truck such as break procedure...If I buy a new motor I will know exactly what I have and know that it was broken in the way I wanted it to be broken in.I really appreciate all the help guys, and I do listen to what all of you have to say. I use this forum a lot and I have turned a lot of people onto this site for information. Thanks for the help again and I will keep you posted on what the outcome is ....

Breakstuff

Too rich

roppeltman

I used the old hair dryer trick on the motor, leaned it out to 3 turns out from bottom on the low speed, threw a new plug in her and bam......She ran like a champ. In the mist of trying to get this thing started and running, I never charged the battery pack....So after a few minutes of playing in my yard, there it was ,full throttle stuck against my fence...It took me some time to get to it ,but I think I saved it in time before and major damage was done to the clutch.I didn't rip it apart yet so i'm not sure. If there is any damage ,what would any of you suggest in the after market clutch world ? Metal,composite,3 shoe ,2 shoe??? thanks guys for all your input. Yes I put a new plug in , yes I leaned it out, yes I checked to be sure I had no air leaks, yes I held the wifes hair dryer to the base of the motor, and after all of that , it runs. It runs pretty dam good I might say...It takes off a lot harder than any t maxx ive ever owned...THANKS AGAIN GUYS !!!

HerrSavage

Good to hear... Now keep an eye on those receiver packs.. [:@]

Clutch-wise, the stock XXL LST2 aluminum clutch is great. And cheap on ebay*. No need for anything else.

Over time, a couple things to look out for would be 1.) the LST2/XXL HD pipe, 2.) an LST2/XXL 2-speed, which has a bearing in it instead of a brass bushing like the AS, and maybe for a bit more speed, 3.) XXL transmission output gears or a whole XXL tranny(easier and about 30 bucks..). The gearing is talleer for more speed.. You can also get an XXL clutch bell which has one tooth more on it, also for more speed..

If you want to get serious then there's also RPM arms, etc.. And if you end up jumping much you really ought to get a Dynamite engine brace..

Anyway, have fun...



* If you don't already know about it, jennysrcparts on ebay is a GREAT source of Losi MT parts.... There are others too...

roppeltman

I get most of my parts from Jennys or RCBoyz. I have the HT pipe on it already and the xxl tranny just shipped today. Im assuming its a direct replacement,so ill probably have it on for this weekend. We are going to be jumping a lot so I will buy the engine brace,never really thought about that before. Thx again for all the help.

devious1

My Feedback: (15)

Whats the temp in your city your trying to run in?

roppeltman

Its in the mid to upper 30's.....I just had it out in my yard .I have never seen this happen , ever...The truck started and idled fine .I put the body on and prepared to run a few laps in my yard. All of a sudden the motor starts screaming. I thought to myself, here we go ,the dam linkage was stuck again, after I spent an hour trying to figure out how to keep the stock linkage from binding up...... . Nope ,I look inside the carb and the slide is in the idle position. I physically push it closed the rest of the way ,thinking it would shut the truck off and it does nothing..Its still screaming......I pull the throttle all the way. Bam ,truck wheelies and takes off like a rocket. I pull the brake . It stops ,but is still screaming...It was about 30 degrees when I did this...Im done ...Im not running this truck again untill its at least 50, or higher. I was thinking its way to cold to be running these and this is the cause my crazy motor acting this way. If I had hair I would pull it out...I am a Traxxas man at heart and i've run my T- maxx anytime anywhere. Winter ,summer ,rain ,or snow ,my T -maxx fires up and runs. I run a 3.3 motor. Is the big block that much of a difference? Is a Losi set up that much different than a Traxxas...Im not talking quality,im talking basic ,down to the bone principals of how a motor works in the nitro world. Please ,im not looking to start a Losi,Traxxas war. Personally I dont give a rats ass who makes it. If I can start it and have fun while blasting the piss out of it ,,,,,,I like it !!!!!

roppeltman

Well no need to answer why the motor was screaming with the slide completely closed. After sitting down to collect my thoughts, I realized one thing. I have to have a vacuum leak somewhere. It would explain the hard starts, erratic idle and throttle response,it explains a lot. Looks like i'm going to rip her down tomorrow and look for this breach in air. I hope its something that stands out and not a hairline crack that is not visible with the naked eye.

Maj_Overdrive

My Feedback: (11)

If the fuel tank still has its primer that's the place to start, and by start I mean remove it and plug it! Mach motors are good motors, not the most powerful, but if you can tune a traxxas you can tune a mach, its probably easier as a matter of fact! Once you get the bugs worked out of course, try going back to stock settings if you're that far off. Gotta love nitro curve balls though. I had an OS 30 I was trying to break in, was rich enough at idle, and in midrange that it would almost stall but would overheat when I tried to get the rpms up. Turns out I actually had to lean out the high speed by almost 3 turns and richen the low end by almost 2 from the factory settings just to break the thing in.

BTW, in cold weather you want to use a hotter glow plug than you'd normally run. If you go up a heat range or 2 in your glow plug you may not have to tune it too much and it will definitely make your life easier. Take it from a member of the frozen fingers club!

1QwkSport2.5r

You dont change to a hotter glow plug when its cold out. You run the same glow plug in summer as you would in winter with the same fuel. If your engine doesnt run well when its cold outside, you're tuning it wrong. Cold air is denser and holds more oxygen than hot air so your mixture needs to be richer. Keep in mind also, you want your engine at operating temp before making adjustments unless it will not run at all. Glow engines run very rich when cold, as they warm up the mixture evens out. Get it hot, then adjust it. If you listen to the noise the engine is making, it will tell you how its running and you can make the necessary adjustments. Also, The idle mixture controls fuel mixture from idle to about 3/4 throttle. For break-in, most of the time you should not need to mess with the high speed mixture much at all. If the engine wont idle at factory settings, its too rich.

On a well broken-in engine, factory settings are oftentimes too rich to have the engine idle. Whatever the factory settings are, I go at least 1/2 turn leaner than that. Its always worked for me; winter or summer.

devious1

My Feedback: (15)

One of the things i have always done with the cold air and sub zero temps is i would wrap the head with tinfoil to help keep the temps a little more normal...
i would seal the motor and needles along with throw all new fuel lines on to eliminate all possibility's there.