hay and help me with tmaxx

[michael]

i have a t maxx i bought used it will only run half throtle has good power but wont idle and only start at half throtle

 

[nedlynitro]

Check your idle, idle gap should be between .7mm and 1.mm, another possibility, try leaning the fuel, just a guess at it, is it flooding when you do this?

how new is it, did you get it and just try to start it? My maxx used to do what you tried to explain when the engine had not been cleaned out enough before using it, for a while i used 3-in-1 as an after run oil, and found using that oil it took a lot longer of draining and cleaning before it would run properly due to it trying to burn the oil, so that is a possibility as well..

Here is t-maxx instruction manual, the t-maxx 2.5, I'm sure there is an issue with your fuel ratio, look into that manual for the engine settings and adjustments, be sure to read important tips, and post an update, we'll get that maxx going!

http://www.robotcombat.com/products/images/tra4910-manual.pdf

 

[michael]

i tried to lean and rich it did not help and changed fuil lines

 

[nedlynitro]

If you have tried the adjustments and have not gotten any result, i would then suggest cleaning the engine, and the carburetor, if you search rcnt forums, there are many on cleaning the carburetor, but at least a simple cleaning, to make sure there is no old oil from the last time it was put away, also, how does the inside look? for the piston, a good way to check an engine and see if it is warn, is to feel for the "pinch" that the piston will have reaching the top of the sleeve, most times if you remove the glow plug and turn over the engine slowly try to feel for it, because if the engine is warn it may be time for a rebuild! I would start with cleaning it.

 

[michael]

it was burning out glow plug and the guy at the hobbie shop said to rich it i did and it has not ran right since

 

[nedlynitro]

Also, after a good cleaning, where you are starting fresh, i would suggest adjusting the needles and idle gap to the factory settings, witch you can find in the manual.

 

[michael]

Also, after a good cleaning, where you are starting fresh, i would suggest adjusting the needles and idle gap to the factory settings, witch you can find in the manual.

i will try to clean the carb tomarrow thanks

 

[nedlynitro]

That sounds about right, how lean had you run it compared to factory settings?? This is important where if the engine is run too lean for even the shortest period of time it can ruin the engine, cause it to heat, and as we were discussing in another forum today, the engine becomes under lubricated, and will usually ruin it, but lets not jump to conclusion, as you read in the manual, and others as well, when making adjustments on a nitro engine, you usually will make turns in the needles at 1/16 of an inch, you may be skipping over your happy spot, too lean or too rich, this is also a possibility, look in the manual it will talk of signs that point to over lean mixtures and over rich mixtures, very important to know when running these machines, after a good cleaning, and adjustments have been reset to factory settings, i would then try to start it again, look for the sings i talked about, fuel coming out the exhaust could mean too rich, over heating and little to no blue smoke coming out the exhaust could mean too lean.

 

[michael]

i will clean the carb tomarrow and get a new glow plug and let you know

i did not even run3/4 tank

i did not even run3/4 tank

i did put after run oil on the piston

i ran3/4 tank and i did put after run oil on the piston

 

[RCPF]

Unless I miss read your posts, you didn't mention your LSN needle setting. I bought a used T-Maxx and it the first thing I did wrong was "assume" the previous owner had it tuned right! He wasn't even close and so now I always start at the factory settings and fine tune from there until I achieve "Optimum Performance"(in my mind, anyway)...Just a couple of thoughts and you can refer to the Traxxas site for tuning spec's...

Hope this may help Ya!

 

[michael]

i put my hsn and lsn to factory spec and it was running lean i just can't get it to idle now unless i give it half throttle like it is not getting enough air to rich butt my glow plug is not real good i am going to get a new one today and clean the carb is there anything else you can think of

 

[nedlynitro]

yeah I'm sure you did not hurt it michael, when cleaning the carb, be easy with it, some of the screws can easily be stripped out most screws on your maxx only need to be snug, i have seen many carbs ruined due to the two smaller screws being stripped, clean it, factory settings, try again, also, did you check it for that "pinch"? That is a good way to tell if it is a healthy engine, but like everyone else said, you do want to reset the settings to factory, and as you said about putting after run oil in it, when trying to run it, i would clean that oil out really good or that could cause it to act like that if it is trying to burn oil, you want to act as if it is flooded, to clean out that oil before a run, usually i would pull the glow plug, hold it upside down and turn over the engine, hold a rag over the engine to keep that oil or fuel from spraying everywhere, this is what you do when it is flooded, and most times, i would put the glow plug back in, turn it over a few times and pull the glow again to drain, sometimes doing that will help pull any oil out of the carb with the compression...

If there is oil in the engine when you try to run it, it will flood and act if it is too rich, so you do want to try to get that oil out, turning over the engine without the glow allows fuel when its flooded, and in other cases allows oil to come out without the engine pulling more in where it is lacking the compression when the glow is out, this is why i suggest pulling the glow and turning it over, then put glow back in, turn it over, and remove it again to drain, once your sure there is not a puddle of oil on top of the piston, it should be good to try and start, i have had these issues before using 3-in-1 as an after run, it would take multiple times of draining before it would run correctly, wd40 works best as an after run in my opinion, and traxxas even suggests it over some of there own after run oils, 3-in-1 some say works good, as well a marvel mystery, but i would suggest wd40, you can find youtube videos on the after run procedure, and what to do when it is flooded,

If your cleaning the engine, should probably clean the air filter while your there, cleaning the air filter is easy, soap and warm water, wash it good squeezing it and getting all particles out, then make sure it is completely dry before using it, and you will want to oil the filter, squeezing out all access oil, i use 3-in-1 on my filter, but some would not recommend it, there are oils you can get for that filter you may want to look into...

 

[w bill]

After trying everything that was suggested to you if your still having the same problem check the head for compression leaks put a little soapy water around it turn it over by hand see if you get bubbles. Also by the crankcase cover put a little shaving cream around that turn it over and see if it sucks any of it in sounds more like a carb problem to me but u need to eliminate all possibilities!good luck hope you geter goin

 

[broken_civic]

sounds to me like it is rich.

what is the hsn set at?

 

[michael]

thanks i will try it when i get home at 4 and let you know

 

[michael]

still need help

cleaned carb new glow plug set needle to factory spec still will not idle

 

[nedlynitro]

Messy huh? Hang in there we are only getting started for a next step, one option, would be of course to lean the fuel a little, i have two questions, is it flooding? and is the clutch working properly? If the clutch is dragging, it will not want to idle, you would know because when trying to start it the maxx would try to walk away, leaning the low speed needle (lsn) may be what you need if it is flooding out, did you do what wbill suggested? You should want to run some tests on the engine to be sure it is not blown before replacing all kinds of parts on it, wbill had a good suggestion, and as i said before checking for the pinch is another, the piston should have a little pinch when reaching the top of the sleeve, a feeling that it is very snug, try those things, we may want to be sure it does not need a rebuild before replacing gaskets and seals, witch would be my next step, in my opinion.

Also, when the servo is in an idle position, is the carburetors arm closed all the way? Be sure not to turn up the idle by trimming the servo, this can be bad, also something to check for, some times the drive shafts can be up against were the air filter hooks to the engine, causing the slide carb to be cracked open, we want to make sure it is closing all the way, and then make sure the idle gap is between .7mm and 1.mm.

Typo, not the drive shafts, but the throttle shafts, witch hook to the servo and carb.

 

[michael]

i did checkthe pinch felt tight did not do the soap and water or the shaving cream i have to choke and throttle to get it to crank and only get a little smoke i did check the clutch it spins free

 

[nedlynitro]

Well, once you have exhausted all the options of adjustments and checking the engines compression and condition, plus performing the cleaning, once your sure its not a matter of adjustments, i would move on to the gaskets and seals, they say even a pin hole in a gasket or seal can cause problems like what you are experiencing, when you cleaned the carb, did you make sure to clean all gaskets/seals and the surfaces they are sealing? If any gaskets or seals are dry, or cracked, it will cause problems, cleaning them, and were they should be, as well as lightly oiling the rubber seals to be sure they are not leaking, check and make sure some of them aren't visibly leaking, especially the gasket that goes between the engine head and engine block, the copper gasket is one you should not have to oil, but would suggest to clean, oil the rubber seals, also, try putting the glow in, and put some fuel or soap and water in there around the glow and turn it over, to be sure the gasket on the glow plug is not leaking.

If the copper gasket between the engine head and engine block is leaking, the engine will loose compression where the air and fuel will leak out, in most cases you will see the result in a leaky gasket in that location, for other seals in the carb if they are leaking, this will cause problems with how the fuel is passed through, and its ratio as it is being mixed with the oxygen, rendering all adjustments useless and inaccurate, another thing i am concerned about, is the fuel you are using, how old is it? usually fuel will keep for a long time, but it is always a possibility, i would be sure to check all gaskets and seals.

Once you have exhausted all the suggestions i have givin you, i will soon be out of options, where we have covered the majority of the engine, cleaning, adjustments, gaskets and seals, if no luck, after like i said, exhausting all options, i would then consider just ordering a new carb, and possibly piston/sleeve, witch you would then want to go ahead and replace the main bearings, it is important to check for any leaks, because so far i have my bet down that there is a leak somewhere, causing issues with the engines proper running cycle, i would suggest exhausting all these options before purchasing new parts to perform a rebuild!

 

[michael]

i will pull the moter tomorrow and do a gasket check there is no sign of leaks at the head i tuned it some more and got it a little better butt not a idle yet but it is smoking more thanks i will let you know