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new tmaxx owner

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H

hulklil87gt

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hello everyone i just bought a brand new but used tmaxx. The guy said he bought the truck for his son and he didnt want it, so the truck sat for about a year or so he was saying. He told me that the truck has never been run just only put a bit in the carb to see if it started. Now wen i try to get the truck to start and idle for brake in its a pain in the a$$. Just yesterday me and a buddy (long time tmaxx onwer) got it to idle for 1 tank of gas. On the 2nd tank we couldnt get the motor to run right. It had a very bad pinging sound and would bogg out wen you would pull the gas, also would cut out wen appling the brakes... The other thing is the trans in the truck it wont engage untill the truck is under full throttle, and some times it wont even engage. Wen the motor is actually hot the trans wont work and will get stiff to move. Had the trans apart for 6hrs studying it and looking a the diagram everything seem to be there and in perfect cond. can't figure this sh** out and makeing me up set for the money i just spent on this thing thanks for the help....
 
reset the needles on the carb to the factory position. If the motor hasn't been broken in, it will die much easier when getting aggressive with the throttle. (its also probably too rich)
Its sounds like you have multiple issues with the drivetrain.
Inspect the clutch on the motor and also the slipper pegs.
how does it feel when you spin the spur by hand? truck move smoothly?

(what tmaxx is this anyway? .15, 2.5, 2.5R, 3.3)
 
Welcome to the site. First thing I would do is completely seal the engine. The seals can't be trusted after sitting a year. Read the tuning tips and tricks at the top of the nitro forum. It explains sealing in detail. Sounds like the slipper clutch is loose(nut in the center of big gear). That's why the truck won't move until it reaches high rpms. If the slipper has slipped excessively, it probably needs rebuilt. Inspect the clutch(on engine) when the engine is out. Wouldn't be a bad idea to replace it so you know what you have. If the old one looks just like the new one, save it for a spare. You WILL need it. Scuff the inside of the bell with fine-grit sand paper to remove any glazing. Use blue, removable locktite on any metal to metal connections when reassembling the truck.
 
I don't know if this is the case, but when my t-maxx made the pinging noise it was usually too rich, and the pinging noise was the fuel being slapped around inside the engine. I would agree sealing it would be a good idea, if that tranny is a 2-speed, you want to check the adjustments of those little fingers on the gears that pop out, it does sound like you slipper with the not engaging until high rpm's, but if those fingers are too stiff then they will engage at a higher rpm rather than a low rpm, mine having this problem always blows the gears because when the finger pops out it is like dumping the clutch in a car, all those fingers are adjustable, if you see the manual, you can find how to adjust the second speed for its shift point, there should be 3-4 gears in there that have the fingers that can be adjusted, so i would check that, more information would be good, like the kind of engine and tranny...:)
 
ok i would have to say more info needed ! how old is the fuel ? low octain fuel ( bad gass) will make the motor ping ! your ajustment needle any motor will start and run if you go all the way in then 2 1/2 turns out with both idle and air needles ! a dirty air filter or to much oil on it ! can change everything ! keep it clean and lighty oiled !
at this setting motor should be close on ajustments fine tune from there !
also remember your fuel can drop octain and can make ping ! so if you reset carb and still have ping get new fuel ! hope it helps
 
o my i forgot ! intell the motor runs right it will never shift right ! dont mess with more ajustments tell then ! as far as the clutch if you have the new 3.3 truck your clutch will not have fingers it will have disk pads that will not happen! and as far as the seals yes would not be a bad idea. but i would try what i said if it still happens get new fuel from there if it still happens or not get the seals it has sat for a year things will dry and crack ! so if it isnt the problem it will be sooner or later but this will give you the base of what the problem is or was and i wouldnt do it all at the same time so you can know what fixed the problem ! just helps if happens again to know! but like i said it would help with more info what modle of truck would also help to know what kind of clutch and trans you run lots of stuff is different on the 1.5 to 2.5 to 3.3 trucks most changes 3.3 truck but all 2 motors will start and run at that ajustment on the carb hope this helps.
 
Wildbill, with fingers i was talking of the ones inside the transmission, on a 2.5 model that is, could this be a problem for him with the "wont move untill high rpm's"? my 2.5 tranny, those fingers in the gears that are adjusted by a small screw/spring/ball were too stiff causing it to have a delay always causing it to strip the gears, i would check the slipper definitely, as well as the clutch.. :)
 
ok some more nofo about the truck, its the tmaxx 2.5 and trans was stock untill today. Converted over to forward only trans adjusted the finger on the slipper gear to really low for now till i get everything up running and tuned right. As for the motor i have been looking for some where to buy all new gasgets and no luck. I have reset the carb back to factory a few times and nothing still the same thing. I did how ever forget to mention wen i took my buddy we did put new fuel in it, it was 20% and got it to run on 1 tank perfect, now the motor was spitting out fuel like crazy from the ehaust and you could also see the motor was wet looks to be from the carb gasgets. Silly question maybe, can someone post pics of which are the right needles to adjust so i can make sure i am getting the rght ones thanks alot for all of the great info guys..
 
Nitro Tuning tips and Flow chart

That link is stickied at the top of the RC Nitro forum. That should give you some good info.

Don't bother with the transmission for now, as they usually won't shift correctly unless the engine is properly tuned.

If it's cold where you are, you'll be fighting the tune and you won't get a good break in.
 
If it is spitting fuel out of the exhaust, it may be too rich. Unburned fuel spitting out is definitely a sign, and if it is flooding that will cause problems with running and starting. If it floods it has to be drained or it most likely will not start, and sometimes after a good flood it may take a few times of draining it to really get it all out and restart. Don't take this the wrong way, but i would say you will probably keep having problems if you don't know the difference between the needles. Rolex gave a good suggestion, another manual is : http://traxxas.com/pdfs/4910_manual_2008.pdf : The engine running/starting depends on the fuel mixture, if the ratio of fuel and oxygen is off, it will not run right, or at least to its full potential, also depends on the fuel mixture on how long that engines going to last! I would check that out, and I'm sure you will have better luck!! :first_place:
 
He isn't going to get anywhere with fuel leaking out of the carb bore(make sure it isn't leaking from the front bearing and getting slung onto the bottom of the carb). Seal the carb, backplate and header with sensor safe, high temp copper rtv. A light coating on the o-rings does the trick. Use Team Associated Green Slime on the needle o-rings. It isn't a bad idea to seal the brass banjo fitting(hsn housing) while your at it. Carefully! The composite carb body strips easily. Check the fuel tank cap, fuel lines and exhaust coupler for leaks as well. Once your sure the engine and fuel system is sealed, it's time to try and start it.
 
Thanks alot for the info guys going to try sealing everything tonight. Can some one give me exact stock settings for the carb. It should be 2 1/2 out from close. On both needles correct? Thanks again will keep posted
 
4 turns out on the hsn. 2 turns out on the lsn. Start about an 1/8th turn shy of these since the engine is used. What's the outside temps where your at?
 
Maybe on an average of 25 out. But I have had the truck indoors with a temp of atleast 60.
 
25 degrees will play havoc with the tune, not to mention temps that cold are very hard on the engine's internals. The cold makes the metal contract, making the sleeve squeeze the piston more than it normally would. This causes premature compression loss(bad pinch). The bad pinch shows itself when the weather warms. Some folks have good luck wrapping the head with tin foil or a baby sock to keep heat in, but it's a crap shoot. If you do get it to run decent and drive it a lot in the cold, you can expect to rebuild/replace the engine when it warms up outside. A lot of folks keep an older, worn engine around just for winter use.
 
That's pretty much way this motors going to be used for (winter). As I have plans for a big block to go in :D.
 
I have to agree with the winter thing. I have a 2.5r i have ran all winter, it is about tanked....Going to get a new 3.3 this month, and will get the 3.3 going this summer, i had different opinions on the cold not too long ago, but i have now put the 2.5r through almost an entire winter, it is cooked....:)
 

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