nitro rc

Hi,
I never really noticed until today but after running my tmaxx 2.5 for about 10 minutes and i shut it off to refuel, or it stalls, it doesn't start up right away, I have to let it cool for a few minutes. Then to start it i have to get on the gas immediatley or it stalls. is the not starting right away normal? or should it start right back up? Any input would help.
Thanks

racemaxx24

Usually when they won't start warm it means its down on compression and needs a rebuild. Thats what traxxas says[8D]

nitro rc

so what does it take to rebuild an engine? iam very new to this and won't do many modding. I just wanted a fast rc car. Does it cost much and is it really necessary?

slurp91193

i wouldnt rebould ur engone if i was u ............ i wuld go to ur lhs and swap ur 2.5 for a 3.3...........i did it and am relly happy with the power from the 3.3 compared to the 2.5

racemaxx24

Thats how I got my 3.3. Swaped a pro .15 and got a 3.3

NitroBobby

thread hijack....
word. i did the same thing. i pick up my 3.3 this week. what gearing are you using? i'm thinking of going with the 54tooth spur and leaving my 20 tooth clutch bell.

OP
how old is the engine?
what temperature are you seeing on the head?
it might be getting too hot and losing compression.
if it's got a few gallons through it and it's been run hot a lot, then it might be getting worn out.
an engine rebuild involves replacing the piston and sleeve inside the engine. usually this is in the $50-80 price range.
you can get a new 2.5r or even a 3.3 for not much more money and it'll be brand new.
is it normal? i think so. mine does the same thing when it's hot.
if it starts after it cools, then i think we've found the answer. loss of compression.
solution: don't shut it off to refuel (you don't need to any way). run it a little richer to prolong the rest of your engine life and keep the temps cooler.

matts6887

Well looks like u beat me to the punch here on this one overdrive he is right though usually a telltale sign that a piston/sleeve/conrod are on their way out is when it is hard to start while warm or it constantly dies when the engine is already warmed up....

nitro rc

ya i will start to refuel while running from now on. I thought the fuel tank opening would effect the engine but i realize that the racers refuel while running. So the engine has bout 2 gallons but i think it is normal to not start back u pright away because the compression is off for starting. My friends MT2 does the same thing. very hard to start hot. Thanks for the input.

matts6887

No problem.....glad to be of assistance(well as much as I can anyway)....any more problems just post away[8D]

iamnot

a poor tune will do the same thing

in my experience
if the pinch - or lack of
is the problem
it's not long before
it just starts to die
once it's warmed up

if your's has been doing this for a while
it's probably tuning

if it's just started doing it
reset to factory settings and retune anyway
it's free and may fix the issue...

rcnitrohead

My TRX 2.5 did that throughout its whole lifetime, it was always a pain in the @$$ to start when hot, but I ran it to the grave.. Forget trading in for a 3.3, just get a good .18 and you will be really happy[8D]

Stellar1

how much is a .18 OS engine and which one? the one on tower say its discontinued (.18TM Direct bolt on) My Maxx is doing the same thing and my LHS told me that i have no compression. he said he would get me the 3.3 for 165 but alot of the guys here say its hard to tune. is the OS easier to tune is it faster, torquier, stronger? thanks for the help in advanced guys.

racemaxx24

I went to hobbytown and did the traxxas ERP and went from a pro.15 to a 3.3 for 110.00 and I got the engine the same day. And yes the .18tm has been discontinued. Now the .21tm is the drop-in for the .18

Stellar1

nice, thanks for the update, do you know if its alot stronger?

nitro rc

what i also noticed today and yesterday is that my maxx is taking like 10 mintes to actually start (i mean the very first startup) The ez start battery is newly charged but it doesn't want to ignite. i replaced the glowplug but didn't help. i do get it to start but it takes forever. When it finally does a lot of gas comes out the exhaust pipe but then the exhaust is normall after like a minute.

matts6887

That sounds to me like u are wayy tooo rich on either the high speed needle or the low speed needle, or possibly both. Try leaning out(turning clockwise) the needle(s) 1/4 to 1/8 turn at a time...

nitro rc

ok thanks i will lean it out and start it up today. Ya even my dad said it was rich yesterday. I was surprised he recognized that since he doesn't know anything about my tmaxx. But i guess tuning is in 1:1 cars too.
Thanks

charlieboy

I totally agree, i don't think you need a new piston and sleeve or a new engine unless you really want to buy one.
Its likely your low speed needle setting is too lean, so it won't start when hot. Reset both needles to factory settings.

nitro rc

i know its not the LSN because i have never adjusted it. Way too hard to get to on a tmaxx. I wasn't going to rebuild or buy a new engine. I was only wondering if it was a small adjustment needed to fix the problem. Now I have to open up the tranny cuz something broke in it.

DaveG55

If the lsn has never been adjusted then that IS the problem. To tune a nitro engine it is every bit as important to tune the lsn as the hsn. If you've never tuned the lsn then your engine is nowhere near tuned correctly.
Besides, tuning can and does change from day to day, even morning to evening. Nitro tuning is not a "set-and-forget" kind of thing. That's one of the things that make people either love or hate nitro.
Take everyones advice, set all your carb needles to factory and then retune your motor. I think you'll be surprised by how much pore responsive and powerful your truck will be.

nitro rc

ok i won't be able to fix that problem since my tranny broke yesterday so i have to open it up and see what happened. i think it is the same thing that alreaddy happened, a broken pin

nitro rc

haven't been on the computer much since the tranny broke. But I ended up fixing it the next morning and bashing the last o my fuel. I still haven't had a chance to get to my LHS to buy more. Also, how much fuel do u guys buy at a time?

matts6887

It usually depends on how much bashing and/or general driving around Im gonna end up doing. For me I usually just buy 1 gallon at a time.

nitro rc

same thats what i have been doing. It lasts a good amount of time too, well at least for me since i can only run it on weekends cause school and sports

hollylx88

all the engines i've run when they're hot, they are a pain to start. i usually have to give it some throttle to get them to fire. but if your lsn is factory set you definately need to play with it. since you said alot of fuel came out i would say it needs to be leaned out. also it seems the newer the engine is, the more you go through glow plugs.