over heat !!!!!
 

ok i know this is a brushless website, but there's got to be a few nitros in here......

so this morning i went out to the beach with my son and granny.....
my t-maxx was running perfect.... between 190 f and 210 f.... when i got home, i cleaned most the sand and gunk off and ran it again.... running good around 200 until i busted the gas tank attempting a backflip......

ran to hobby shop, get new tank, remove and replace..... run it like 5 min. and its cuts out, smokin, check temp...... HOLY $H!T !!!!!! 318f

any suggestions?

Yes i've had a nitro but never ever runned on high temps.
this is a kind-of strange story.
was that gas tank the same amount in "cc's"?
was that replacment tank the same one as the one you broke?

because if its a lager gas tank then it must have ran longer then the motor was used to.

But!
if its the same stock replacment gas tank than that is going to be hard to find out whats the cause of 300degrese F
wow thats hot!

i have the revo with the 2.5R motor - 200 is too low of a temp - Did she shut off because of high temp - Did the idle race up and down before shutting down ? - i know that temps are ok when in the upper 200's - 300 is a bit high - i would say recheck all connections - make sure you didnt put a small hole in the fuel tubing - take apart stretch and plug one end and blow into the other - both lines from tank to pipe and tank to motor. Make sure your carb is not loose - make sure that you have no exhaust leaks - that will make you run lean quick. Do a once over on her - and retune it for about 260 or 280 - try that and keep an eye on it - I also had a problem with my RB .21 motor - the rubber gasket on the high side needle valve went bad - kept screwing in - hotter hotter - till we figured it out - check and make sure this is not a problem.. Youll figure her out....

ok, i went over the fuel tubes, checked the exhaust for clogs, checked every motor bolt for tightness/leaks, changed glowplugs to a new one, checked carb for previous setting i made on it, yada yada yada.......

the fuel tank is the same type (stock t-maxx)

started it up and within 2 quick high speed passes it bogged WAY DOWN, idle slowed WAY DOWN, then cut off, i immediately checked temp....... 345f......

all this within less then 2 minutes of start up.....


im about this close to calling it quits with NITRO already !!!!!!

sounds as-though you might have gotten sand in the motor and ruined the sleeve and piston. i had a similar problem when my airfilter came off on my revo. it wasnt as sudden but it didnt take long for it to come about as a major problem. it would be kinda hard to start, then i would get it running, make a pass or two and then bring it in for adjustments and as soon as i let off the throttle it would die. pull the head off and and see what you can find. also, roll the flywheel with your finger. if you dont feel any kinda pinch then you dont have any compression and its time for a rebuild.

well, its still got the "pinch" and i can hear the slight pop through the eshaust from the compression......

i guess ill just have to do a full tear down and see what i can find out.....

mom's in town so im taking a break for a couple days though.... and i should get my new FLM part in tomarrow for my rusty/stampede project also, gonna try something new with that and if it dont work, then i just wasted the money on the stampede chassis and braces....

Check for holes in the fuel tubing.

thats the first thing i did.... im just going to have to tear apart the motor and carb and to a full inspection, but ill start that tomarrow after work...

are you getting any vetaltion in the body?
or did you run the truck without a body?

i did recently switch back to the stock body..... i was running the HEMI body with windows cut out, i didn't even think of that....

guess i should try cutting the windows out of the truck body or fix my HEMI body so it will work again...

lol try that! and also take appart your engin and see whats the problem

It sounds like an air leak to me, but I wouldn't rule out sand in the motor either.

I think we can all agree that this is an air leak of some kind. It seems that you would have to run with the filter off to get sand in the motor but that is a possibility. It sounds like your on the right track checking the engine for sand and checking for air leaks. Don't give up on Nitro, just have a brushless system for backup like me when I get fustrated with Nitro. Good Luck.

been VERY busy with work lately, too tired to work on RC when im getting home this week, so i haven't torn into the engine yet, but i did find out one thing............:013: broken motor mount !!!

Is it possible for an engine to get hot if the clutch berring goes out? That might be something to check in to.

after it shuts off, will it restart immediately?

thats always the 1st thing i check.....

from my motocross experience, you are correct, messed up filter can cause many odd ball problems

oops...i edited as you were typing lol. anywho, did you see if it will restart it imediately? i had similar problems right after my revos airfilter come off and got dirt into the motor. it would run fine and then about 4 passes down the street later and it would shut off because it lost compression and the motor would warm up and then loose compression and die then it wouldnt restart till it cooled off.

that is EXACTLY what was happening......

well i tore the motor apart as far as i possibly could tonight, didn't know such a small carb had so many pieces, and cleaned everything with Q-tips and after-run oil. i couldn't fully take it apart because i dont have a clutch tool, couldn't even get the spring off, so i just hope i got it cleaned up good enough, guess ill find out tomarrow..... oh, also blew air through the carb to clean out clogged jet holes, yeah, some sand did come out......

well DANG...... woke up around NOON thiry, got drunk at bar last night.....
and now its about to start thunderstorming so dont get to check out the MAXX today..... :mad:1

chances are you need to get a piston and sleeve. what i would recommend doing is just trading up the 2.5 for a 3.3. its only 130 i think with the old motor and it doesnt matter if its running or whatnot. just look it up on traxxas' site. its the engine replacement plan or something like that.

HMM... i might look into that

when i checked the piston and sleeve last night, it appeared to be fine, no scoring or pitting or anything from the appearance of sand or whatever, even the piston head looked really clean for a well used 2-stroke.... im used to piston heads being black (motocross, 105 octane fuel), and this 2.5 piston head was a golden brown.....

like i said, i test it out again once it stops raining, hopefully it works right again, if not, ill look into that 3.3 or parting it out on ebay

Actually, it's OK for the piston head to be a golden color. That's the oil part of the fuel "carmelizing" (for lack of a better term). If it's too clean, there is a chance that there isn't enough oil (running too lean). However, if the golden brown is more black, you are running too rich and the buildup could cause premature wear as well.

have you checked the compression? roll over the flywheel with the head on and a plug in it. see if it has pinch or it it doesnt really have any compression.

oh, its got the compression...... actually i think you mentioned that before, or was it someone else.... anyways, i does have compression, the flywheel has the "pinch" your talking about, and i can hear the suction and pop of the compression when it releases once the piston goes past the edge of the ports in the sleeve...

Did the sand come out of the carb or motor? If it came out the carb that would explain the problems. It was cutting the fuel supply off at hi rpm.

the sand came out of the carb, i think it may have been clogging one of the jets, the motor seemed clean, when i q-tipped it, only came up with carbon build up

then you are VERY lucky it there wasnt anything in the motor. chances are it could have very well been the carb.

Have to let us know after the rain stops falling.

hopefully tomarrow after i take the little tike to church

well, i got out to the park again today..........

t-maxx did NOT over heat!!!! hell i could barely get it to run in the normal heat range of 250-270f (says TRAXXAS), running really rich, i finally got it pretty close, but then.....................SNAP!!!!

I guess 1hole piston + 7lbs springs + 60wt. oil + stock plastic bulkheads = bad idea for jumping.....


http://i14.photobucket.com/albums/a3...L/DVC00299.jpg

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the good news, i found a decent spot for jumping, and its already there so i aint got to build one, this jump (towards parking lot), im sure will launch my maxx over my SUV, once i get the carb tuned right, running like crap today i was still jumping about mid window level...... then going towards the grass 1-1/2ft. lip jump, 3ft table top, about 4-5ft sloped drop off, makes for good jumping over kids and scaring the hell out of 'em, LOL!!! Not enough rotation for backflips, i blame that on not haveing the carb tuned correctly yet....

anyways, this park seems like its got some good potention for RC'ing around, haha, my secret, the other locals go to another park thats all flat, soft grass, BORING!!!! or they just dont know about this park???

http://i14.photobucket.com/albums/a3...L/DVC00303.jpg

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the woods and rest of park (away from kids area), below nice berm jump at edge of parking lot
http://i14.photobucket.com/albums/a3...L/DVC00306.jpg


little jump and little more grassy area and wood on other side of parking lot....
http://i14.photobucket.com/albums/a3...L/DVC00305.jpg

what are you gonna replace those bulkheads with? aluminum is the way to go. for the price, the flm bulkless combo cant be beat really. its cheaper or just as cheap as bulks and cases plus its stronger, lighter, and just plain looks better.

i dunno, i like the FLM's, but the GAP's (great assembly products) have that access hole for the lower shock tower screw, although i guess i could just drill it out myself on the FLM's......

now its a toss up though, fix the maxx again, or finish the stampede......:007:

Like squee said, bulkless are the way to go, but if you want you can just use normal flm bulkheads, i had these on my old emaxx and they were great! Looks like a nice spot to bash at:)

actually, serum said that the ga's are made by flm. but yes, bulkless is definately the way to go.

I would go with some flm bulks. You don't have to go bulkless but is stronger in my opinion. The bulks are not to expensive either.

furryninjs, whatever floats your boat but the flm bulkless is your best investment in bulks.

when ya'll say bulkless you mean the hybrids right?

cause thats what im planning on getting... just need to decide on the standard gearing or the 1/18 scale gearing

The option that Traxxas has for turning in your old engines for a new one is available at most dealers if not all dealers of traxxas. For a new 3.3 it cost $135.00 with your old motor, but the price at most retail stores is $165.00 without turning in your old motor. I think any motor will bring more than $30 on ebay. Just some info for you to consider if the engine looses compression when warmed up. Good luck.