chrisstockton

Hello, my name is Chris. I just recently purchased a revo 3.3 off of craigs list. It ran decently when I picked it up, but since I handed him the cash I have had nothing but problems. I really should have known better when I bought it cause it took me three trips to his house to get it running, I was just overly excited, and I am slightly compulsive.

So, it ran for a couple tanks of gas and stopped working, I bought new fuel, new glow plugs first. It seemed the glow plug wasn't sparking at all. My big mistake was when it would not start I tried to tune it, following the manual the best I could, I ruined it to the point it would not start with a glowing glow plug (i put it against the frame and it glowed). So, I took it to hobby town usa, to have a "Nitro Guy" tune it. It was 20 dollars a hour, he said pay him 40 and he would have it running awesome. He called me 15 minutes after I left and said it was ready to go. I showed up and the broken antenna he tried to fix didn't allow him to even check how it ran, but it was "done". I made him put in a antenna and show me in the parking lot. It ran good in the parking lot, kind of like how it did when I bought it. My experience there is a story separate from this though.

SO, excited as hell to ride my new car, I took it to the park, and guess what, would not start, all it would do is grind. So, I took it to the hobby shop, and after some BS I got the little bearing for the ez start so it would stop slipping. He made me go change it in the parking lot. Whatever, all good I need to learn how to do this stuff myself. So, I did figured it out, and got it starting pretty good now, doesn't slip and such. So, I took it to the park and it started off running pretty well. But after a few passes it started to lose it's acceleration, then it started to bog on high speed too, eventually as I gassed it, it would just barely start to go, till finally it just shut off. It was really hot, think maybe it over heated. The glow plug in it at this point, was fouled. So I changed it out, let it chill a minute, put it on the ground, filled it up, and it started back up, was running okay but after a while, the same identical thing happened.

Note, after the first problem instance, I started to try to richen it, thinking it was to lean and over heating, but check this, if I leaned the HIGH speed needle even 1/16th a turn, it would not start, if I leaned it back 1/16th it starts fine. So I guess its as rich as it's going to get? At this point I thought the low speed needle might be a issue, so I set it to 1.75 turns. The default from the traxxas website, I then started doing the high speed runs, the acceleration was boggy, and some times it just didn't get high enough to shift to second, but other runs it would run how it seemed it should, I just tried to richen/lean it till I got it to idle down when I pinched it like traxxas said.

After I had it idling down like they told me to, I got the high end as rich as I could without killing it, there is just that one sweet spot that allows it to run.

After a few runs, it eventually started the whole slowly dieing thing, till eventually it had no acceleration and died. It would not start back up when I put gas in it, since then I have not even F'd with it. I have spent now 250$ on the car from craigslist (thanks a lot KEVIN) and about 150$ on tuning, glow plugs, fixing broken stuff.

Are these cars always such a pain like this, I've always wanted to have a really nice nitro rc but just now in my life have the career that I can afford to run one. But I am not rich and don't want to keep throwing money at it. I REALLY want to learn more and have some good fun, like the guys on the you tube videos with revos, that just gas them up and run, great, over and over!!!

Is my problem unique or is this what I should expect?

How does someone get into this stuff gracefully? Should I have just gone electric ? I have a team associated 1/16th scale, and it just runs as I please never any problems, but its not so fast and the battery goes dead to fast. I really want this revo to run right.

Not sure what I'm asking, if anyone reads even 1/10th of this message and has advice I would be much obliged. I live in mesa arizona.

-Chris

revo-nation

Do you have a temp gun?
What temp are you running?
You must trouble-shoot your engine by testing to
see if you have any compression!
By trying to turn your flywheel with your fingers under your truck.
If it is spinning without any popping sound or any tension against
your finger then you have no compression.
Now It sounds like you ran great in the beginning of your
runs then it will sputter out in the end of your run,
that is meaning that you are running at the wrong temp,
you need a temp of around 200 degrees steady no less!
MAKE SURE YOU RUN AT THE SET TEMP OR YOU ARE JUST KILLING ENGINES!!!!
If thats not the case then you have air leaks gas leak or con rod or bearing problems.
In order to fix and diagnose problems you must face problems.
After taking apart your entire revo you will learn alot, at that point everything comes easy.
The first few problems are a real beatch, like tuning or dealing with carb or engine problems.
You will find out it is all worth it in the long run so just have patience with something you arent familiar with.
Hope this helps

beer=food

You got a bit unlucky mate, it does sound like the engine is on the verge of needing a new piston and sleeve, but most is covered above.
My hint is next time, especially if your new to the hobby is to buy new, you have only saved a few bucks at this stage and after a new piston or motor, a new one would have been better, very few second hand nitro cars have not been flogged, second hand ones are great for parts, and not engine parts, new ones are pretty awsome straight out of the box, l saw them for 529ish at towerhobbies, maybe try auctioning it back off and use it towards a new one, you will be amazed at the difference l suspect.

chrisstockton

Thank you very very much for the replies.

The compression is actually pretty difficult to turn with my finger.

I will buy a temp gun, I have a feeling your dead on with it running hot, my question is; how to run cooler? lol

-CHris

beer=food

If the motors tired, as it warms up its not holding a tune and may be leaning itself out as the bore n piston expand.
If its got great compression as l assume you believe it has, its likely a minor problem, like tune, maybe your bottom end fuel settings are pretty spot on, but your top end needle is lean.
Maybe you have an air leack around base of carby.
Check fuel lines for splits that are small and dont open up or suck in air until the revs get up from the backpressure.
Suss the type of fuel you use out, make sure its a reputable brand.
Do you run a hot glow plug you can buy ones that run cool warm or hot.
l live in queensland australia , its pretty humid and hot here, l run 20%, if it gets warm l richen it a touch, pretty rare but, holds a good tune , l use it in the heat of the day sometimes and sometimes first thing in morning, cut a hole in the windscreen to allow more airflow directly onto cyclinder head, if you dont have a temp gun yet, you can use the spit test, not the best but it will tell you if you engine is to hot, bit of spit on finger ,wipe it on top of cylinder head, if is sizzles away real fast its to hot shut it down let it cool and re start/tune.If the spit just slowly bubbles away with no real hissing, its not to hot, this is a rough guide only for people with no temp gun, it is how we used to do it years and years ago at the onroad nitro track events when temp guns were expencive and rare.
good luck.

madmax22

what fuel are you using?? (10%, 20%, or 30%)? and the brand of it? Traxxas is recommended for traxxas engines.

nitrorc89

i just had this same problem with hte 2.5 in my tmaxx...it turned out to be the little bearing behind the 'flywheel.....i wasnt airtight....it would heat up till no acceleration...and die...overheating and everything just like u described....use the bubble test and test for airleaks...almost certain that is what it is

and another thing...them guys on you tube ussually dont run just over and over....everytime you run you have an after run procedure...things to check....they are constantly tearing things down to clean and see how everything is going....

chrisstockton

I am using 33% traxxas fuel.

nitrorc89: That sounds like what my car does, cause eventually, I can hear the engine going strong still, but the car quits moving. I will have to look into more about that bearing.

I am also wandering if my clutch is too loose/tight. Nothing seems to be a exact science, seems like it just takes experience to get your car running nice.

Is there like a wikipedia for rc cars? Or good tutorials/reads? Maybe a book? I don't want to just give up I want to learn this stuff throw some money at it and have a really sweet car.

-Chris

nitrorc89

#1 place that helped me is actually forums....you can google stuff...arcticles on websites...buy some magazines...they help a lot...also another good thing to do...is tear your truck completely down and put it back together....that way you have a good idea on how everything goes together and works...run into any problems...just post on tthis forum..plenty of helpful people on this forum willing to help you out....

megamaxx

sounds like a tired engine to me,dont give up,just have some patience and tackle one problem at a time,i would either rebuild the old one or,if your just gonna dump money into it anyways,upgrade with a new/better engine...i have always disliked dealing with used engines,more than 1/2 the time you end up with a paperweight!!!!!

chrisstockton

I am considering just going to the local hobby store which participates in the traxxas engine replacement plan, and pay the 130$ for a new engine. Then I KNOW the engine is new and can trouble shoot the other stuff easier, I think.

Thanks a lot for the help, I am going to mess with it and see what I come up with, I feel much better knowing there is experts here willing to share wisdom.

-Chris

nitrorc89

lol the trx motor period i believe makes a good paper weight....saving to buy a new motor for my maxx right now....its still running but...just dont like it...

revo-nation

I wouldnt do the plan with trx because you can spend 50-100 more and get a monster motor that will be way more dependable and have more power!
like an os motor or a rb motor or a picco motor

nitrorc89

i agree with revo nation.... was in hobby town not to long ago...they had .18 tm still there for $145..they put out more power and imo a hole lot better motor....