Revo Seriously Overheating

[ManicHaze]

First off, I want to say hey to everyone and thank you all for the helpful information that is held within this forum. I have been lurking for a few days, since I just got my Revo last weekend.

Anyway, my problem is my Revo overheats plain and simple. It overheats set to the factory settings for 4 out for the HSN and the LSN flush with the sides. I followed the break-in spot on, did everything they said in the DVD and everything. When i run it set to factory specs for the needles, it will get up past 300 with the body off. I live in Memphis, and its about 90 degrees outside right now. I broke it in with the Traxxas Top Fuel 20% and thats what I have been using since, and I've put probably 8-10 tanks through it. I have the Emissitivty set spot on on my temp gun, so thats not the problem...i'm just lost here :shrug:

I talked to my LHS and they said that I might want to try a motorsaver filter, or get brave and snag an ACNCM Giant head for the 2.5R.

I thought that maybe with the body off the flow wasn't concentrated enough, so i cut out half the windshield and the driver's side window to "Ram air" the air past the cooling fins, no luck.

To tune it so it runs in range (220-240) it has basically no power, and bogs like crazy, i tuned it and tuned it, changing just 1 thing at a time and no luck. I was thinking that this thing would have no problem yankin the front wheels off the ground if desired I messed with the slipper clutch too, and from what I can tell its set alright...how tight should it be? I can stick a allen wrench in that hole and turn the spur gear by hand it it slips with not too much force...is this too tight?

Now the hobby shop where i bought it thinking that something might be wrong with the motor and I should bring it in and they will check it out, if they can't fix it they will swap it.

Sorry to be long winded, I just wanted to give the full story. So heres the question I guess, have i been doing anything wrong? It makes me feel stupid that I have done everything I can think of to remedy this problem, read lots of posts on here and so forth....and still can't get it beat. :arrr:

any help or input on this would be very appreciated!

 

[Revo Rancher]

First of all, double check that slipper clutch. The manual says to screw the nut that holds the SC on to the trans all the way in, and back it out 1/4 turn.As to your temps, the manual gives you guidelines on how to adjust for weather changes. If it is hot plus humid, you may have to LEAN it out, not make it richer. This is all guesswork though, as we are not right there to observe what is really happeneing.

 

[beason]

sounds like maby an air leak.. if you just got it i would take it back.. make traxxas deal with it..

 

[ManicHaze]

yeah I think I will take it back, and let them swap out the engine since they offered to do that.

As for the slipper clutch, I was under the impression if i crank that nut til it stops I will bend the pressure plate? Is this not the case? or what did you mean about "all the way in"?

thanks for the assistance guys! I think i'm on my way to the hobbyshop to talk with them first hand and let them check it out. But keep the tips comming if you think there is something i was doing wrong, as i dont want to screw it up the second time.

 

[bashaholic]

I had the same problem x 2. Both of my Revos did the same thing as yours, could'nt run at factory settings (overheat) & would'nt shift unless they were running about 260-270. I did all the things people said to do, sealed the carb neck and the backplate, tried different fuel, even replaced the whole carb on one, nothing ever changed. I quit worrying about temps and just tuned for performance (good smoke trail & not cutting out at high speed) and had fun with them. It was always richer then factory settings &could keep it in the 260-270 range. I ran about three gallons through them before before I upgraded the engines. They still had good compression and were running good when I swapped them out. If they're willing to exchange engines, I would definitly try that.BTW the Motor saver will make you run a little leaner, it even says that with the paperwork that comes with it.

 

[ManicHaze]

bashaholic, its glad to know that a little more heat than reccomended wont kill the motors immediately.

Get this, my problem was the fuel! I took it up to the hobby shop and ran with my Top Fuel 20% and I showed them how it overheated, one of the pro racer dudes tuned it some and it still would overheat...I'm talking 300+ here.

The owner of the shop came out with a bottle of odonnel 20% and we tried a tank of that, we had to retune because you could tell that fuel made it act totally different. Once we had it tuned up, pretty much on the money and had a good smoke trail, the damn thing was running about 240-250 on hot asphalt in the hottest part of the day. The idle had calmed down too, it wouldnt surge like it did, with the top fuel it would idle horrible it would slowly speed up and then slow down repeatedly. Needless to say I was very pleased with the results.

They were saying that the oil content is too high in the Top Fuel, and it accutually makes it run hotter. I ride 2 stroke dirt bikes all the time, and I own 2 of them. I guess i was used to the way they act, more oil=cooler temps at a cost of less performance though. I knew the nitro/methane fuel would be different, and on this small of a scale even the most minute change will seriously effect the overall outcome. Just glad I got that all figured out.

Thanks for the help and suggestions, and be ready because now that this thing is running, I might have more questions when i start tearing stuff up lol :fro:

 

[ManicHaze]

one more question. ABout the clutch again, A guy at the hobby shop said dail it in pretty much all the way unless I plan on hitting a wall or something at WOT. Since i dont ever "plan" on hitting anything i dialed it in tighter than what I had it but still not till the nut stopped, I dont feel all that comfortable going that far in...but Id like some input from more experts before I go and get it too tight and screw up my tranny.

Also, when its tweaked spot on...should my Revo wheely on asphalt no problem? because i have yet to get it to pull more than 1 wheel off the ground trying to make it wheely.

 

[rbmaxxbasher]

is your fuel new? maybe the nitro content is weak.

I have two 2.5r's in my cars and they both run cold ~210. My S-Maxx pops wheelies and flips over on demand, and the Nitro Rustler acts the same. All I run is Top Fuel 20% and it runs great in all my cars. I haven't seen a heat problem at all out of it.

Let an expert look at it and pitch in their two cents worth. Who knows, you may be getting a new motor.

 

[J-Daddy]

What glow plug are you running in the 2.5r? I had problems with mine if I run a cold plug. Try the Traxxas 3232 plug or maybe a MC59 plug "both are hot plugs"...The hot plugs seem to run better in small block engines than medium or cold plugs.
Also if your in TN in July the humid weather is gonna screw with things some. I grew up in KY and I know how humid it gets there in the summer. Alot of engines dont like high humidty and it makes them a pain to tune. PLus the 2.5r is a touchy engine sometimes anyway. The LSN & HSN on the 2.5r are very touchy, it doesn't take much turning to change alot on them. Plus you have to look at what your checking your Temps with. We've found up to a 50 degrees difference between Temp Guns & Onboard Temp Gauges...I've ran the Traxxas Top Fuel 20% in both 2.5r engines & OS .18tm engines and I havent had any problems with it at all. My buddy is still running the 2.5r in his Jato and actually went from O'Donnel fuel to Traxxas fuel and his engine runs cooler & makes just as much power on the Traxxas Top Fuel, so I dont buy into the whole "Top Fuel is junk" thing.

 

[ManicHaze]

I'm running a mccoy plug, dont know which one off the top of my head though. The thing is very hard to tune here, but i've had alot more luck tuning it with the odonnel. It seems to run alot cooler with that stuff, and at my LHS its the same price as the top fuel so no problem there.