JEBSR

I brought my revo and tmaxx over to Iraq with me to play in my down time. Once over here my revo was overheating (300+*). I did some research to find that it could be an air leak causing the overheating. I resealed the engine, all exept the carburator (I had done that previously) and reassembled it. Once I put it back together, it will start when I open the throttle up a lot but will not idle at all. I have reset the lsn and hsn back to factory specs and it still does the same thing. I ran it on the bench while adjusting the hsn and got it running great as long as I don't let it go all the way back to idle. I have adjusted everything every way that I know. I even have the idle screw all the way in. The carburator barrel is set properly as well. Also it seems to be running hot still. I ran it for about 1 minute or so on the bench and it went to around 315 again. Not sure why it is running so hot. It is plenty rich, not body on it, and not even at WOT. I'm lost, any help would be greatly appreciated.

pieky22

well im stumpted, u have your throttle trim on the controller up? and it does get frickin hot in iraq so maybe that is the problem...if i run my jato in outside temps of 90 degrees F or hotter... it doesnt perform right and i cant ever get it tuned right when it is hotter than that...what % of gas are u useing? and my revo is overheating alot also, i found out that there is an air leak in my front bearing. did u also seal that?...you probably shouldnt seal that, you should probably just get a new one... other than those possibilities i dont know... good luck!

RCCanuck

what fuel and plug are you running?

Mspeed

If your postive you got your needles rich as can be and its overheating on the lowend at idle, then its probably an airleak. I know you said you sealed your carb, and engine, but as pieky said that front bearing might be leaking or the bushing on the back plate or a head screw is loose. You can see the front bearing leaking, it will sling fuel all over the underside of the body and under the carb and some on the roll hoop. That will cause it to over heat very quickly and you will never get a good tune on the LSN.

HVNFNYT

It sure sounds like an air-leak. Have you checked your fuel lines and fuel cap O-ring?

JEBSR

Thanks for the input, here are the answers to the questions. I am running 20% fuel with a tower hobbies medium plug. Have also tried the traxxas factory plugs with the same results. It doesn't leak fuel around the front bearing or back plate at all. I sealed the head and retorqued the bolts to insure they are tight. Truck was running great, tune seemed good, idled for 30 seconds to a minute with no problems, just got really hot under WOT. Once it gets hot, it will kill the glow plug. There is no signs of damage on the glow plug, just looses continuity and will not restart. Once the engine was apart, there was also no signs of extreme heat or any damage at all. I have a new "o" ring on the tank and fairly new fuel lines. I already ordered fuel line, I'm just waiting for it to get here. I checked the back plate bolts as well and see nothing loose there either.

I did crack a couple of fins on the heatsink a while back, but it has ran fine and at the same temps as before after they broke. Could be an issue, but since it ran fine after, I kinda ignored that. I also think I know why it won't idle. Mainly because I believe I put something in wrong. I will fix that after work and try it again. Just can't get the heat issue to go away.

Also, my t-maxx runs warm, but not hot, in the same conditions that the revo engine runs hot it. Has to be an air leak or the heat sink I guess.

reiffron

i dont know how far you tore your motor apart but i had a problem with a no idle once and found that i put the piston in backwards. the cut out in the lower part of the piston goes towards the front. also watch the connecting rod, it has a little hole on the lower end that also goes towards the front.

pieky22

well my front bearing doesnt leak fuel or anything else either... what i did to find the leak is plug the carb intake and exhaust hole and blow into the end of the fuel tubing while brushing soapy water all over the engine with a tooth brush...

USMCREVO

Man, I didn't know you could get nitro fuel shipped to the sandbox. Gives me some ideas for the next time around. Anyways July in Iraq = 115 - 120 degree temps in the shade. That and the moon dust can make any engine overheat! Stay safe out there!

BANDGEEK1

The heat from the desert could be a factor.

systemlord

Take both your needles out and use compressed air and clean out those fuel passages.

JEBSR

Got the idle problem solved, resealed the engine again and it seems to run much cooler. It is running 260-280 and after shut down it jumps into the 320 330 range. I think that should be fine. The only issue is I have to run it pretty rich and the glow plug doesn't like it, but I can live with that if it will run cool.

I will still try the front bearing test, just to see.

Ran good though until the main jet housing, that holds the fuel inlet on, loosened up. Seems to be stripped. I can't tighten it at all. Guess I will be ordering a new carb housing.

It's a never ending battle.

Thanks for the help. I really appreciate it. Got to do something in my down time.