Crazy Engine!
 

Ok I was trying to break in my MGT today. It is -8 degrees C outside so that like 24 F I think. I set the needels for breakin according to the manual and heated the engine head up with a heat gun untill it was pretty hot. It started very easily after I truned the idel speed up a bit and I started moving forward. The truck ran well up and down the street nice and slow then it started to speed up and slow down and then speed up alot with no imput from me so I ran out and grabbed it as it drove by me and i got it just bfore it went nuts and was like WOT. The servos and stuff are not gitchy and it definatly was not overheated because it was only warm to the touch but it was surging just like when u overheat a nitro. I think perhaps this is a result of the engine being too cold because it was cooler than it was when i heated it with the gun. But i am pretty sure it is some sort of tuning or temp issue and not an electronic issue. Any imput would be appreciated.

RE: Crazy Engine!
 

I had the same problem with my Mgt...my problem was with the radio glitching,I changed the servos and it still glitched...I can see the servos twitching. I replaced the motor with a XTM 457 and been problem free ever since...some how the stock engine was causing interference. your problem could be a possilble air leak. You said it is -8 degrees outside..so the engine might not overheat because its so cold out. Check the minor stuff first. Check the fuel and pressure line for holes or tears and then the o-ring on the tank lid for a tight seal. What radio are you using?

RE: Crazy Engine!
 

I think u misunderstand the serveity of these surges, there is no way the radio is glitching that bad if it was then the thing would be useless. I think It may be running too lean because of the cold dense air here. Since I lubed up the engine before I started I think thats why it ran good for like 10 seconds and then went crazy caues of not enough oil due to lean mixture. I guess if there was a carb air leak it would run lean too. I will start it up tomorrow much richer and see what happens if it dont work I will bet its an airleak.

RE: Crazy Engine!
 

Yeah, the colder the temps, the richer you run to make up for the denser air. Try and put aluminum foil around the cooling head to keep some heat in and richen that sucker!:)

Cold - Rich
More air in the engine -> needs more fuel too

Warm temps - Lean
Less air going to the engine -> less fuel as well

RE: Crazy Engine!
 

O man soil was right that radio is glitching really bad! I turned it on without the engine running, put down the radio and watched my carb go all the way to half throttle and stay there on its own for like 10 seconds and then open and close some more! how can anyone drive this truck! is there some way to fix that?

RE: Crazy Engine!
 

Check for any metal to metal contact. If there is some, then try and put some plastic or something between the two metals points. Use a zipties or some elctrical tape. If it's the engine, you stumped me[:o]

RE: Crazy Engine!
 

metal on metal contact? [&:] where too? theres lots of places on the truck like that

RE: Crazy Engine!
 

Yeah, but if a metal piece moves, check to see if it touches another metal piece. Just wiggle some metal pices around the truck, shouldn't take to long.

RE: Crazy Engine!
 

ok ill check

RE: Crazy Engine!
 

I dont see any loose metal on there [:o]

RE: Crazy Engine!
 

I figured it out! The futaba sterring servo I put in is causing the glitches for some reason. I hooked up the stock one and it worked perfect. I guess I will have to put it back in tomorrow. At least I wasent running my engine too lean :D I thought It sounded fine when it ran. Thanks for the help guys u rock ;)

RE: Crazy Engine!
 

mine was the same way i sent it back to ae for a check and then when i got it back (3 weeks later) it did the same thing. the best thing i did was rip all the electronics out and installed a new one. the old reciever transmitter and servos went to heaven, as they say use a bigger hammer:D.

RE: Crazy Engine!
 

my radio equiptment has been goin awesome for the last 4 gallons, never glitched once. It does get a little slower to react when it gets further away but thats just basic AM radio working its way lol

RE: Crazy Engine!
 

Ya my buddy had a rc10gt with a similar radio and it was pretty glitchy. This one seems ok now that I fixed it. I was sitting there thinking "how could they sell a truck like this? I cant even control the throttle!" :p Then I remembered the servo I installed. Its too bad that servo dident workout it had alot more power then the stocker.

RE: Crazy Engine!
 

ye, did u put the servo in the right spot? U didnt put it in the 4th channel did you? I dont know if that would do anything but its somthin to think about. Maybe the servo was takin to much power away from the throttle and making it glitchy, if u had a 6v hump in there it might help a little, but im not sure:D