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Old 05-03-2003, 09:24 AM   #1
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Default engine question and radio question

First the radio question. I was out on my street running my car when all of a sudden the car goes bezerk. it wouldn't respond to any of my commands, went full speed off the street into the dirt. this is a brand new radio and reciever and servos. this is my second time running it and when i ran it the first time there was no problems. I am going to check over the receiver and wires to make sure nothing is squished or loose, but if everything checks out, what should i look for next? The only other thing i can think of is that my street may have radio inteference, but the same thing happened to my other radio and reciever. 2 different brands. One is a JR XRS3i running on FM and the other is an airtronics running off of AM. But both of them have now gone bezerk. Any ideas?

Second question. The engine. While the car was spazing out when it went into the dirt the thottle was at full speed (or very close to it) for about 6-8 seconds just spining the tires and not going anywhere. Since the engine was at high RPM do you think it may have damaged the engine? I have an MR12. After it did all this i waited a few minutes and tried it again. but the same thing happened. but this time while it was doing donuts in the middle of the road i was able to shut it down before it got into the dirt. When i started it up again it sounded fine, but i couldnt really tell since it only went for about 10 seconds before it spazed out again. I just want to make sure i didnt mess up the engine.

while i'm at it, here is another question. this one about fuel. right now i'm using backyard basher 20% nitro, 16% oil. My other engine uses maxys 20% blend. Could i switch the first engine from backyard basher to maxys since they are both the same nitro percentage? I like the maxys better.

Last edited by alucard13; 05-03-2003 at 09:29 AM.
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Old 05-03-2003, 09:38 AM   #2
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Yes you can change the fuel to a different brand. By doing this however the engine will need to be retuned.

Regarding your radio problem. As you said I would check all wires etc. Sometimes the crystal in your receiver can vibrate loose which would cause some problems. Check the prongs on the crystal as well...make sure both of them are still snug.

Check to make sure that you didn't have ANY screws come loose that are metal to metal contact. A loose metal screw on a metal surface will interfere with the control of the car. Metal on metal vibration is definately not a good thing...it's important to take a screw driver to all screws on the bottom of your chassis after each run if you can.

Since your radio is brand new I can't think of anything that might be wrong with it. You haven't dropped it or anything I'm assuming?
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Old 05-03-2003, 10:00 AM   #3
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nope, havent dropped it. i just finished the kit (read post Finally!) on thursday and ran it after work on thursday and it ran fine. this is my second running of it. Also, what do you think about the engine? Would 6-8 seconds of high rev have damaged it? I'm going to take the battery tray off right now and see if i squished the wires or antenna wire and re check my screws. thanx scorp....SEMPER FI!!!
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Old 05-03-2003, 10:10 AM   #4
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6-8 seconds is hard to say...generally speaking I wouldn't say yes but I really can't say because any prolonged high rev free wheeling can possibly hurt it. If you have any worries about it, inspect the piston and sleeve. If your sleeve isn't keyed, and you decide to take it out, make a mark with a felt tip marker to mark on the sleeve and the sidewall so you know it goes back in the proper direction and seats the way it needs to.
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Old 05-03-2003, 10:44 AM   #5
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i took the reciever out and made sure the crystal was pushed in and the radio as well. then i changed the batteries in the reciever just in case. I am going to test it in a few and see how it goes.
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Old 05-03-2003, 11:20 AM   #6
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ok, it ran great, no interference or the car going bezerk. The engine sounds the same as before and it seems to running like it did during the first run. If the engine was messed up, would i know it right away or not until a while later? BTW, the engine has already been broken in by the guy i bought it from.
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Old 05-03-2003, 11:24 AM   #7
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If the engine was messed up you'd be able to tell when you tested it.
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Old 05-03-2003, 01:18 PM   #8
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does anyone know what the highest temp would be on the mugen Mr-12? the guy i bought it from said 220.
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Old 05-03-2003, 01:43 PM   #9
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Quote:
Originally posted by alucard13
does anyone know what the highest temp would be on the mugen Mr-12? the guy i bought it from said 220.
The general rule of thumb for motor is between 230 and 270. I'd say if you're running at 220 your fine.
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Old 09-10-2008, 11:20 PM   #10
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Default Re: engine question and radio question

Hi
I think this is an useful discussion. Today more amount of frequency modulations here. Then how to get TV signals in our radio.

-------------
martin

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Old 09-10-2008, 11:29 PM   #11
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Hi. One thing could be a bad cell in your reciever battery. I had a brand new pack that had one bad cell in it. It would charge fine but wouldn't last. This may be the case with yours. With a good fresh charge, everythings fine. But after running once, the pack may not have enough voltage to operate properly. Might be worth testing out that pack. Or, you could just get a fail-safe and that will prevent this from happening again. They aren't expensive and your local hobby shop should stock them or at least be able to get you one. They are worth the money.
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Old 09-11-2008, 12:11 AM   #12
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Quote:
Originally Posted by JetMD View Post
Hi. One thing could be a bad cell in your reciever battery. I had a brand new pack that had one bad cell in it. It would charge fine but wouldn't last. This may be the case with yours. With a good fresh charge, everythings fine. But after running once, the pack may not have enough voltage to operate properly. Might be worth testing out that pack. Or, you could just get a fail-safe and that will prevent this from happening again. They aren't expensive and your local hobby shop should stock them or at least be able to get you one. They are worth the money.
That would be my bet as well - faulty receiver pack. Failsafes are a must have if you are bashing and well worth the money.
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Old 09-12-2008, 09:21 AM   #13
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Failsafes are a great investment and to go even a step further find a good header spring that you can connect to your engine throttle so that if the battery pack goes down it will pull the throttle back to idle. Can never be to safe.

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