Rampage MT, Motor Issues, Please Help

[Mikeyost12]

The Rampage MT is my first 1/5 scale gas car I have bought. I am using the Castor 927 oil and for the break in, I mixed the oil to gas at 20:1 per the instructions in the manual. I went through a total of 6 heat cycles (roughly 20-25 minutes, going through a half tank of fuel each time) with no issues at all. I then did two heat cycles where I did go up to full throttle for straight runs.
Now that all of that is complete, I fueld it up and started to just drive normal (a little harder on the truck.) After about 6-7 minutes of driving, I let the truck come to idle and within 20-25 seconds, the motor just stopped on me. I let it cool down and tried to start it and had no luck at all. I did pull the spark plug and replaced it with a NGK CMR7H from Autozone. The car fired up with no issues at all, but again after 6-7 minutes of running, it came to idle and after 20-30 seconds, just turned off (this was the first run on the new spark plug.)
I am still running a 20:1 mix to go through the entire first gallon of gas....... I am not sure what to do to try to fix this issue? Can someone please help me out.... should I maybe go to a 28:1 mix or a 30:1 mix? Should I adjust the high end? Low end? Idle? Any advice in troubleshooting this issue would be greatly appreciated

 

[sunoco]

The Rampage MT is my first 1/5 scale gas car I have bought. I am using the Castor 927 oil and for the break in, I mixed the oil to gas at 20:1 per the instructions in the manual. I went through a total of 6 heat cycles (roughly 20-25 minutes, going through a half tank of fuel each time) with no issues at all. I then did two heat cycles where I did go up to full throttle for straight runs.
Now that all of that is complete, I fueld it up and started to just drive normal (a little harder on the truck.) After about 6-7 minutes of driving, I let the truck come to idle and within 20-25 seconds, the motor just stopped on me. I let it cool down and tried to start it and had no luck at all. I did pull the spark plug and replaced it with a NGK CMR7H from Autozone. The car fired up with no issues at all, but again after 6-7 minutes of running, it came to idle and after 20-30 seconds, just turned off (this was the first run on the new spark plug.)
I am still running a 20:1 mix to go through the entire first gallon of gas....... I am not sure what to do to try to fix this issue? Can someone please help me out.... should I maybe go to a 28:1 mix or a 30:1 mix? Should I adjust the high end? Low end? Idle? Any advice in troubleshooting this issue would be greatly appreciated

is your gas cap vented? it has to be. if it is not, according to the your post- its simply running out of gas-- just my best guess--

 

[Mikeyost12]

is your gas cap vented? it has to be. if it is not, according to the your post- its simply running out of gas-- just my best guess--

I guess what exactly do you mean by vented? I am using the gas cap and setup that came when I got the car.....

 

[sunoco]

The Rampage MT is my first 1/5 scale gas car I have bought. I am using the Castor 927 oil and for the break in, I mixed the oil to gas at 20:1 per the instructions in the manual. I went through a total of 6 heat cycles (roughly 20-25 minutes, going through a half tank of fuel each time) with no issues at all. I then did two heat cycles where I did go up to full throttle for straight runs.
Now that all of that is complete, I fueld it up and started to just drive normal (a little harder on the truck.) After about 6-7 minutes of driving, I let the truck come to idle and within 20-25 seconds, the motor just stopped on me. I let it cool down and tried to start it and had no luck at all. I did pull the spark plug and replaced it with a NGK CMR7H from Autozone. The car fired up with no issues at all, but again after 6-7 minutes of running, it came to idle and after 20-30 seconds, just turned off (this was the first run on the new spark plug.)
I am still running a 20:1 mix to go through the entire first gallon of gas....... I am not sure what to do to try to fix this issue? Can someone please help me out.... should I maybe go to a 28:1 mix or a 30:1 mix? Should I adjust the high end? Low end? Idle? Any advice in troubleshooting this issue would be greatly appreciated

Its the same thing as trying to pour gasoline out of a gas can with on vent on the can-- no gas comes out.- the redcats- hpi bajas- others have a shi%$y vent set up in the gas cap. Its best to go to a hobby shop- or even a common hardware store- buy a small fitting - drill a hole in the gas cap just big enough to screw the fitting into the gas caps center- then put a gas tube to the fitting- run the hose up to the rear area of the cars -trucks roll bar- its best to put a small hobby fuel filter on the end of the hose-- clean it often- every tank of gas in dust bowl conditions--- 99% chance this will solve your running issue-- simply put-- your carb & engine are starving for gas--

 

[sunoco]

is your gas cap vented? it has to be. if it is not, according to the your post- its simply running out of gas-- just my best guess--

also-- there is a fuel filter in the gas tank. --- sometimes--- this filter can be defective and not allow enough gas to flow into the carb.-- its rare, but it does happen.--

 

[Mikeyost12]

Its the same thing as trying to pour gasoline out of a gas can with on vent on the can-- no gas comes out.- the redcats- hpi bajas- others have a shi%$y vent set up in the gas cap. Its best to go to a hobby shop- or even a common hardware store- buy a small fitting - drill a hole in the gas cap just big enough to screw the fitting into the gas caps center- then put a gas tube to the fitting- run the hose up to the rear area of the cars -trucks roll bar- its best to put a small hobby fuel filter on the end of the hose-- clean it often- every tank of gas in dust bowl conditions--- 99% chance this will solve your running issue-- simply put-- your carb & engine are starving for gas--

So the line that is inside the tank, does that reach down to the bottom of the tank or do you have that line positioned towards the top of the tank? (I ask because we do something very similar with the rc airplanes but that vent line has a copper tube on the inside of the tank that is at the very top of the tank to act as a vent line)

 

[Mikeyost12]

Its the same thing as trying to pour gasoline out of a gas can with on vent on the can-- no gas comes out.- the redcats- hpi bajas- others have a shi%$y vent set up in the gas cap. Its best to go to a hobby shop- or even a common hardware store- buy a small fitting - drill a hole in the gas cap just big enough to screw the fitting into the gas caps center- then put a gas tube to the fitting- run the hose up to the rear area of the cars -trucks roll bar- its best to put a small hobby fuel filter on the end of the hose-- clean it often- every tank of gas in dust bowl conditions--- 99% chance this will solve your running issue-- simply put-- your carb & engine are starving for gas--

Or does that fuel line not even go inside the tank? Is it just connected to the fitting from the outside?

 

[RTA racing team]

I faced a similar issue with my new Rampage. After going through the break-in phase, the engine would be running fine but all the sudden, the engine would stay on but even at full throttle, it was bogging quite heavily. I tried to vent the gas tank, adjust the carb needle. If I would let it rest for a bit, it would start fine, run for maybe a minute or two and same situation. My guess is that it was a carb issue as I read here that these stock carbs were finicky. I then purchase this carb (http://www.davesmotors.com/av990walbrowt990withbearing.html) and the issue is totally resolved.

If the advice above to vent the gas tank does not work, try to play around with the carb would be my guess.

Best of luck!

 

[Mikeyost12]

I faced a similar issue with my new Rampage. After going through the break-in phase, the engine would be running fine but all the sudden, the engine would stay on but even at full throttle, it was bogging quite heavily. I tried to vent the gas tank, adjust the carb needle. If I would let it rest for a bit, it would start fine, run for maybe a minute or two and same situation. My guess is that it was a carb issue as I read here that these stock carbs were finicky. I then purchase this carb (http://www.davesmotors.com/av990walbrowt990withbearing.html) and the issue is totally resolved.

If the advice above to vent the gas tank does not work, try to play around with the carb would be my guess.

Best of luck!

Thank you for the information, with me being new to the gas truck world, is it hard to change the carb?

 

[RTA racing team]

It is very easy. You unfit the gas line from the old carb (you can use a screw as a cap), you un-attach the throttle linkage, you take out the air filter (plastic cover + foam) and you will see 2 screws behind it. You unscrew them as they attach the carb to the motor. You do the reverse to install the new carb without forgetting to fit the gasket between the carb and the engine. It is a 10 minutes process max if you are extra careful.

 

[Larry68]

I guess what exactly do you mean by vented? I am using the gas cap and setup that came when I got the car.....

The gas cap on rampage is vented already. The main mistake I've seen on these trucks is people adjust the carb first. Don't. You can adjust on your controllr the idle setting. Your idle is simply to low. I had the same issue. Easy fix . The other mistake I find is break in on this truck. It is not necessary at all. I have 3 two cycle 1/5th scale. All over a year old and haven' ever even had to change the plug. I did buy a rampage last month and it had a bad motor right from the factory.

 

[G-Man]

The gas cap on rampage is vented already. The main mistake I've seen on these trucks is people adjust the carb first. Don't. You can adjust on your controllr the idle setting. Your idle is simply to low. I had the same issue. Easy fix . The other mistake I find is break in on this truck. It is not necessary at all. I have 3 two cycle 1/5th scale. All over a year old and haven' ever even had to change the plug. I did buy a rampage last month and it had a bad motor right from the factory.

I don't recommend using your radio to adjust your idle, sure you can use the radio to idle up for starting purposes but to use it to set the idle is not the right way to do it. That engine will run and run great without the throttle linkage hooked up at all. I agree it sounds like maybe he needs to adjust the idle a bit higher though. Going to the original poster, Did you read the plug after it shut off? Meaning pull the plug and see what color it is, or was it drenched in fuel? Try bumping the idle up some like others have said. I hold the throttle slightly opened, then turn the idle screw clockwise till it holds where you had the throttle manually opened to. Clean the plug and reinstall, try it again see what happens. If the plug gets wet again, the low needle is slightly too rich then.