nopistons10

I just bought the engine brand new from Tower Hobbies. it is for my HPI RS4 evo. It has a lot of hops ups but I wanted more speed. I have almost one tank through the engine. I am getting a brown colored liquid coming out of the turbo exhaust. The engine will also tend to rev higher on it's own without the throttle moving. I would assume this is because it is rich and it sounds as if it needs to be leaned out. When it revs it sounds like it wants to die. I leaned it out a little and it still wants to do it. I have checked everything and can't find a symptom. I think it is because it sits at idle during it's break-in period and doesn't get any throttle to it. It is a more powerful engine than I am used to so I am not sure what is going on with it. My O.S. 18 CV-r never did that. I have messed around with the throttle on my radio and it doesn't fix the problem. Am I having these issues because it is new? Will they go away when it gets broken in?

Bax

My Feedback: (11)

The "brown" stuff is most likely "cooked" oil residue. That's because the muffler chamber gets hot enough to cause the oil to discolor.

As far as your engine's running, it's just not set up correctly. You cannot break it in at an idle. You need to drive the car and get the engine running up and down in RPM. We usually accelerate up to full throttle and then back down, using our parking lot. We gradually work the high-speed needle from a very rich setting towards peak RPM. We'll work the engine as it can accept being leaned until it's just rich of peak RPM. The engine should be able to accelerate up to peak and hold the RPM. If it accelerates and then sags, it's too lean. We'll then get a fine-tune adjustment on the idle mixture and idle RPM settings. They are inter-dependent. Then you'll touch-up the high-speed setting.

Please remember that you have to get the engine warmed up by running a few laps before you can get a real good setting on the high-speed needle. Also remember that the high-speed setting will change from day-to-day, as the weather changes.

nopistons10

Thank you for the quick reply. I was going by the manufactures book by letting it idle for about 3 tanks. I then did what you said and adjusted the speed needle so it is fluch and it operates perfect now. I also drove it in a parking lot for about 2 tanks at low rpm's and high rpm's periodically. I works really good now. No shutting off, no stuttering, no reving on it's own. Again thank you for the good advice and the fast response.