Carson 1:8 RC model car Nitro Buggy 500204029 User Manual

Engine break-in is the most important step to assuring that your 
engine is fast and reliable throughout its life. Put simply: DON’T SKIP 
THIS PART! 

The engine is pre-set from the factory for break-in. Use a “FAT BONE” 50 
090 5034 or platform and place the car so that the wheels are off the 
ground and free. 

Make sure the throttle is set at neutral with your radio. Place the glow 
heater onto the glow plug and give the recoil a sharp pull (picture 4). 
Do not pull it more than twelve inches! More than that may break the 
cord and this is not covered under warranty. It is better to give the 
recoil short sharp pulls rather than long ones. If the pull-start cord gets 
stuck, rotate the flywheel a little bit with your finger. This should make 
the cord automatically recoil. Within a few pulls, the engine will start 
with a good puff of smoke.

If the engine has trouble idling at the rich setting, turn the idle screw 
clockwise 1/8th of a turn at a time. This will increase the idle allowing 

the car to break-in properly. Try to do this in a well-ventilated area, 
such as your driveway. Unburned oil from the fuel will accumulate 
under the exhaust, so be prepared. Let the car idle like this for 2 - 3 
tanks of fuel checking the engine temperature every 2 minutes. Please 
allow a break of 10 – 15 in between filling the tank to allow the engine 
to cool down. You should be able to touch the head of the engine with 
your fingertips and it will be hot, but not uncomfortably so. (Attention! 
Do not touch!) If it seems very hot, richen (turn counter-clockwise) 
the high-end and low-end needles 1/8th of a turn. Always use small 
increments when making these kinds of adjustments.

With the following basic adjustment the engine starts immediately, 
running perfect and rich enough (outside temperature 8°C).

•  Idle stop screw: approx. 1 mm air gap;

•  High speed needle valve: screw in completely, then open 4 full 

turns;

•  Low speed needle valve (linking): flush with the edge of the linking 

arm, then 1 full turn clockwise;

After run-in is finished the high speed needle valve should be open at 
least 3 and 1⁄4 turns. A richer setup is better if outside temperature is 
high.

Drive your car slowly with the rich setting shortly after the break-in 
period avoiding prolonged periods at full throttle. Gradually lean out 
the mixture 1/8 of a turn at a time. The idle will increase the more you 
lean the engine out.

rich

lower

rich

lower

low
RPM

high
RPM