How to Run a Kart Engine In

“RUNNING-IN” is usually done over three ten minute sessions

1st Session:

Low speed on straights, with *full throttle through slow corners. Ensure some smoke is blown from the exhaust. Allow the engine to cool.

2nd Session:

Low to medium speed on straights, *full throttle through slow and medium Corners. Allow the engine to cool.


3rd Session:

Medium speed with occasional high speed bursts on straights. Allow the engine to cool.

Full throttle through slow corners helps the engine Reach temperatures that the engine normally runs at during a race. Many people do not “load” the engine enough when running in the engine, resulting in seizure the first time the engine is run hard. If the track you intend running your engine in on has long straights, you may want to consider reducing your rear sprocket teeth by about five to ten teeth. If at anytime you feel you may have over accelerated the engine, choke it immediately

Following Sessions:

Run a number of slower laps (similar to a roll-around)To allow the engine to come up to temperature before long sustained full Throttle openings are held; otherwise the

piston may expand at a greater rate Than the cylinder, resulting in a seized engine. Always try and run your engine slightly rich – it only takes ONE run at too lean

a mixture to damage your engine. If the setting is too rich the worst that can happen is a fouled sparkplug! (Slightly cheaper to rectify).

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