When do I need to replace the piston?

Piston service life on karting 2-strokes: IAME X30 approx. 15–20 running hours, Rotax MAX approx. 25–30 hours, TM KF approx. 15–20 hours. Warning signs: loss of compression, piston skirt scoring, discoloration at the ring. Always replace piston, ring, small-end bearing and gudgeon pin together — never mix new/old parts.

Which carburettor for which engine?

IAME X30: Tillotson HW-27A (senior) or HL-334A (junior). Rotax MAX: Dell'Orto VHSB 34 (factory setup). TM KF: Dell'Orto VHSH 30. Vortex KF: IBEA F3. Honda GX 4-stroke: Walbro WYK. For carburettor swaps always match cylinder tuning and exhaust — otherwise no gain, only loss.

How do I set the karting carburettor correctly?

H (high) and L (low) needles: start with factory settings from the workshop manual. On track, adjust in 1/8-turn steps: rich if the engine four-strokes, lean if it hesitates on throttle. Ambient temperature and air pressure influence setting — set on the day, not the day before. Rule: rich rather than lean — lean runs kill pistons.

Why does the engine not start?

In order of frequency: (1) no fuel — check tank + fuel line for air, (2) spark plug wet or fouled, (3) carburettor flooded (too rich), (4) ignition weak — check coil resistance, (5) piston seized, (6) crank seals leaking. Systematic diagnosis: spark plug out → is there a spark? → is it wet? Only then start on the carburettor.

Do I need to run the engine in?

Yes — first 30–45 minutes at moderate load, no full throttle. Break-in cycle for X30 / Rotax: 3 × 10 min with 5 min cooling breaks, no full throttle over 6000 rpm. New rings need controlled load to seal properly. After break-in first check clearances and change oil (2-strokes: mix ratio unchanged).

Engine & Carburettor

Engine parts & carburettors for kart racing engines

Whether 2-stroke racing engine, 4-stroke entry-level engine or shifter unit: at keep-racing you will find complete engines and all replacement and wear parts for the common kart engine families — Rotax, IAME (X30, Waterswift, Reedster, Gazelle, Leopard), TM, Vortex, Yamaha, PRD and Honda GX for the 4-stroke segment. Plus matching carburettors Dell'Orto, Tillotson, Tryton and Walbro including all repair and tuning parts.

What you will find here

Complete engines — Honda GX 4-stroke for Bambini and training karts, IAME X30 and Waterswift, Rotax MAX, TM KF/KZ, swissauto (phased out).
Engine parts — cylinders, cylinder heads, pistons, piston rings, connecting rods, crankshafts, crankcases, cooling, water pumps, exhaust, gaskets, starters, balance shafts — sorted engine-specifically.
Ignition — PVL ignitions, coils, spark plugs (NGK, Bosch, Champion, Denso).
Complete carburettors — Dell'Orto VHSB, Tillotson HL/HW, Tryton for Rotax, Walbro WB for Honda.
Carburettor parts — main jets, needle jets, floats, needle valves, atomisers, gaskets — the typical wear and setup parts.
Carburettor accessories — intake manifolds, reed blocks, filters.

Engine-specific categories

For the widely used IAME engines we maintain dedicated sub-categories — X30, Leopard, K25, Reedster KF/KFJ, Waterswift, Gazelle — so you can go directly to the right part without browsing every spare parts list.