Kubota GB13 – GB20 operation and starting: preheating and dashboard
Kubota GB13 – GB20 operation and starting: key positions, preheating and dashboard
Starting a Kubota GB13, GB14, GB15, GB16, GB18 or GB20 always goes smoothly with the correct preheating time — even in winter. In this article: the key positions, the official preheating times per temperature, the meaning of the dashboard lights and how to protect the engine against overheating and misuse.
Suitable for the entire series: Kubota GB13 (D9/DA5/N), GB14 (B9), GB15 (B9/S), GB16 (K/FK/H), GB18 (K/FK) and GB20 (K/FK).
Kubota GB key positions and starting procedure
The ignition switch has four positions: off (engine stopped, key removable), on (driving position), preheat and start (springs back automatically to "on"). To start: sit in the seat, clutch engaged, gear and PTO in neutral, throttle slightly open. Turn the key to "preheat", hold for the time listed in the table below, then turn on to "start". Never run the starter motor continuously for more than about ten seconds; if it doesn't start, wait a moment and try again.
| Outside temperature | Preheating time |
|---|---|
| Above 0 °C | 2 – 3 seconds |
| 0 to −5 °C | 5 seconds |
| −5 to −15 °C | 10 seconds |
With a warm engine, preheating is not necessary. If the engine turns over sluggishly in severe frost, the oil is too thick: the owner's manual recommends 10W-30 instead of SAE 30/15W-40 for winter — see our oil and fluids guide.
Kubota GB dashboard: what the warning lights mean
With the key in the "on" position, two indicator lights of the easy-checker light up: the charge warning light (battery) and the oil pressure light. Both should go out as soon as the engine is running. The glow plug light only lights up during preheating and starting — if it doesn't light up, first check the contacts on the glow plug rail before replacing the glow plugs. Versions with bi-speed turn have an additional light that lights up when the system is engaged.
If the oil pressure light stays on while the engine is running: switch off immediately and check the oil level. If the charge warning light stays on, the alternator is not charging — a known issue on this generation, see the troubleshooting guide. The fuse box contains 5, 10 and 15 amp fuses; spare ones are part of the standard equipment.
Kubota GB engine protection: temperature and idling
If the needle of the temperature gauge enters the red zone, the coolant is approaching ± 125 °C. Reduce throttle, let the engine cool down at idle and look for the cause: coolant level, V-belt tension (± 7 mm deflection at 10 kgf) and contamination of the radiator screen and grille. Never switch off the engine immediately when overheated, and never open the cap of a hot radiator.
Another peculiarity of these pre-chamber diesels: after prolonged idling or a series of short cold trips, moisture and unburned fuel remain in the muffler, causing persistent white-blue smoke at the next start. The remedy from the owner's manual is simple: give the machine some real work every now and then so the exhaust gets properly hot, and avoid prolonged idling.
Kubota GB running-in and daily checks
Before every working day: check engine oil and coolant level, tire pressure, operation of brakes and lights, and inspect for leaks all around. After the first 50 operating hours (or after purchase without a service history), perform the running-in service with fresh engine oil, oil filter, transmission oil and hydraulic filter — the complete schedule is in our maintenance article.
Starting problems in winter?
Nine times out of ten it's the glow plugs or their wiring. The glow plug for the D905/D1005/D1105 engines (SKU-55209, € 13.50) is available separately — but first check the thread size (M10 or M8) of your old glow plug. If the starter motor itself is no longer running smoothly, there's a new starter motor for the GB series (SKU-129043, € 138.50).
