Question

what will happen if we put diesel insted of petrol in our bike ?

Answer 1

Diesel is much harder to ignite than petrol and relies on very high compression (5-10 times greater than a petrol engine) to superheat air in the cylinders and thus trigger ignition. Consequently the fuel is injected just prior to TDC (top dead centre). Petrol is injected on the downstroke, compressed on the upstroke and burns when ignited by the spark plug.

Diesel contains much longer chain hydrocarbons and is much "heavier" and less volatile. It doesn't burn completely in the petrol engine resulting in smoking (when part of a fuel mixture) to complete non-running as the mixture is enriched.

Petrol introduced into a diesel engine burns immediately it is blown in and with the wrong dynamics, making the engine run badly and unevenly, potentially causing damage.

My wife once inadvertently put unleaded in a diesel van she was using - but only at about a 20% mix. It ran okay.

Answer 2

If it's only a litre or so in the fuel tank, not too much. Will run a bit rough and smoke a bit but otherwise should be ok.....