Forum

[Jim57]

Hi all. I am in need of advice with regards to a starting problem I am having with my 2013 Classic 500 (the model without the kick start). The engine has done 12,500 miles. It has just started with an unpleasant problem when trying to start. It will only start when no choke is used and no use of the throttle. Which may sound ideal. However should it fail to start first time or if switched off after a few seconds then try to restart the problems begin. When turning over it will now fail to start, if I apply any sort of throttle I get this horrible loud knocking or slapping sound coming from the engine when the throttle applied, which will cease when the throttle taken off. Should the engine fire up the sound disappears. If I take the bike for a good run it goes fine and when the engine is really hot it can be switched off and start again without problem. It is just when the engine is cold it more than often fails to start and I experience this horrible knocking, which is quite loud. I have changed the air filter and put the correct spark plug in according to this forum. On checking the plug it appears to be running okay. Can anyone help with the cause of the problem.

[Leon Novello]

I am not familiar with your model, but if it has hydraulic tappets, knocking on start up is usually caused by lack of oil being pumped up to there. Other knocking when cold is usually piston slap, until the engine heats up and the piston expands.

[Tim NZ]

Make certain that the MIL light is working, no blown bulbs? Any fault with the ecu/sensors should create a fault code flash at the MIL light??


Have you tried resetting the ECU?


My initial guestimate would be to check the Throttle Position sensor connections? Or there may also be an issue with the power supply to the fuel pump/fuel filter?? Make and remake the connection to the TPS sensor just in case there is a loose/dirty connection?


Otherwise, for the average Joe, most faults with the ECU or the sensors needs to be seen to by someone with the appropriate test tools, and or by the substitution of parts...