It seems that when I'm starting the bike after it has sit for a week or so, the first 2 seconds when the engine catches and runs, I hear what sounds like either a piston-pin or a rod knock. I figure this is due to the way the engine is designed to startup (which is quickly), or perhaps how I'm starting the bike. When I turn the ignition on, I wait about 3 seconds for the speedo/tach to boot up. Then, I turn on the engine kill switch and immediately see the check engine light come on, along with the fuel pump pre-presurization. The bike fires up immediately.

My question is, should I be hearing the rod knock sound for 2 seconds on startup? My feeling is that the cold idle is set too high (it is currently 1600-1800), or that I should just start the bike immediately. If I start the bike immediately, it doens't start right away, and I have to crank on it for 2-3 seconds. But those 2-3 seconds allow for oil pressue to build at the expense of reduced battery and starter life. And sometimes in hot weather, if I don't allow for the fuel pump pre-presurization to occur, the bike misfires and coughs during starting.

 

What your hearing is a lifter that has bled down during that long week between starting.....continue starting the bike like you do, let the pump do it's thing because while it is pressuring up the map sensor is taliking a reading of the altitude for proper opreation.

Don't be alarmed....no damage is being done.

 

Well, thanks! I guess this is a classic case of "stop thinking so much and just drive it."