Charkov T150-K tractor startup

Startup of a Charkov T150-K tractor which I used to own (sold now to Bulgaria). The sequence is about as follows: - turn on main switch - open fuel petcock for two-stroke starter engine - press electro starter switch to start starter engine - leave two-stroke starter engine running for short time to build up oil pressure in main engine - couple two-stroke starter and main engine - pull up throttle for main engine until it runs - stop two-stroke engine - close fuel petcock for starter engine The whisteling sound is the massive turbo-charger touring down BTW. Main engine is 9.15l, 6 cylinder V engine at 165BHP.