I have the L120 which is an earlier version of your D170. It has the B&S twin. It was always a difficult engine to start until about mid-second season when I changed the air filter and used a dental mirror to look down the air horn and inspect the choke. When the lever was in the full choke position there was a significant gap between the choke plate and throttle bore. I adjusted it tobe FULLY closed when lever was in full choke, and it now starts much better.
The trick to starting on mine, when cold, is to have throttle in full slow idle position and choke fully closed. Crank, and within two or three spins it will fire off. Once running, advance throttle to 1/3 and retard choke to ~1/2. After about 30 seconds to a minute, place choke fully off and when the engine is ready, start mowing.
With a hot engine, it will usually fire without the choke, however, if it doesn't, just move the choke lever fully forward and then fully back while cranking and it will start right up. It's now at 587 hours and it keeps on going...
HTH,
Paul
The trick to starting on mine, when cold, is to have throttle in full slow idle position and choke fully closed. Crank, and within two or three spins it will fire off. Once running, advance throttle to 1/3 and retard choke to ~1/2. After about 30 seconds to a minute, place choke fully off and when the engine is ready, start mowing.
With a hot engine, it will usually fire without the choke, however, if it doesn't, just move the choke lever fully forward and then fully back while cranking and it will start right up. It's now at 587 hours and it keeps on going...
HTH,
Paul
