Hi guys,
I'm working on a Toro zero turn (Model 75755) with a Toro branded engine # 139-0602. The complaint is that it intermittently backfires on a cold startup. It runs fine once started. I have only been able to replicate the issue twice and both were on a stone-cold engine startup. It backfired immediately upon cranking the engine (not after an extended crank condition). I figured it was either a partially sheared flywheel key (nope) or an overly tight exhaust valve lash keeping the valve open during the compression stroke (nope). It doesn't backfire when you shut it down after the engine gets to operating temp. Any thoughts on what would cause a backfire on a cold start?
Thanks
JShep
I'm working on a Toro zero turn (Model 75755) with a Toro branded engine # 139-0602. The complaint is that it intermittently backfires on a cold startup. It runs fine once started. I have only been able to replicate the issue twice and both were on a stone-cold engine startup. It backfired immediately upon cranking the engine (not after an extended crank condition). I figured it was either a partially sheared flywheel key (nope) or an overly tight exhaust valve lash keeping the valve open during the compression stroke (nope). It doesn't backfire when you shut it down after the engine gets to operating temp. Any thoughts on what would cause a backfire on a cold start?
Thanks
JShep