View Full Version : Engine knocking..

09-30-2009, 10:02 AM
I have a Toro 60'' with a 27HP Kohler engine. The thing runs great and starts every time but, probably 9 times out of 10 when I shut the engine off it will knock really bad and/or backfire. Has anyone had this problem before or maybe knows what the problem is...Engine has 500hrs on it. Thanks guys!

Two Seasons
09-30-2009, 04:15 PM
We have the same engine on our Turf Tiger.

We let it idle for about 30 seconds before shutting it down. No problems with doing it this way.

09-30-2009, 06:27 PM
Have X-Mark Lazer Z with 27hp Kohler. Had same problem with engine knock after shutting down. Since I run it for 4 to 6 hours straight in the Florida heat, I throttle down real slow and let idle for about 2 minutes or so while my men blow off the mower and I swill large quantities of Gatorade. Works great. You'll get a sense of timing with experimentation for your machine. Some guys idle for a few seconds, others for a few minutes. Do what works for you!

09-30-2009, 07:32 PM
Some will chime in and say the manual states to shut down at 3/4 or higher throttle setting. Well, As said it's what ever works for you. I don't start a engine at 3/4 or do I shut one off at 3/4, A few second cool down works fine. Again..... It's what works for you.

10-01-2009, 06:55 AM
Shutting down at anything significantly more than idle produces engine knock in my machine. I use medium grade gasoline so I don't think it's the low octane rhumba. Whatever causes it, I cure it by idling down slowly and letting the engine run at low idle for a couple of minutes. There's lot's of things in books and manuals that contradict practical experience in the field. Knocking is the spark plug firing on an empty chamber... right? I don't think that's good for the engine. Since the guy who wrote the manual is not out in the field... as Frank Sinatra said "I do it my way".