Better to idle or shut off and on?

[4570Man]

The starter in my truck is junk. I idle it a lot. I don’t care to idle or start the tractor so it’s a whatever I feel like deal. I probably tend to let it idle for 5 minutes and shut it off for much more.

 

[4570Man]

There's a safety aspect, too. If you're stopped on a slope, it'd be better to shut the engine off and put it in gear as well as have the brake on if getting off the tractor.

For my cars and pickup, if I'm stopped where I know a light pattern and know it's a long one, off goes the engine. Stopped to pickup books at the drive-through at the library. Engine off until I get the books. No sitting in vehicle with AC or heater on if wherever you're going isn't open yet. Shut the engine off.

Ralph

Gas isn’t that expensive. Unless the conditions are pretty good I’m letting it run.

 

[BillyDBrown]

Thanks guys for all the informative replies!

 

[rbtjr]

The owner's manual for our MX5800 says "don't idle unnecessarily". This is because the "particulate matter" in the exhaust fumes will not be fully burnt at idle, which leads to accumulation of the "PM", which leads to more frequent regeneration cycles. I guess that this would be an argument for turning off our MX and restarting it versus leaving the tractor idling.

 

[Ford850]

Keep in mind the original question is for a Honda GX390 on a 2 wheel BCS. On my BCS with a Briggs Vanguard, I let it idle for a minute or two, but shut it off if it is longer than that. Restarting a warm engine causes little engine wear.

 

[CobyRupert]

Just curious. I have heard (read?) that "working 2-cycle engines hard" helps in reducing carbon buildup in their exhaust ports/mufflers, thus idling would promote that buildup. But would frequent stopping/starting (and not working the engine hard for an extended time) promote carbon buildup?

Steve

I think this is true for many motors. My question is: Is this a problem? So what? That is, unless it builds up to the point it plugs something (like a screen on a 2 cycle). Can you just run it hot once in a while so it gets burnt out?
I've always heard you need to run diesels under load (>60%) or you'll get wet stacking (carbon build up), but I don't know why this is bad? -Again can't you run it hot once in a while to burn it out?
I'd like to hear answers as to what long term wet stacking problems may occur as a lot of my tractor time is running a log winch where it sits idling for a majority of its time as one is pulling cable out, hooking chains, winching, then a short drive, then more idling as one measures, cuts log lengths, unhooks, etc....

 

[Thomas]

Less than 10 mins I shut it off except during real cold months.

 

[davrow]

For my tractor I don't even think about it... just do what is convenient for the circumstances. For 2-strokes, I hate how they sound, so off they go whenever possible.

 

[NibbanaFarm]

The Honda is very quiet at idle, doesn't produce many fumes when warm, and hardly uses any fuel. But pulling that starter rope gets tiring. I save my shoulder and let it idle.

 

[TractorGuy]

90% of the time I leave mine running. The only time I reduce the RPMs to idle is just before I shut it off. My little tractor is hydro so engine speed remains where I set it. If I am getting off the tractor I will disengage the PTO, set the parking brake, and reduce the engine speed to 1200 - 1500 RPMs.

On my backhoe I will drop the bucket, put in neutral, and use the hoe throttle to increase the RPMs above idle.

Engines with flat tappet type cams do not get adequate lubrication at long term idleing. Leaving them at idle for too long is a good way to wipe out a cam.

If my machine is going to sit more than a few minutes I usually let it idle long enough to let the turbo spool down and shut it off.