New Exmark Engine Dieseling

[AdamE]

I've got an Exmark Radius with the Exmark engine and 17 hours on it. Every once in a while, I'll get a small backfire when I turn it off and then the other day it dieseled for a couple of seconds when I turned it off. Otherwise, it runs great.

I always let it idle for 4 or 5 minutes before shutting down.

Is this something to be concerned with? What might be causing it?

Thanks.

 

[MParr]

I've got an Exmark Radius with the Exmark engine and 17 hours on it. Every once in a while, I'll get a small backfire when I turn it off and then the other day it dieseled for a couple of seconds when I turned it off. Otherwise, it runs great.

I always let it idle for 4 or 5 minutes before shutting down.

Is this something to be concerned with? What might be causing it?

Thanks.

I had the same engine on my former Toro Timecutter HD54. I would get the backfire. I very seldom got the run on condition. I figured it was running a bit too rich. If I had kept it, I would have put some hotter spark plugs in it (BPR5ES). It may be the nature of those Chinese made Loncin engines.

 

[fixit1ddh]

When You turn key off if at idle. At the same time turning key off flip throttle to half. That should eliminate any shut off problems.

 

[sivicman]

I'm glad I got a Kawasaki engine.

 

[slomo]

I've got an Exmark Radius with the Exmark engine and 17 hours on it. Every once in a while, I'll get a small backfire when I turn it off and then the other day it dieseled for a couple of seconds when I turned it off. Otherwise, it runs great.

I always let it idle for 4 or 5 minutes before shutting down.

Is this something to be concerned with? What might be causing it?

Thanks.

Does your engine have the anti-back fire carb solenoid? If so sounds like yours is not working. Engine OFF, turn the key and listen for a small click around the carb area. Turning key on should make a click again. Or remove the solenoid and do the same. Better this way as you can watch the plunger do it's thing with the key cycling.

Idling down a mower engine is not recommended per Briggs. Briggs says run at full beans for max longevity all the time. These are not car engines. At low revs there is insufficient cooling taking place. These are air cooled and reach full temp in 1-2 minutes.

Also clean your cylinder cooling fins yearly per your engine manual. Neglect this and you are asking for engine damage.


slomo

 

[AdamE]

Does your engine have the anti-back fire carb solenoid? If so sounds like yours is not working. Engine OFF, turn the key and listen for a small click around the carb area. Turning key on should make a click again. Or remove the solenoid and do the same. Better this way as you can watch the plunger do it's thing with the key cycling.

Idling down a mower engine is not recommended per Briggs. Briggs says run at full beans for max longevity all the time. These are not car engines. At low revs there is insufficient cooling taking place. These are air cooled and reach full temp in 1-2 minutes.

Also clean your cylinder cooling fins yearly per your engine manual. Neglect this and you are asking for engine damage.
View attachment 57325

slomo

Interesting points.

I've always heard (and I'm no expert by any means) that you should let an air-cooled engine idle for a bit because they run hotter than a water-cooled engine and idling lets it cool down so the oil doesn't bake on. Old wives tale?

More reading is in order...

Thanks.

 

[MParr]

I copied this from an operators manual for the engine stop procedure on the Loncin made Toro/Exmark engines. It states to cut the engine off at full throttle.

Shutting Off the Engine​

1. Disengage the blades by moving the blade-control switch to the OFF position (Figure 20).
2. Engage the parking brake.
3. Move the throttle control to the FAST position.
4. Turn the key to the OFF position and remove the key.

Caution​

 

[bertsmobile1]

Interesting points.

I've always heard (and I'm no expert by any means) that you should let an air-cooled engine idle for a bit because they run hotter than a water-cooled engine and idling lets it cool down so the oil doesn't bake on. Old wives tale?

More reading is in order...

Thanks.

That is because you are listening to he wrong shaved monkeys
Water cooled engines get idled for a few minutes before shut down
Air cooled engines get shut off at full throttle.
The air flow is not directly proportional to the engine speed, it is a exponential relationship so at 1/2 speed you are getting less than 1/4 of the air flow

 

[slomo]

Interesting points.

I've always heard (and I'm no expert by any means) that you should let an air-cooled engine idle for a bit because they run hotter than a water-cooled engine and idling lets it cool down so the oil doesn't bake on. Old wives tale?

More reading is in order...

Thanks.

As Bert said, air flow for cooling suffers when you idle the engine. Briggs says run at max revs for max durability. Shy away from idling a mower engine.

slomo

 

[AdamE]

Good info!

I just re-read the owner's manual and what do you know - I found this...

4. Place the throttle midway between the “SLOW”
and “FAST” positions.
5. Disengage the PTO.
6. Allow the engine to run for a minimum of 15
seconds, then turn the ignition switch to the
“OFF” position to stop the engine.

Thanks all!