JD motor in snowblower.

[Dmorency]

Maybe someone can help me with this? I purchased this snowblower last year and every time we first start it this is how it runs. Normally it would run like this for about 15-25 seconds, then as if you threw a switch is would suddenly run as smooth as can be.
Lately it is taking longer to smoothen out.
When the motor is warm, it will start normally.
I thought maybe a valve was sticking?

 

[300 H and H]

What engine is in it?

This is normal for a cold start on a diesel with a mechanical injection pump. Till the engine is up to governered speed, the fuel rack is wide open as it would be when running and under enough load to drop the RPM's till the governed speed opens the rack under load.
This over fueling and the rough over fueled running is normal at cold temps.

It doesn't happen warm, as the engine gains RPM's quickly enough that it doesn't slobber all over itself.

 

[waybomb]

Agree with Kirk. But I'd let it sit overnight every night and start it every morning just to hear that cracklin.
And change the oil a lot too because of it.

 

[Dmorency]

Thanks guys. I purchased it last year. I sent a guy to check it out and the seller had the motor running when my guy arrived. He stopped it and restarted it fine. After I had it delivered and started it for the first time,,it scared the crap out of us. But has I said this only happens when the motor is cold. If stopped and restarted, all is fine.
It's a John Deere motor in a RPM TECK blower..

 

[mla2ofus]

May need a new set of injectors. That usually indicates they're not atomizing the fuel properly. That flame out the stack indicates unburned fuel.

 

[300 H and H]

May need a new set of injectors. That usually indicates they're not atomizing the fuel properly. That flame out the stack indicates unburned fuel.

I agree if it smokes under load when warmed up.
I never understood why the people who designed mechanical injection pumps have the fuel rack wide open until the engine loads up and eventually runs way up in RPM's as it burns off extra fuel. It never made any sense to me. All the Bosch inline pumps are this way,

Even the newer computer controlled diesels I own will do this, but not to any were near the extent. A couple of seconds and they settle into a smooth idle.

 

[Dmorency]

Video of the same blower blowing snow. A little black smoke but not bad.

 

[300 H and H]

It only smoked as the governer opened the fuel rack wide open to compensate for peak loading of the blower.
Very normal for a mechanical pump diesel.
It sounds very healthy.

My you have a lot of snow! Here it is nearly a snowless year......

 

[Dmorency]

We have a lot of snow again this year along with wind. Since Jan 1 until today we have had 2 days that we have not had something to work at on our section of highway. 3 times just this week we have had to blow snow from our rail guards.
I feel more at ease now starting this blower after you tell me this is normal because of the pump. Thanks again!

 

[tonkeeparts]

1. Check the Fuel: Ensure that the fuel is fresh, clean, and free from contaminants. Old or contaminated fuel can lead to rough engine performance during startup.
2. Inspect the Spark Plug: A fouled or worn spark plug can cause rough idling. Check the spark plug for signs of wear, fouling, or damage. Replace it if necessary.
3. Clean the Carburetor: A dirty or clogged carburetor can result in uneven idling. Consider cleaning or, if needed, rebuilding the carburetor.
4. Examine the Valve Train: Sticking valves or valve-related issues can cause rough idling. A professional inspection of the valve train may be necessary.
5. Check for Air Leaks: Inspect the intake system for any air leaks that could affect the air-to-fuel ratio. Leaks can lead to poor idling.
6. Adjust the Idle Speed: If your snowblower has an adjustable idle speed, make sure it is set correctly.
7. Fuel Additives: Consider using a fuel system cleaner or additive designed to clean the carburetor and fuel system.

 

[300 H and H]

1. Check the Fuel: Ensure that the fuel is fresh, clean, and free from contaminants. Old or contaminated fuel can lead to rough engine performance during startup.
2. Inspect the Spark Plug: A fouled or worn spark plug can cause rough idling. Check the spark plug for signs of wear, fouling, or damage. Replace it if necessary.
3. Clean the Carburetor: A dirty or clogged carburetor can result in uneven idling. Consider cleaning or, if needed, rebuilding the carburetor.
4. Examine the Valve Train: Sticking valves or valve-related issues can cause rough idling. A professional inspection of the valve train may be necessary.
5. Check for Air Leaks: Inspect the intake system for any air leaks that could affect the air-to-fuel ratio. Leaks can lead to poor idling.
6. Adjust the Idle Speed: If your snowblower has an adjustable idle speed, make sure it is set correctly.
7. Fuel Additives: Consider using a fuel system cleaner or additive designed to clean the carburetor and fuel system.

Do you realize we are talking about Diesel engines? No spark plugs and no carburetor are on Diesel engines.