Stihl Blower suddenly not starting

I have a Stihl BR-420c blower that is about 5 years old with light use. It has always started easily on third pull. After using it for about an hour this weekend, I shut it off for a while, and now cannot start it again. It doesn't even try to fire when I pull cord.

I checked the start switch, pulled the plug, replaced gas and tried starting fluid, but no luck. This happen to me years ago with an older model I used to own. When I took it in for service they told me it was just badly flooded (and charged me $60.). I have no idea how it became flooded, but it never happened again. I suspect that I may have the same problem again.

I pulled the plug and waited 3 days, but still nothing.

Any suggestions would be greatly appreciated.

Thanks, Scott.

 

Have you replaced the spark plug?

Also you should test the ignition to see if your getting spark.

 

No - I plan to pick up a new spark plug in the morning. I'm working on my blower now, so I will check for a spark.

Could the carb become flooded to the point that I would need to clean it out?

Thanks.

 

Do you put it away with gas in it and let it sit that way for a while? If so thats a bad idea.

 

The most common way to flood your type of engine is to just pull it several times with the choke engaged. Usually if you do not get the engine to pop off or try to start with a few pulls with the choke, then you should take the choke off and try starting that way. It's unusual but not impossible for the type of carburetor you have to just flood.

 

I disassembled entire engine and everything looks good. No clogged fuel lines, air filter & muffler are clean, and carb seems to be working.

I swapped the spark plug out with one from my trimmer, but still nothing.

The only other thing it could be is the ignition. Will probably take it to the dealer at this point since I don't have a spare ignition to try.

Thanks for all your help!

BTY: I drain the gas from all my equipment at the end of the season, and then run the engine until it stops. Finally I pull the starter cord until the cylinder is in compression so the exhaust port is closed.

 

Problem Solved!

But first the rest of the story...

So I called the dealer and they are backed up 3 weeks and charge $30 for an estimate (bummer!). The leaves are getting deep so I went to my neighbors to borrow their blower which happens to be the same model as mine. Unfortunately it also would not start even thought it was running fine a week ago.

Having no options, I took both blowers to the dealer. The service guy asked what was wrong and I told him they just won't start even thought they were running fine recently. He then asked if I minded if he tried to start them. Of course I didn't mind, that is why I brought them in for service. As I exclaimed "sure you can try, but..." he pulled the starter on my blower and it fired up! Then he grabbed my neighbor's blower and fired it up with one pull! I was both astounded and embarrassed at the same time.

He told me to never use the choke because it tends to flood small engines. If it doesn't start with the choke off, then try the choke only once then set it off again. Also keep the throttle on full when starting. I'm still confused because I've always used the choke to start my blower without any problems, so I'm not sure why it caused the engine to continually flood so badly this time.

Sorry for the long post, but I felt compelled to share my humbling escapade.

Hope this helps someone else.

Live & learn...
- Scott.

 

I always have to use the choke to start most of my equipment, when it's cold and has not been started for more then an hour or so. I rarely see equipment that will start easily cold, without choking or priming. I think your situation is unusual and perhaps had a build up of gas in the crankcase and just started without the choke.

 

I agree. I've always used the choke to start a cold engine, but I did not realize it could flood the engine so easily. In the future I'll be careful to only use it once or twice max.

 

I generally get best results starting with the throttle wide open too...if you aren't already.

 

Prior to this incident I only set throttle at half open per instruction manual, but now I will set it on full based on the dealer's advice. Thanks.

 

I have an Echo that's about a week old and it never seems to start with the choke in the cold position.

The key to me seems to pull the cord once with the choke in cold position and the throttle abot 50% (doesn't start) then move the choke to the run position and it fires right up.

After looking at the choke plate I just don't see how enough air can make it through that pin hole....

 

I had to start my Stihl blower cold several times this weekend. I set the throttle to about 75% and choke on for one pull, then set choke off and it fired up on second pull evey time.

I also noticed the choke plate on my Stihl only has a pin hole for air. Seemed a bit too restrictive to me as well.

 

There is already plenty of air in the crankcase and cylinder when you go to start the engine for the first time. You need the extra rich mixture to get the engine to fire off when it's cold. If it does not pop off after a pull or two with the choke, then try it without the choke. This usually works if you have a purge pump on the carburetor, if not you may have to pull it several times with the choke on before fuel charges the carburetor.

 

One: choke and pull once. Remove choke and pull until it starts. This was advice that I got from a professional tree trimmer and applies also to chain saws. Always had problems before. Now it is a snap to start UNTIL....

Two: the blower suddenly wouldn't start, paid $90 to find out that the spark arrestor screen was completely plugged. Google Stihl Blower Spark Arrestor Screen to watch a YouTube to see how to clean it.