Stihl weed trimmer very hard to turn over with pull cord

[Paddy]

hello,

I have a Stihl FS 55 weed trimmer and it's 12+ years old. I have had good performance from this beast. At the end of this season, I planned to run the tank dry to store it for the winter. It was easy to start all season. But it it sat for 2 months before I got around to getting it ready. When I tried to start it, the compression was so high, I could hardly get it to turn over. I pulled the plug and she spins freely.

Where to start first? Remove exhaust to inspect clean? Could the crankcase be filled with oil/gas, and if so, how to purge?

 

[Roadworthy]

I've experienced the same issue with Stihl weed trimmers and Echo chainsaws. If you can remove the plug and have it spin freely keep trying. Pull through several times without choke or throttle activated to blow excess fuel out the spark plug hole. Reinstall the spark plug. Try a few more times without priming, no choke, no throttle to confirm no fuel in cylinder. It should start pulling normally at some point. At that point attempt to start it. Don't forget to mix oil with fuel of course. Sometimes I get this kind of response from one use to the next through the season.

 

[Richard001]

I've experienced the same issue with Stihl weed trimmers and Echo chainsaws. If you can remove the plug and have it spin freely keep trying. Pull through several times without choke or throttle activated to blow excess fuel out the spark plug hole. Reinstall the spark plug. Try a few more times without priming, no choke, no throttle to confirm no fuel in cylinder. It should start pulling normally at some point. At that point attempt to start it. Don't forget to mix oil with fuel of course. Sometimes I get this kind of response from one use to the next through the season.

Yes, roadworthy got it right. You have excess fuel/oil in the crank case. The fuel does not compress so when you try to turn over the engine, the compression is so high, that you are lucky to be able to turn it over at all.

As he said, you need to get the excess fuel out of the crankcase. Remove the spark plug, remember make sure the the on/off switch is off. Some of the newer ignition systems don't like to be operated without a spark plug connected.

Make sure that the choke is off and hold the throttle wide open and pull the engine over until you no longer see fuel spitting out of the spark plug hole. Then after cleaning the excess fuel of of the plug, put it back in and try to start without using the choke. Holding the throttle wide open at this time may help it to start.

If no start, check the plug again, if it is fouled with fuel, repeat the step above.

If you really emptied the fuel tank, then it is a mystery why your engine crankcase is flooded. Typically the flooding of the crankcase happens when there is fuel in the tank and the temp cycling will cause the fuel to be forced into the crankcase. The fuel cap has a one-way valve on it. Air can come in, but it can not get out. If the tank is subjected to cycling temps, the air in the tank expands when warm and when it cool, it will suck in more air. Over time, this can cause excess fuel to be forced into the engine.

Richard

 

[Paddy]

to be clear, the tank was full and it was stored outside under a concrete deck. Dry, but the sun does shine on it with the low sun angle. So it appears the fuel expanded from the tank and leaked into the crank case. Can the piston be position such that I can turn it upside down to drain the crankcase through the sparkplug hole?

Thanks everyone!

 

[Roadworthy]

It is highly unlikely you'll be able to drain the crankcase through the spark plug hole. There won't be a lot of fuel in there anyhow. Just remove the plug, turn off the ignition, and pull the cord several times to clear the fuel. It doesn't take much.

 

[Paddy]

thank you. I'll give it a try tonight

 

[kenmbz]

had this with my echo, just pulled the plug as above and cleaned the plug, a couple of pulls and good to go.
I hope this is the issues you are facing too.

 

[StarWolfQTP]

Hello, I didn't want to start a new thread since I have the same issue with my FS94R. Did you ever find a solution? I'm getting a resistance that I can feel with a wrench when the plug is in. Any help would be appreciated thanks!

 

[ROUSTABOUT]

I twist up a paper towel, light it, stick in sparker hole, whoof, and excess fuel is gone.

 

[ROUSTABOUT]

I worked on multiplied thousands of two strokes and still have no fondness for them. Get some starting fluid, black top, not red top, and spray in exhaust if you have one that won't hit off. Just a quick shot, spark plugs are important too. I had two new plugs and it ran completely different on each plug. Swapped them to and fro three times, so spark plugs do make a difference. I often removed plugs and heated with a propane torch to burn off fouling and to start with a hot plug. Them guys getting water in the two strokes was a bear, the biggest problem I had. I never pour the last drop out of a gas can, but they would. Couple that with a drizzly rain day and no tops on gas cans.