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Hello all,

This is my first post here after finding this forum when looking into issues with the Stihl cultivator we have. I will do my best to detail the issue I am a newbie at doing this stuff and am doing my best to figure thing out.

This unit was left out in the elements for some seasons after the previous owner passed. I have since been trying to getting it working again.

I have done the following:

1. Replaced Plug (Gaped to 0.20 also checked for spark which it has)
2. Replaced Carb
3. Replaced Fuel Filter
4. Replaced Air Filter
5. Cleaned exhaust area

It still will not run or even attempt to fire I have not checked spark arrestor or anything else. I am just looking for input on what else I can do to try and get this thing running, is their something I am overlooking?

Compression is about all I see that’s not checked. It’s a good idea to pull the muffler...you can see if it’s plugged up. Is this a 2 or 4 stroke motor?

gilephor said:

It still will not run or even attempt to fire I have not checked spark arrestor or anything else. I am just looking for input on what else I can do to try and get this thing running, is their something I am overlooking?

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I've got one of these....bought it perhaps 10 years ago, and it works great. Pulling the muffler is a good thing to try, since if this thing has been setting out in the weather, the muffler may be rusted and clogged. If it has good compression, pulling the starter rope should require a "hefty" pull. Check to see if the cylinder is getting fuel....pump the primer bulb several times...making sure that you see fuel entering the bulb, give the engine several pulls at full choke, then pull the plug to see if it is "wet"....if not, carb or fuel lines, etc., is an issue. If the plug is "wet", you probably have an ignition problem....coil, flywheel,etc. If this unit has been sitting out for quite some time, the coil and/or flywheel may have some rust/corrosion built up. If you have a spark tester, that should tell you if the engine is getting any spark. If the coil area seems clean, check that the coil gap is set to between .005" to .007".

It is a 2 cycle, and thanks for the suggestions so far. I will check the other areas mentioned as well.

Take off the air filter cover and filter, and pour a dribble of fresh fuel directly into the carb throat, and try to start.

Pull it a bunch, holding the throttle open/trigger depressed, and see if you can get the engine to hit/turn over.

Try this, and get back to us...

When you have the muffler off peak into the exhaust port and look at the piston and cylinder for wear like scratches or grooves.

Fish said:

Take off the air filter cover and filter, and pour a dribble of fresh fuel directly into the carb throat, and try to start.

Pull it a bunch, holding the throttle open/trigger depressed, and see if you can get the engine to hit/turn over.

Try this, and get back to us...

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Did this and no luck the piston looked good to me, no visible issues to my eye. Took the muffler off, inside it was a gas water mix i think not sure why that would have been there. After drying it out and cleaning the spark arrestor with a torch still nothing. Although after taking the exhaust off and putting it back on when i first tried to start it it would let out a whine. It is not doing it now after it set a while but was.

I even went so far with the fuel to buy the Stihl 93 octane premixed stuff and it does not seem to have helped. Any other place to look. When i am trying to start though it seems to be spitting fuel out through the air filter and smoking a little.

Did we overlook seeing if the spark plug is actually firing. I Read through the thread again and don’t see where this was confirmed.

Well, i do not have a tester but there is spark to the boot as confirmed by a shock to the finger When putting my finger on the bottom of the boot and having my son pull the cord it shocked me

Lol....you supposed to have your son hold the wire. A good way to check without tools is to remove the plug and insert it in the boot and hold the plug against the engine block and spin the engine. It won’t shock you as long as the plug is grounded. Look at the gap for the spark. Should be blue..ish in color.

gilephor said:

Well, i do not have a tester but there is spark to the boot as confirmed by a shock to the finger When putting my finger on the bottom of the boot and having my son pull the cord it shocked me

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OK...if you can "feel" the spark, the next thing to look for is the "timing" of that spark. There is a flywheel "key", a small half moon shaped "washer" locks the flywheel into position on the crankshaft. These sometimes sheer, and the flywheel rotates away from the proper timing of the spark. If you remove the nut holding the flywheel to the crankshaft, you should see a "slot" on the flywheel and a matching slot on the crankshaft. If these do Not line up, your spark will not be occurring at TDC of the piston.
Also, did you pull the plug after several cranks to see if it is "wet"...indicating that fuel IS getting to the piston??

Dump out the gas again, and pull the plug again, and totally dry it all out again.

Then when you are sure it is all dried out internally, still put no fuel in the tank. Put the plug back in and attach the wire. But with the air filter off, pour a dribble of clean fuel into the carb again, and pull/try to start as you would normally.
See if after some pulling, you get the engine to fire up and run until it burns off the dribble of fuel.

Try this test before you start tearing the trimmer into pieces.

Let us know what you find.

Ok so I bought an in-line tester hooked the long end into the boot, the other end to the spark plug seated in the cultivator. I could not see any light or anything from the tester. So does this mean I need something like this? When I did pull the plug it was wet and smelled of gas.

http://www.boxstoreparts.com/Stihl-Ignition-Module-Coil-4140-400-1308-4140-400-1308.htm

Correction: it is getting spsrk so i will try other suggestions.

gilephor said:

Ok so I bought an in-line tester hooked the long end into the boot, the other end to the spark plug seated in the cultivator. I could not see any light or anything from the tester. So does this mean I need something like this? When I did pull the plug it was wet and smelled of gas. http://www.boxstoreparts.com/Stihl-Ignition-Module-Coil-4140-400-1308-4140-400-1308.htm

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The "Wet" plug should indicate that you Are getting fuel to the piston, so Ignition is the most likely culprit. The picture you posted is the coil, and at a reasonable price. Since you say you felt a "jolt" when you held the plug wire, you might try the tester you bought on another motor...lawnmower, etc., to make sure you didn't buy a defective tester. If the tester checks out ok, and you still get no light, then the coil is a good bet. However, I would still check the position of the flywheel on the crankshaft...those flywheel keys do break....and while you are there hold a metal feeler gauge or small screwdriver near the flywheel magnet to see that it still has good "magnetism", and attracts metal strongly. If the flywheel checks out ok, then the coil is your best bet. Oh, and one more thing....you could have a bad "Start/Stop switch, which is shorted such that you are on "stop" all the time. There is a wire on the side of the coil which comes from the switch, and you can remove that wire to see if the switch is shorting out the coil, and keeping you in Stop mode.

Another tip on small Stihl engines....they do tend to "flood" quickly. I have the MM55, two Stihl trimmers, and two Stihl chainsaws, and they All flood easily. After sitting for some time, I have found that I can only pull the rope once or twice at full choke, then release the choke to get the engine to start with one or two more pulls. If I leave the choke on for more than two pulls, I usually wind up flooding the engine, then I have to pull the plug and let the engine "air out" before trying again.

That's about all I can think of...If none of this helps, you may have to take this rascal to a shop, and let someone who does this for a living, take a look at it.

Dry it all out totally as I suggested,
And you can know with a bit of certainty if your problem is fuel or igntion related.

And dry the plug properly
Modern "fuel" which is nothing like petrol leave an oily deposit on the centre insulator on the spark plug.
This deposit is not conductive in air so you get a spark at the electrodes when you ground the plug to the side of the engine.
However when you put it in the engine, the spark runs down the side of the insulator in place of jumping the gap