Tightening the bolts on the casing should fix the problem and I believe you said it did, but it only worked for a hour. Is there any kind of gasket that has deteriorated if not maybe think about making one out of liquid gasket sealer. Because it sounds like after running the heat of the engine is changing your seal on the casing. This is due to a poor casting process. The fuel filter on the CS30 is attached to a small piece of pvc tubing inside the tank and is extended to the end of the tank. This is a very poor design. I am having trouble with the engine shutting off when I rotate the trimmer to edge. I am thinking about buying another filter and some tubing then attaching it to a tube tee to send a filter to each end of the tank. But I am afraid one side will suck to much air. The only other way I see to fix the problem is to make sure I keep the tank completly full (which sucks) or to find a more flexable tubing that will allow the filter to fall to each side of the tank easier. Any other ideas, let me know?

lawnboy1022 It sounds like it may have jumped time. To check you can use an ohms meter and have some one attempt to turn flywheel very slow while connecting one lead to spark plug wire end the other to ground. Turn flywheel watching when the contact on flywheel comes to position with coil you should see meter move? Also pulling engine cover look close at key that aliens flywheel if it appears it spun even a little that should be the problem!

I had the same problem on my homelite. There are 2 screws by the carb that I adjusted. One is High and one is Low. Just small turns will make a big difference. This fixed mine, and now it runs fine.

Read through this before you begin. You will do best if the carb is off the engine and on a work bench or other suitable surface. I like to do the work in a large baking pan, less likely for something to roll off and get lost. Refer to the image below. I have added the item # 40.5 for the nut that secures the bowl to the carb. When you remove item 40.5 the bowl should simply pull straight off, you may need to tap the bowl lightly with a plastic screwdriver handle or similar "persuader" to break it loose. Pay attention to what you are doing, my standard advice is use a digital camera and shoot a lot of photos of the carb before you take things loose. And continue to photograph more as you remove items, this will give you something to refer to later WHEN you forget how something was. Have a sheet of paper (or a whole notepad) and write notes, draw sketches, anything to record the details. After the bowl is off, you need to pull out item # 27 to release the float. (you are taking pictures of this aren't you?) The needle valve (item # 30) should lift out of the seat when you pick up the bowl, but it may come loose, so watch it carefully. Pay close attention to the orientation of item # 31 spring clip (more pictures please). Now, I want you to look at items # 17, and 20. # 17 is the IDLE SPEED screw.....do not touch this screw, it sets the low idle RPM only and it's not necessary to mess with it during the cleaning. But # 20, the idle mixture screw, needs to be removed BUT before you remove it, you need to count the number of turns (and fraction of turns) in the CLOCKWISE direction that are required to just barely seat the screw to the bottom of the threaded hole. Write down the number on your note paper, this will be the number of turns CCW you will use as the initial setting when you assemble the carb after cleaning. After the float is off, the needle valve is out, and the idle mixture screw has been "counted" and removed you will proceed to clean the carb. Eye protection is mandatory when using spray carb cleaner, so use the proper safety goggle or face shield. Solvent proof rubber or vinyl gloves are good too. Do the cleaning outdoors or in good ventilation only. No smoking! Using spary carb cleaner (like Carb Medic, example)and the nozzle straw, spray the carb cleaner into every darn hole you see. Using a very fine piece of wire (the bare kind like used on parts tags) and poke it into all the holes to manually dislodge blockage, be careful not to break the wire off in a passage. Spray more cleaner through all the holes. If you have access to compressed air, blow out all the holes and passages. If you don't have compressed air, just let the carb dry thoroughly before reassembling. All the loose parts (bowl, mixture screw, float) need to be cleaned to remove any gunk or varnish film from them. Be careful not to bend any parts of the float where its pin goes or where the needle touches the float. After all is clean and dry, assembly is the reverse of the tear down. And don't forget to change the engine lube oil and filter before you try to run this engine again. Any gas that has appeared in the air cleaner can be mopped out with paper towels, put them outside with a weight on them so the wind won't get them, after the gas evaporates you can toss them into your OUTSIDE trash can. Smoke? Yeah, good possibility. Have the machine outdoors when you restart it. Fire is unlikely (most of the volatiles will be evaporated by then) but you may see some black specks of oil and carbon emerge from the exhaust outlet. That should clear up in 5 minutes or so. May lady luck be holdin' yer hand!