Well, I ran into my first real problem with my 11 year old string trimmer. I fired it up this morning to do some trimming around the house and fence line and it started up without incident and ran good long enough for me to get the outside perimiter of my fence. I had just started working inside the fence when I lost power big time. With throttle fully opened I was barily getting idle speed. While this was going on I noticed some light gray smoke from the exhaust.
I shut the machine down, went inside to rehydrate and think out what might have been the problem and what was witin my level of comfort to try to fix. I replaced the plug a couple years ago, so I doubted that would be the problem, but I had a spare on hand just in case.
I had not ever had the spark arrestor off, so decided to try that first. Afer the machine had cooled sufficiently I removed the arrestor (and lost a screw in the process) and noticed a lot of hard black gunk over where there were 4 openings on the muffler. Trying the gunk with my finger, it was not not oily, but dry black carbon.
I went ahead and fired up the machine with the spark arrestor off and got some blue smoke out of the exhaust and the idle was a little rough, but the machine was running and I could work the throttle without the machine dying out.
I was running Stihl HP Ultra with Molabrew stabilizer mixed in the gas with an ounce of techron thrown in the mix for good luck. This was the second time for HP Ultra in the machine.
I took the spark arrestor and put it in a container with some Seafom I had purchased awhile back. Right away gritty chunks of carbon were breaking loose and dropping into the solution. I let things sit for about 20 mins and went about doing something else. When I came back most of the hard chunks of carbon had dissolved in the Seafoam. This was my first experience with Seafoam, but it looks like it works very well with hard carbon. The nice thing is other than a light lighter fulid smell, it wasn't terribly noxious.
I dried off the screen and examined it in the light. About 95% of the carbon got cleaned off by the Seafoarm and it will probably be alright to use the screen once i get a replacement screw.
I shut the machine down, went inside to rehydrate and think out what might have been the problem and what was witin my level of comfort to try to fix. I replaced the plug a couple years ago, so I doubted that would be the problem, but I had a spare on hand just in case.
I had not ever had the spark arrestor off, so decided to try that first. Afer the machine had cooled sufficiently I removed the arrestor (and lost a screw in the process) and noticed a lot of hard black gunk over where there were 4 openings on the muffler. Trying the gunk with my finger, it was not not oily, but dry black carbon.
I went ahead and fired up the machine with the spark arrestor off and got some blue smoke out of the exhaust and the idle was a little rough, but the machine was running and I could work the throttle without the machine dying out.
I was running Stihl HP Ultra with Molabrew stabilizer mixed in the gas with an ounce of techron thrown in the mix for good luck. This was the second time for HP Ultra in the machine.
I took the spark arrestor and put it in a container with some Seafom I had purchased awhile back. Right away gritty chunks of carbon were breaking loose and dropping into the solution. I let things sit for about 20 mins and went about doing something else. When I came back most of the hard chunks of carbon had dissolved in the Seafoam. This was my first experience with Seafoam, but it looks like it works very well with hard carbon. The nice thing is other than a light lighter fulid smell, it wasn't terribly noxious.
I dried off the screen and examined it in the light. About 95% of the carbon got cleaned off by the Seafoarm and it will probably be alright to use the screen once i get a replacement screw.
