# Craftsman Weedwacker No Power



## irjr (May 30, 2008)

Hello everyone, I'm new to this forum, and I have a problem too.

I have a Craftsman 31cc Weedwacker model 316.798221 which I've had for about 3 years now, and has never had a problem until last week when it ran out of gas, and I quit for the day. The next day I gassed it up, and it seemed a bit harder to start than usual, but when it did start, it revved up fine as it ever did, but when I got it near a weed, the power bogged down and the engine died. Tried it again a few times, and same results. Just no power to it. I did a search of this forum, but could not find an identical situation. What should I check, or should I just go looking for a replacement? So far I have made no adjustments, but did change the spark plug (Still no power).

Before the problem, this wacker outwacked the couple of wackers I owned previously, so I would rather get this one going again if the cost doesn't outweigh a new one......... JR


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## geogrubb (Jul 28, 2006)

I would suggest removing the muffler and cleaning the spark arrestor, they get clogged with carbon and zap power, while the muffler is off look through the exhaust port and check the piston and cylinder walls for scoring, also if you haven't replaced the fuel lines, they are due to be failing also. Have a good one. Geo


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## pyro_maniac69 (Aug 12, 2007)

might also be needing the diaphrams replaced, since you ran it out of gas and let it sit, the gaskets and diaphrams might have dried up and are not working properly now


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## phillipmc (Jan 27, 2008)

When it ran out of gas was the engine on wide open throttle ? When you said it was a bit harder to start then usual do you mean it was harder to pull the cord or was it just being stuborn ? Reason I ask these questions is because when 2 cycle engines run out of fuel they also run out of lube. And you know what happens to engines without enough lube. A good rule of thumb is when you are useing 2 cycle and you have it WOT just before it runs out of fuel the RPMs will pickup all of a sudden. Release the throttle right then and refuel with properly mixed fuel/oil. Also Make sure before you start using it the tank is full of fresh fuel/oil mix and keep a check on it. Thats why I like 2 cycle equipment where you can look at the tank and see your fuel level.


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## wiretwister (Jun 1, 2008)

*Also check exhaust port for carbon blockage.*

I have a echo trimmer that I use professionally that loses power occasionally, but the spark arresstor is always clean, but the exhaust port is partially clogged with carbon. Also I have to occasionally clean the carbon from the pistons and combustion chambers on all my trimmers.


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## oscaryu1 (Mar 25, 2007)

When you gassed it up, was it straight gas?


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## irjr (May 30, 2008)

Yes, when it ran out of gas, it seemed to pick up a lot of speed just before it died. And stubborn, not hard to pull when trying to restart. Also, now that I remember, I thought I heard something like a compression squeek a couple of times when I pulled the cord, but my hearing isn't all that good anymore, so maybe it was something else.

As for the carbon build up, I didn't see any, but I'll take another look to be sure.

When I refilled, it was gas-oil mix, not straight gas. And a look with the muffler gizmo removed shows a bit of scarring on the side of the piston, but not real bad. Do these things have head gaskets, cause I sure don't see any sort of head/cylinder separation area?


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## phillipmc (Jan 27, 2008)

the actuall cyclinder seperates from the lower end of the engine where the crank is. When you remove this the piston stays on the connecting rod and with the crank. Their is normally a gasket between the 2 with 4 bolts holding the cylinder down to the bottom end of the engine. One a side not 99% of the time its cheaper to just replace the trimmer then it is to fix it.


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## hankster (Jan 1, 1998)

If there is any damage to the piston, it and the cylinder is most likely shot. This model uses a single end supported crank so the rod is removable when you take off the cylinder. The cylinder is held on with 2 bolts. New pisiton and cylinder would cost about $55... the piston includes the rod already attached to it.


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