# Troy-Bilt Trimmer Stopped While running at full throttle



## boilermaker52 (Apr 16, 2008)

Hello,

My Troy-Bilt 2-Cycle Gas Trimmer died on me the other day and I can't seem to find the problem. It is model TB20CS. I was trying to extend some line and was running the trimmer at full throttle for a few seconds when it suddenly quit running. Attempts to restart it failed immediately after and some time later after it cooled. Plunger and choke switch all work, fuel is full and flowing and the spark plug looks good. Something failed during the full throttle run that is preventing this thing from running. Any ideas? Is this thing worth repairing? The trimmer is about three years old.


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## pyro_maniac69 (Aug 12, 2007)

is it the style with the spring assist recoil?


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## justin3 (Apr 10, 2007)

I would start by checking for spark, its possible your coil may have gone out on you or you may just need a new spark plug. I remember a similar issue on an eager Beaver model and it turned out to be a bad plug. Got Spark? if you do then next remove the muffler and look for scoring on the piston skirt and give the rings a tap to make sure they are free and not stuck.


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## boilermaker52 (Apr 16, 2008)

Yes, it is the type with the spring assist.


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## pyro_maniac69 (Aug 12, 2007)

they had major issues with the spring assited units. The clutch would loosen up, and than shear the flywheel key, which you can't replace just the flywheel key, you need to replace the entire flywheel which is only about $25

now when you roll it over, do you hear a knocking sound?


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## hankster (Jan 1, 1998)

Pull off the muffler and look for scoring on the piston/cylinder.


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## boilermaker52 (Apr 16, 2008)

No knock when I roll it over, except what I think is the pick-up tube in the gas tank. I'll check behind the muffler tomorrow.


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## pyro_maniac69 (Aug 12, 2007)

boilermaker52 said:


> No knock when I roll it over, *except what I think is the pick-up tube in the gas tank*. I'll check behind the muffler tomorrow.


this confuses me


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## boilermaker52 (Apr 16, 2008)

This fuel pick-up tube is what is making the clunk noise when I turn it over. No other noises. 

I checked the cylinder/piston and there are no marks or damage there. Anything else to check?


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## hankster (Jan 1, 1998)

I belive by "turning over" it is meant to pull on the recoil. Does the engine turn over as it normally did or does the recoil pull out freely without the "spring assist" activating.


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## boilermaker52 (Apr 16, 2008)

There is tension from the spring assist.


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## boilermaker52 (Apr 16, 2008)

Tried a brand new plug, no go. I am out of options with this thing.


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## hankster (Jan 1, 1998)

Pull the carb off and then pull off the black carb mount (4 screws). On the back of the carb mount is the reed, it is a silver piece of spring steel. Make sure it is still in place covering the intake. Sometimes the reed will come loose or break.


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## boilermaker52 (Apr 16, 2008)

Reed was still in place and not broken.


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## hankster (Jan 1, 1998)

OK, lets go back to basic troubleshooting to narrow it down. You've already done some of the hard work but we need to find out what system is causing the problem. First make sure it has spark.... if so make sure you use a new plug DJ7Y or RDJ7Y. Now to see if it is a fueling problem, pour a bit of fuel into the carb and try to start it... make sure the choke is closed when you try to start it. Some of these have an automatic choke that may not be closing the choke fully.


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## boilermaker52 (Apr 16, 2008)

I have a new plug DJ7Y, can I just plug the wire to the plug with it not screwed in and watch for a spark?


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## hankster (Jan 1, 1998)

You have to ground the plug to the engine. I do recommend a gap type spark tester as it's easier to use but in most cases you can just use the plug.


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## gfezz (May 19, 2008)

Greetings,

I have a Troy Built blower/vac that has always been hard starting till it just refused to start, maybe 10 hrs on it...

I observed a no spark condition, searched the net and found this thread and a couple others...

I tear into it having a hunch what might be wrong, I reset the air gap on the ignition module to flywheel using a piece of wax paper slipped between them, noticeably closer than it was before...

I used a battery drill/piece of hose to spin up the crank, a nice blue spark now.

I did notice that it would not begin to spark until a certain amount of rpm was reached, more than i would have guessed, so a brisk pull on the rope is a must....

Final assembly done and it fired on the third pull...

I cant swear that air gap was the issue, but something i did made it start better than it ever has before...


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## mtbahsZ (Jun 29, 2008)

Coming in new to this forum, and taking a few steps back, I have a troybilt with spring assist. It was running at full throttle when it ran out of gas and stopped with a bang. Now the spring assist no longer has tension and does in fact knock when the starter handle is pulled. Is this an easy fix if I order parts myself??


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## hankster (Jan 1, 1998)

I would suspect that the clutch came loose and the flywheel key has sheared. Not that hard to fix except getting the clutch tight when putting it back together.


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