alec
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Posts: 37
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Post by alec on Aug 22, 2019 4:11:39 GMT -5
I have a Homelite super xl 925. Had a broken fuel line so I replaced that. Was running great in a log for about 2 minutes then just completely stopped. I have great spark with the plug grounded on the muffler. I primed the saw with a shot of premix gas directly to the cylinder without any cough whatsoever. I didn’t think it had bad gas but changed it with fresh non ethanol gas anyways. Still no change. I was going to check the flywheel shear key tomorrow. The saw feels like it has tremendous compression due to my sore arm. I’ll pull the muffler to check the cylinder anyways. Any other suggestions since I’m kinda stumped?
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Post by undee70ss on Aug 22, 2019 4:13:11 GMT -5
Take a known good plug, cut the ground strap off, check for spark.
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Post by undee70ss on Aug 22, 2019 4:15:16 GMT -5
Just because you have spark in open air, doesn’t mean it’s sparking under compression, do my test and post results.
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alec
Gots Tree Cred
Posts: 37
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Post by alec on Aug 22, 2019 11:17:24 GMT -5
What’s the ground strap on a spark plug? Do you mean the electrode ?
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Post by Clasec on Aug 22, 2019 12:50:59 GMT -5
What’s the ground strap on a spark plug? Do you mean the electrode ? It is the metal piece that is welded by the threads that the center electrode jumps spark to. You could also bend it straight.
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alec
Gots Tree Cred
Posts: 37
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Post by alec on Aug 22, 2019 16:48:01 GMT -5
Ok I cut off the ground strap. I get a big blue spark from the electrode to the muffler up a 1/2 “ away
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Post by undee70ss on Aug 22, 2019 18:00:49 GMT -5
Ok I cut off the ground strap. I get a big blue spark from the electrode to the muffler up a 1/2 “ away Ok, that mean you have plenty of spark. Try a new plug. I would also pull muffler and inspect piston.
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Post by Brennan on Aug 23, 2019 1:46:19 GMT -5
It seems your timing may be out or your plug is bad. My xl-123 has something similar happen after I replaced my fuel line but the plug was to blame. The ceramic insulator around the center electrode had come loose and would close the spark gap up.
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alec
Gots Tree Cred
Posts: 37
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Post by alec on Aug 23, 2019 11:33:28 GMT -5
I changed the plug. So I know it’s not that. I’ll check flywheel key and piston
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alec
Gots Tree Cred
Posts: 37
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Post by alec on Aug 23, 2019 11:51:00 GMT -5
So I took off the flywheel. The shear key is intact and there. I took the muffler off. Piston looks ok. A little scoring at the bottom but doesn’t look bad.
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Post by edju1958 on Aug 23, 2019 12:49:52 GMT -5
Do you ave a compression tester so tat you can test the compression? Ed
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Post by alec8707 on Aug 23, 2019 15:13:07 GMT -5
Checked compression. It’s really low for a 925. I got 100. I’m surprised because pulling it over felt like it always does
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Post by alec8707 on Aug 23, 2019 15:13:49 GMT -5
Anybody know a good source for oem piston/rings. Haven’t pulled the engine apart yet but should probably start looking
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Post by alec8707 on Aug 23, 2019 15:19:37 GMT -5
I put a little 30 weight oil in the cylinder and the compression read 200. I guess that’s a ring or piston.
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Post by 5terrysupersaws on Aug 23, 2019 16:07:07 GMT -5
Anybody know a good source for oem piston/rings. Haven’t pulled the engine apart yet but should probably start looking 77cc or 82cc ? ... UT and Serial number ? Post a picture of the piston and rings through the exhaust port .
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alec
Gots Tree Cred
Posts: 37
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Post by alec on Aug 23, 2019 19:33:34 GMT -5
I have a Homelite super xl 925. Had a broken fuel line so I replaced that. Was running great in a log for about 2 minutes then just completely stopped. I have great spark with the plug grounded on the muffler. I primed the saw with a shot of premix gas directly to the cylinder without any cough whatsoever. I didn’t think it had bad gas but changed it with fresh non ethanol gas anyways. Still no change. I was going to check the flywheel shear key tomorrow. The saw feels like it has tremendous compression due to my sore arm. I’ll pull the muffler to check the cylinder anyways. Any other suggestions since I’m kinda stumped?
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Post by Brennan on Aug 23, 2019 19:51:47 GMT -5
It almost seems like you have a lack of oil in the cylinder from the premix or you have a stuck ring. I wouldn’t go ordering things until you have pulled it apart and given everything a good cleaning
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Post by edju1958 on Aug 23, 2019 20:11:31 GMT -5
The 925's are a hot item right now & I doubt you'll find an OEM piston & cylinder at a reasonable price.Fortunately I know a guy who has a vast supply of Homelite parts & he might just have what you're looking for.I just looked on Ebay & there's nothing for a 925. Ed
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Post by edju1958 on Aug 23, 2019 20:19:23 GMT -5
If you do have a stuck ring,rather than tear the saw down,try a 50/50 mix of acetone & ATF.I had a Mac saw that was starting to seize on me & I added that concoction into the cylinder & it' came free in no time.I just kept pulling it over every 15 min.or so. Ed
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alec
Gots Tree Cred
Posts: 37
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Post by alec on Aug 24, 2019 3:49:27 GMT -5
The saw is 40 years old it’s not a mixed gas issue.Yes obviously I need to tear it down before I order anything but it’s a good idea to start looking early since I also checked eBay and saw nothing. UT=10415 serial#5189T190
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