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Post by andrew925 on Jul 7, 2018 21:31:05 GMT -5
Short story is that I overheated my 925 the other day, and therefore need a cylinder.
Have yet to find an actual 925 cylinder, but have found plenty of 923's
Can I make a substitution? or do I need to wait for a 925?
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Post by Clasec on Jul 7, 2018 22:28:35 GMT -5
Short story is that I overheated my 925 the other day, and therefore need a cylinder. Have yet to find an actual 925 cylinder, but have found plenty of 923's Can I make a substitution? or do I need to wait for a 925? You can use a 923 cylinder but you will have to use a thick ring piston if it has a bridged port, also the 923 cylinder will have a decompression valve and lastly the 923 came in 82cc only and the 925 came in 77cc and 82cc. I believe the replacement pistons for the 925 come in 82cc so that would be an option with the 923 cylinder, |
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Post by andrew925 on Jan 10, 2019 23:14:36 GMT -5
Short story is that I overheated my 925 the other day, and therefore need a cylinder. Have yet to find an actual 925 cylinder, but have found plenty of 923's Can I make a substitution? or do I need to wait for a 925? You can use a 923 cylinder but you will have to use a thick ring piston if it has a bridged port, also the 923 cylinder will have a decompression valve and lastly the 923 came in 82cc only and the 925 came in 77cc and 82cc. I believe the replacement pistons for the 925 come in 82cc so that would be an option with the 923 cylinder, Do you have the part number for the Thick-ring piston and rings? Also, how do I spot a bridged port? |
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Post by Clasec on Jan 10, 2019 23:32:06 GMT -5
You can use a 923 cylinder but you will have to use a thick ring piston if it has a bridged port, also the 923 cylinder will have a decompression valve and lastly the 923 came in 82cc only and the 925 came in 77cc and 82cc. I believe the replacement pistons for the 925 come in 82cc so that would be an option with the 923 cylinder, Do you have the part number for the Thick-ring piston and rings? Also, how do I spot a bridged port?  xl923 Cyls 923-925 pistons by Clasec, on Flickr The cylinders pictured are 923's with the oval ports. The bridged port will have a rib in he middle of the port and the port would be rectangular. The piston on the left is a 923 thick ring. Piston on right is a 925 thin ring. This cylinder is for XL103 but the bridged port is close in design.  XL 103 cylinder by Clasec, on Flickr |
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Post by andrew925 on Jan 11, 2019 14:59:22 GMT -5
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Post by Clasec on Jan 11, 2019 21:41:20 GMT -5
Yes, you can use the 925 thin ring piston with the oval port 923 cylinder. The oval port cylinder was advertised by Homelite as putting out more power than the bridged port design and also said it had a quieter exhaust note.
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Post by blythkd on Jan 12, 2019 13:12:15 GMT -5
If you go with the oval port/thin rings option, I'd watch your airflow closely. Don't let the cooling fins get dirty at all, let alone plugged up. I recall some 925's coming through the shop burnt up back in about the mid-80's. My memory is about as long as my....pinky toe, but I do recall a Homelite TSB back around that time where the company suggested rebuilding with the bridged rectangular port cylinder with a wide ring piston. Pretty sure it called out the 49314 piston which only had one ring as well. I'm thinking that piston was maybe an XL-98 piece but not positive.
The bigger bore, oval port setups were getting so hot that the piston rings were losing tension and it's just downhill from there.
If you're worried about giving up 4 or 5 cc's, I wouldn't. I built a 925 a few years ago with the bridged port cylinder and wide ring piston, pretty sure it was a single ring piston too, and it came out very strong. I'd say it'll pull alongside any stock 925 I've ever picked up and I'm more confident in its longevity and durability with the square port/wide ring setup.
Just my .02. It's up to you, either way will work, just kinda depends on what you're looking for.
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Post by undee70ss on Jan 12, 2019 18:05:02 GMT -5
If you go with the oval port/thin rings option, I'd watch your airflow closely. Don't let the cooling fins get dirty at all, let alone plugged up. I recall some 925's coming through the shop burnt up back in about the mid-80's. My memory is about as long as my....pinky toe, but I do recall a Homelite TSB back around that time where the company suggested rebuilding with the bridged rectangular port cylinder with a wide ring piston. Pretty sure it called out the 49314 piston which only had one ring as well. I'm thinking that piston was maybe an XL-98 piece but not positive. This the TSB? It was actually a 921 piston/cylinder, 2 inch bore.  |
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Post by blythkd on Jan 12, 2019 18:20:15 GMT -5
If you go with the oval port/thin rings option, I'd watch your airflow closely. Don't let the cooling fins get dirty at all, let alone plugged up. I recall some 925's coming through the shop burnt up back in about the mid-80's. My memory is about as long as my....pinky toe, but I do recall a Homelite TSB back around that time where the company suggested rebuilding with the bridged rectangular port cylinder with a wide ring piston. Pretty sure it called out the 49314 piston which only had one ring as well. I'm thinking that piston was maybe an XL-98 piece but not positive. This the TSB? It was actually a 921 piston/cylinder, 2 inch bore. I really think there was another TSB on the XL-900 series cylinders/pistons. Seems like the one I'm thinking of called out the 49314 single ring piston. But who knows? Seems like sometimes the more sure I am of something, the wronger I am. Is that a word?
I remember arguing with Dad in my younger years when he was pretty sure of something but I knew he was wrong.....and I was right. Now my son does that crap to me. Guess that's karma! Reaping what you sow? Oh well, at least in my advancing years it's becoming easier to be wrong. Guess that's Low T.
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Post by andrew925 on Jan 21, 2019 4:51:18 GMT -5
So should I do on the oval port or the bridged port option? The oval port option is an easier find on ebay, but it sounds like the bridged port will not only run cooler, but overall preform better.
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Post by rarefish383 on Feb 5, 2019 19:16:10 GMT -5
This the TSB? It was actually a 921 piston/cylinder, 2 inch bore. I really think there was another TSB on the XL-900 series cylinders/pistons. Seems like the one I'm thinking of called out the 49314 single ring piston. But who knows? Seems like sometimes the more sure I am of something, the wronger I am. Is that a word?
I remember arguing with Dad in my younger years when he was pretty sure of something but I knew he was wrong.....and I was right. Now my son does that crap to me. Guess that's karma! Reaping what you sow? Oh well, at least in my advancing years it's becoming easier to be wrong. Guess that's Low T.
As long as you don't say "more wronger". |
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Post by undee70ss on Feb 6, 2019 3:55:48 GMT -5
So should I do on the oval port or the bridged port option? The oval port option is an easier find on ebay, but it sounds like the bridged port will not only run cooler, but overall preform better. I would use what you can find. The are bridged ports, oval ports, with and with compression releases, 2 and 2 1/16 bores. If you use a compression release cylinder, you will have to plug it. |
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Post by hotshot on Jun 12, 2020 15:25:37 GMT -5
You can use a 923 cylinder but you will have to use a thick ring piston if it has a bridged port, also the 923 cylinder will have a decompression valve and lastly the 923 came in 82cc only and the 925 came in 77cc and 82cc. I believe the replacement pistons for the 925 come in 82cc so that would be an option with the 923 cylinder, Do you have the part number for the Thick-ring piston and rings? Also, how do I spot a bridged port? I understand this is a very old thread, but why can’t you recommend running the 82cc thin ringed XL925 piston with the bridged port XL923 cylinder? |
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Post by Clasec on Jun 12, 2020 17:36:28 GMT -5
Do you have the part number for the Thick-ring piston and rings? Also, how do I spot a bridged port? I understand this is a very old thread, but why can’t you recommend running the 82cc thin ringed XL925 piston with the bridged port XL923 cylinder? If I recall correctly Homelite said there was a possibility of ring clipping when useing the thin rings in a bridged port cylinder. Probably because they didn't hold their shape as well in the large port. |
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Post by hotshot on Jun 14, 2020 7:49:03 GMT -5
Thanks for the quick reply & information!
Have always used the maximum “60% of bore”
rule to widen the exhaust when porting a saw with
pinned rings, but never considered the thin rings to
be such a variable.
I remember the older Lawn Boy mowers used a bridge
gap design by having three holes, but the rings were
standard fat ones (1/16” thick) & not pinned.
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Post by Superxl newbie on Dec 30, 2020 2:05:35 GMT -5
Old post i know sorry, inherited old green and white super xl, wanting to know if 1 of these larger jugs will bolt to my saw to increase power? I believe i have 58cc and these are 82cc. Is this possible or is 58cc as big as i can do? Thanks for info
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Post by Clasec on Dec 30, 2020 2:33:24 GMT -5
Old post i know sorry, inherited old green and white super xl, wanting to know if 1 of these larger jugs will bolt to my saw to increase power? I believe i have 58cc and these are 82cc. Is this possible or is 58cc as big as i can do? Thanks for info The 82cc cylinder's bolt pattern is larger so it is not really an option. It may be possible to install a XL400 68cc piston and cylinder as the stroke is close. The register in the crankcase may have to be checked for the correct size also. |
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Post by blythkd on Dec 30, 2020 9:52:55 GMT -5
What about XL500 parts? It's a 2" bore if I'm not mistaken, giving it nearly the cc's of a small bore 925, it's just a bit shorter stroke. I haven't done it and I'm no 500 expert, I'm just assuming most of the engine architecture is the same between it and the SXL.
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Post by sweepleader on Dec 30, 2020 10:48:55 GMT -5
XL-500 uses the larger, than the SXL, crankcase for the longer stroke, same one as the XL-400. The early XL-500 parts do not interchange directly with the XL-400 unless they are grouped together with similar year parts. The XL-400 and the XL-500 are different bores but both larger than the SXL, which is larger than the XL-12.
All use the "same" architecture and look externally identical.
This SXL topic should be moved to a new thread if anyone wants to discuss it further.
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Post by Superxl newbie on Dec 30, 2020 12:20:29 GMT -5
I hope to be a regular on here, very interesting machines and very knowledgeable people on here. Having alittle trouble navigating but will get the hang of it. I work long hours. But i am goin to turn this saw into the baddest saw i can would love a 24inch bar. If i can find new thread i will join u guys there thanks for the info.
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