Is it possible??? 3/8 low-profile chain on old Echo CS-330EVL

[telecasterfool]

Be careful - I don't know of any rim sprocket that is 3/8 Lopro (picco) Maybe someone knows better. 3/8 Lopro should be a spur drive. Rim sprockets can be 3/8 or .325, and can be 7 tooth, 8 tooth, or 9 tooth. There are also 3 different inner spline sizes - just to make things more complicated.

 

[dboyd351]

How bout just buy a new sprocket like the one that came on the saw and pair it with the bar/chain the OP wanted to buy in his first post?

If thats too easy, we can ponder all the potential options and confuse the crap out of ourselves.

 

[atpchas]

Be careful - I don't know of any rim sprocket that is 3/8 Lopro (picco) Maybe someone knows better. 3/8 Lopro should be a spur drive. Rim sprockets can be 3/8 or .325, and can be 7 tooth, 8 tooth, or 9 tooth. There are also 3 different inner spline sizes - just to make things more complicated.

Example: https://www.ebay.com/itm/222842247239

 

[Scrap Farm]

Be careful - I don't know of any rim sprocket that is 3/8 Lopro (picco) Maybe someone knows better. 3/8 Lopro should be a spur drive. Rim sprockets can be 3/8 or .325, and can be 7 tooth, 8 tooth, or 9 tooth. There are also 3 different inner spline sizes - just to make things more complicated.

I have found one rim that is 3/8 LoPro for sure. GBR7L7 by GB (Australia). Not easy to come by stateside, unless it's sold as a private-label deal under a different brand. This might be the rim that comes with the Rotary 12045 drum I mentioned earlier, but I have yet to confirm it. It's a STANDARD spline rim, apparently.


I spoke to a guy at Oregon tech and he said he's pretty sure that their 18720 rim is LoPro. The Oregon catalog doesn't really specify, but 18720 has a SMALL spline bore, so it would make sense since small hub >> small saw >> small chain. The tech wasn't too positive about it, so he's going to have "the old guy" call me and hopefully sort it out.

Example: https://www.ebay.com/itm/222842247239

The rim sprocket above (Stihl 0000-642-1240) is indeed 3/8LP, but it is a MINI spline, which won't fit my saw. As I understand it, the MINI spline size is exclusive to Stihl and won't fit any other brand -- as of now, anyway. Correct me if I'm wrong on this.

 

[telecasterfool]

I have found one rim that is 3/8 LoPro for sure. GBR7L7 by GB (Australia). Not easy to come by stateside, unless it's sold as a private-label deal under a different brand. This might be the rim that comes with the Rotary 12045 drum I mentioned earlier, but I have yet to confirm it. It's a STANDARD spline rim, apparently.
View attachment 1205838

I spoke to a guy at Oregon tech and he said he's pretty sure that their 18720 rim is LoPro. The Oregon catalog doesn't really specify, but 18720 has a SMALL spline bore, so it would make sense since small hub >> small saw >> small chain. The tech wasn't too positive about it, so he's going to have "the old guy" call me and hopefully sort it out.


The rim sprocket above (Stihl 0000-642-1240) is indeed 3/8LP, but it is a MINI spline, which won't fit my saw. As I understand it, the MINI spline size is exclusive to Stihl and won't fit any other brand -- as of now, anyway. Correct me if I'm wrong on this.

Great info - thanks! I've never seen a rim that was 3/8 LP.

 

[Scrap Farm]

To update, I just ended up ordering a spur sprocket (Oregon 28000) and a WoodlandPRO 14" ArborMAX Lite bar/chain combo plus a spare Oregon chain from Bailey's.

I haven't been able to get solid info on the rim sprocket options because the clutch drums are discontinued and the companies that made them (Oregon, Rotary...) have scrubbed their records of any indication they ever existed. You can still get NOS clutch drums for rim sprockets for the saw, but I want to be able to run low-pro/narrow-kerf chain. At this point I'm pretty sure the drums out there have a SMALL SPLINE, and the only low profile rim I've found (GB GBR7L7) is for a STANDARD SPLINE.

I'll continue to look into rim sprocket options for the Echo CS-330EVL, but in the meantime I need to get this saw back in action before the cold comes so I'm just going with a spur sprocket for now. If I find any new info on the parts I've found or discover new part numbers, I'll report back.

Thanks everyone for your input.