Solo 644

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Mar 7, 2006
Messages
7,252
Reaction score
6,510
Location
USA
A friend of my wife just gave me a Solo 644. P&C looked good so I commenced to cleaning about 1/2 pound of gunk from the inner reaches of the saw. Saw starts and runs OK. I had to dress the bar rails and decided to paint it as well. the back end of the clutch cover is broken out and I need a new rim sprocket. This has .325 chain and rim sprocket is .325 8 tooth. Is that too high for this saw? I was surprised it was not a 7 tooth.
 
A friend of my wife just gave me a Solo 644. P&C looked good so I commenced to cleaning about 1/2 pound of gunk from the inner reaches of the saw. Saw starts and runs OK. I had to dress the bar rails and decided to paint it as well. the back end of the clutch cover is broken out and I need a new rim sprocket. This has .325 chain and rim sprocket is .325 8 tooth. Is that too high for this saw? I was surprised it was not a 7 tooth.
I'd say it's adequate and the saw has enough power. The .325 is a smaller tooth than your usual 3/8. I found that the standard for most saws of that displacement and output is either a 7 tooth 3/8 or an 8 tooth .325 sprocket. So manufacturers seem to consider them about equal in performance requirement.
 
That saw family (644, 651, 656 etc) came with a 7T sprocket: some models came with a rim sprocket and others with a spur one. I am 90% sure the 644 came with a rim type sprocket.
So it's running an aftermarket sprocket. ;)
 
Interestingly there is no 8 tooth sprocket listed in the manual. http://www.solo-germany.com/gba_download/9644131/web/9_644_131_en_web_11_2007.pdf
So yeah, I agree, definitely aftermarket. But like I said, the saw should pull the chain just fine. I see people switch to a smaller pitch so they can get a bigger sprocket and get the chain speed up. Unless you're running a really big saw, speed always beats tooth size.
 
I don't know the history of the saw. It is a rim sprocket, not spur. Had it running today but it is DUMPING bar oil through the oiler. Thought I had a leak where the hose enters the oil pump but I resealed it and it's not leaking. Pump is set to minimum. I even machined a restricted nozzle for the outlet - the hole dia. is 0.04" / 1.016mm, and it still seems like a lot is coming out. Need to check the ipl to see if something is missing. Thanks for the ipl link SoopermanLuva!

The plus side is, I'm getting about 13,500 at wot and still have a good 4 cycle sound. H screw is out about 1-1/4". Bad side is, I didn't get to cut with it yet because of all the oil.

Oh, yeah, I got three good Stihl and two Oregon chains with it. I noticed the bar shows 66 DL but the chains are 67 DL - like maybe they added a link for the 8T rim.
 
Found the oil leak - from where the oil pump attaches to the oil tank. I cleaned the surfaces and applied a thin bead of rtv. Will check in the morning. If OK, maybe I'll finally get to cut with it tomorrow. I repaired the back of the clutch cover with stainless mesh and JP weld. Seems pretty strong. If it cuts strong with the 8 tooth, I'll use it. If I go to 7 tooth, the chains may be 1 dl too long.
 
Back
Top