Lets build a saw together

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Is that groove on the flywheel side where the seal rides? From the looks of your picture the bearing was slipping on the crank.
You know what, it could be, but I'd have to go out and look at it again to be sure. I don't think the bearings were slipping the crank, but they are not in good shape so they may have been before the saw sat for awhile.
 
I realized tonight that even with the parts saws I bought, I'm still going to need a gasket set, and if I'm going to make a parts order, I think I'm gonna build 2 saws. Technically I will have nearly enough parts to build 3, but 2 will do.

One of the cases I'm getting is a 670 single coil, And I think I am going to order a 272 pop up cylinder and piston for that one.

The cases I have now are about all the was good off the saw other then the covers, So I think the second saw I'll build will be with my cases and whatever parts I can salvage from the 625, with the 670 top end.
 
Well, my plan was to use the single coil case I just got instead of my existing cases, and build it up with a 272 top end, however either of the top covers I have fit the single coil case since the front mounting hole if further forward on the cover. There is defiantly not enough material on the case to drill and tap it, so I am debating maybe trying to build it up with JB weld and add a nut into the JB weld to secure the top cover to the single coil case. Or, I could get a chinese 272 top cover and see if it will fit, as I believe most of the chinese parts are for single coil saws.

Either way, I still want to build 2 saws from the parts I have now, so I think the first one will be a standard 670. I'll use the better of the twin coil cases that I have, and the better cylinder (I have 2 670 cylinders now), and do some porting and put it together and see how it does.
 
I went ahead and tore down the 670 cases I got today. Both cranks are in better shape then mine, but the one from the single coil saw looks to be the best. Actually, that whole saw seems to be in the best shape, so if I can figure out the top covers, I may try to use that case yet.

Left to right, 625, 670 single coil, 670 twin coil

tempImagetOj1re.jpg

tempImagemVVEKl.jpg
 
Just get an aftermarket top cover or an nice used oem one that will fit right. Not worth the hassle imo to retrofit the wrong one. Good choice with the single coil case.
 
I was just watching a Tinman video about bulletproofing the 266 saws, and he made comment that the single and fuel coil flywheels and cranks are not interchangeable, so that fries my plans of using the nicest crank in the saw build.
 
Knocked the bearings out of both twin coil cases today. I'm not happy with any of the bearings, as none of them turn smoothly.

I noticed that the 670 cases both have a second line in the oil tank, I'm guessing a vent?

I need to finish cleaning these cases and get ready to start assembly. I'm thinking about investing in a ultra sonic cleaner that the parts will fit in.

The 625 never had a oil line in it when I got it. Ordering some parts tonight to get this build on the road. I was gonna order farmertec parts but don't really want to wait for them to show up, so will probably get SKF bearings, and seals/lines from highway.

tempImagedTf7bG.jpg
 
Just get an aftermarket top cover or an nice used oem one that will fit right. Not worth the hassle imo to retrofit the wrong one. Good choice with the single coil case.
I think I've got enough parts to build both of the twin coil cases into saws. I'll save the single coil for a later project and build a 272 out of it.
 
Well, I ran into a hiccup that I’ve dealt with before and forgot about.

When I did the cylinder on my Stihl 361 I couldn’t find any motoseal around here. Yesterday while we were in the “city” I looked everywhere I could think of and no luck. And tonight I’ve had no luck finding anyone that will ship it to Alaska if I buy online.

When I did the Stihl I ended up using red RTV but I don’t really want to do that on this saw. So I’ve got to look into other options I can get. I can get red, blue, orange, black and gray RTV but none of those seem ideal.
 
Knocked the bearings out of both twin coil cases today. I'm not happy with any of the bearings, as none of them turn smoothly.

I noticed that the 670 cases both have a second line in the oil tank, I'm guessing a vent?

I need to finish cleaning these cases and get ready to start assembly. I'm thinking about investing in a ultra sonic cleaner that the parts will fit in.

The 625 never had a oil line in it when I got it. Ordering some parts tonight to get this build on the road. I was gonna order farmertec parts but don't really want to wait for them to show up, so will probably get SKF bearings, and seals/lines from highway.

View attachment 1031315
Man, you've got parts and multiple saws torn apart if front of you. How do you keep everything straight? I tore apart a log splitter engine that had seized for the fun of it and I don't think I could put it back together.
 
Man, you've got parts and multiple saws torn apart if front of you. How do you keep everything straight? I tore apart a log splitter engine that had seized for the fun of it and I don't think I could put it back together.
I’ve actually got 3 of the Jonsereds spread out across the bench, as well as a poulan wild thing, and various other parts I tend to never put away, and currently my 460 rancher is torn apart on top of it all because the chain brake locked up 🤣. I’ve also got the engine to my wife’s suburban all torn apart right now too, but that’s a whole bother crock of beans. I’ve always been pretty good at reading stuff down and remembering how it all goes back, even if I don’t work on it for awhile.

With these saws, I marked all the major stuff to which one it came out of so I can put it back together
 
Well, I ran into a hiccup that I’ve dealt with before and forgot about.

When I did the cylinder on my Stihl 361 I couldn’t find any motoseal around here. Yesterday while we were in the “city” I looked everywhere I could think of and no luck. And tonight I’ve had no luck finding anyone that will ship it to Alaska if I buy online.

When I did the Stihl I ended up using red RTV but I don’t really want to do that on this saw. So I’ve got to look into other options I can get. I can get red, blue, orange, black and gray RTV but none of those seem ideal.
Any glue used for cases on a 2 stroke bike will work on a saw as well. Yamabond, Honda bond. Three bond. I like loctite 518 for the head to case Sealand myself. Dirko ht works well too, which can be had at a stihl dealer.
 
While waiting for parts to finish putting the bottom end back together, I decided to check out the cylinders today.

I didn’t notice before that the 625 is a open transfer cylinder and both of the 670 cylinders are closed transfer. I believe both of the 670 cylinders I have are after market.

The 625 cylinder has crazy carbon build up on the roof and in the exhaust port. It comes out pretty easy with a small flathead screwdriver, but it’s the worst I’ve seen.

Pistons on the 625 cylinder and the cleaner/nicer of the 670 cylinders fit nice with no slip, but the more used looking 670 piston is two tight for either of the cylinders at the base of the piston. It will go, but takes quite a bit of effort and sticks in the cylinder. I don’t like it.

I think I’ll use the 670 cylinder and order a hyway pop up piston for a 266 to put in it.

78B9CEA3-3009-44C4-AA1D-7EDD85E398FE.jpeg

3289619A-414C-4F3B-BC6B-D6D6904A6731.jpeg
 
Any glue used for cases on a 2 stroke bike will work on a saw as well. Yamabond, Honda bond. Three bond. I like loctite 518 for the head to case Sealand myself. Dirko ht works well too, which can be had at a stihl dealer.
I’ll have to check the Stihl guy in Fairbanks next time we go, but I doubt they will have it since they don’t service saws.
 
Back
Top