Roper 3.7 tear down and rebuild

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LOL not yet, It's sitting on the bench as we speak. I've been busy building a pinewood derby car and helping my son with his.
j

That's funny. A number of months back, my saw bench was taken over pinewood derby production as well. The bench still has blue overspray on it from the experience. There's the 'shadows' of a hammer and some other tools in the paint....:D

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For on-topic content, one of my buddies has a Craftsman/Roper 3.7 that he's giving me soon. Haven't seen it in person yet. Just in a small cellphone pic. Haven't tinkered with one of these saws since I worked at Sears in the '90s.
 
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One of the parts saw I used to get a runner with had a HS79A on it. It is the same style carb as the original with both H/L adjustments.
 
Great & classic thread for the 3.7 Roper fans

Just curious with a couple of questions, but what was the original Tilly number for the carb that
had only the low speed adjuster (fixed high)? Looks like, from reading through the posts, that
you never did use that one.

Have the thinner metric 1.5mm thick piston rings, versus domestic 1/16" for a 0.0035" difference,
given you any problems on high speed operation (floating)?

I have routinely used the 1.5mm thick rings in a number of saws that originally had the 1/16". I have not noticed any difference in operation. They don't seem to develope as much compression as one would like but, it is the only game in town.

Rings notched for the 1/16" dia. locator pin will develvope great compression. .005" end gap vrs. .070", a no brainer.

I have gotten upwards of a dozen sets from "The Greek" on ebay over the past year.
 
I have routinely used the 1.5mm thick rings in a number of saws that originally had the 1/16". I have not noticed any difference in operation. They don't seem to develope as much compression as one would like but, it is the only game in town.

Rings notched for the 1/16" dia. locator pin will develvope great compression. .005" end gap vrs. .070", a no brainer.

I have gotten upwards of a dozen sets from "The Greek" on ebay over the past year.

Thanks for the info Carl, I understand that sometimes you "have to dance with the girl you brought". I've watched the old school 1/16" thick rings stock/availability dwindle down, and had to ask. So far have been lucky on finding them oversized & fit the ends like you stated, just using a carbide bit & Dremel to notch. Looks like the Greek has his good Caber Homelite rings stock back up to snuff if you need spares.

I'll bet that original Tilly single screw was the old HS-143B model, but maybe will hear back from Opihi59. It would be nice if Tillotson had a database posted on the 'net with HS series venturi sizes like Walbro does, you gotta call them to find out anything.

The tip on the Tilly HS79A is welcomed too, RBurtcher!
 
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I have an older Craftsman 3.7/17 (917.353750). It has a single-screw Tilly HS-143A on it.
 
Through hole connection

One of the parts saw I used to get a runner with had a HS79A on it. It is the same style carb as the original with both H/L adjustments.

There is a side hole that's drilled into the bore on this Tillotson HS-79A Roper carb, coming out right downstream of the throttle shaft.

Anyone recognize what this hole was for? It's gonna have to be plugged up for a conventional carb swap.
 
I'll have to look when I get home. I think I understand what hole you're mentioning. In the view of your photo it looks like a dimple, on the side of the carb, inline with the throttle shaft with the spring. Tiny hole like 1/16 size or so. I'll check mine out when I get home.
 
Reply to Hotshot:

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Examined a Tilly HS9A that I have laying loose and the hole in bottom right is a blind hole, function unknown. Top right hole is for the implulse passage to operate fuel pump. 'Dimple' bottom left is also blind and of unknown function.

On some Walbro SDC the hole on bottom right leads to an accelerator pump if equiped. Mostly some Homelite XL-101 types.
 
Wrong Hole?

I think the hole he's asking about is the real small diameter one on the side of the carb, adjacent to the throttle shaft. You can only see it tangentially in his photo. I'm not sure though, maybe if Hotshot would put a pipe cleaner in it or something we could be certain which hole we're investigating.
 
I'll have to look when I get home. I think I understand what hole you're mentioning. In the view of your photo it looks like a dimple, on the side of the carb, inline with the throttle shaft with the spring. Tiny hole like 1/16 size or so. I'll check mine out when I get home.

Opihi59 & 67L36Driver,

Yes, that's it on the right carb side, just to the left of the throttle spring. It looks like a shadow
in the picture. It measured less than 0.085" diameter & I plugged with a piece of lead shot & JB weld.

Thanks for the input guys, had never seen that before on a HS series carb.
 
Okay, third time now since Photobucket (insert long foul sting of your favorite expletives here) has crashed my 'puter each time so far in trying to post these (insert additional long foul sting of your favorite expletives here)

Hole in question, with pipe cleaner thru it:

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I think this represents a hole to allow a minimum required amt of air thru for initial combustion while the choke is fully closed. Sort of akin to that little hole thru the base of your automobile thermostat that lets just a bit of water thru if the open/close mechanism is frozen up. Not going to pontificate more for if this doesn't post this time my puter goes into the pond.
 
I think this represents a hole to allow a minimum required amt of air thru for initial combustion while the choke is fully closed. Sort of akin to that little hole thru the base of your automobile thermostat that lets just a bit of water thru if the open/close mechanism is frozen up. Not going to pontificate more for if this doesn't post this time my puter goes into the pond.

I'll vote for that......................................................................
 
Bars

I have had a few questions about bars for this Roper. The original mount seems no longer to be available, but the oiler will still lube the chain with D176 bar which seems also hard to find. You can get a lot more versatility by going from a .325 bar/chain to a 3/8 bar/chain which is way more available now than the .325 setup. By fiddling with my sprocket from my Husqvarna which is 3/8 I found serendipitously that it will sleeve directly on the drive for my Ropers. I bought an Oregon part number 18720 sprocket, 7 spline 3/8 which looks like this:

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And used this bar

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And have another of my running Ropers ready to throw chips. I am sure that this process is well known to the forum, but for me, it was an independent discovery I figured I'd share. I wanted an 18" bar/chain combo, but this was just what I found first. I am sure the 3.7 will pull it though without a problem. Yes the filter/cover is off this saw as well as the bracket that holds the cover down, but I have been fiddling with the carb on this one and am swapping to a different carb soon.
 
My one and only Craftsman/Roper came with a rim dive drum from the get go. Tossed the .325 and installed the .375 as I had several 'Mac' bars at the time. He has no problem pulling a 20" bar.


I have to re-visit mine and put the compression release back in so I can pull him over. Thought I was making an 'improvement' at the time.:rolleyes2:
 
I'm tempted by these old Craftsman/Ropers - my Dad had one when I was a teenager (one of the later, more styled ones), and I used it a fair amount. I recall it being a darn good saw!
 
Likely the one you're referring to that your Dad had is featured in some of my photos a few entries up. I prefer the Roper primarily featured in this thread, but they are all good saws. They are readily available on ebay, as well as parts units and I have accumulated a number of them. In this thread I have listed substitute part numbers for things like the crank seals, rings etc.
These are by no means pro-saws, but they are excellent and rugged utility saws, very durable, functional and mechanically very simple. The only thing I would suggest doing is to remove any and all parts associated with the "power sharp" device.

And yes, there are a ton of them on ebay right now.
 
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