Roper 3.7 tear down and rebuild

[Gumneck]

Posted this one in the Nik's Poulan thread that I picked up last week and thought I'd extend this Roper built thread a little more. Need to address the nonexistent fuel line/filter in the tank and open up the carb to see how that looks. It runs on prime. Other than the outside grime/dust, saw is very clean and intact. Rubber on the handle is in very good shape, rim sprocket and bar sprocket show very little wear. For what it's worth, I'll post pics along the way.

 

[Gumneck]

Before cleaning.

 

[Gumneck]

After cleaning...

 

[Gumneck]

First Roper saw I've collected that didn't have a ton of rust on the bar. In black script, on the right side close to saw body "Automatic Oiler", mid bar "3.7 /17" , and the tip sprocket "Friction Fighter". Never seen it before and thought I'd post and probably hard to make it out in the pics.

 

[Gumneck]

Got it separated tonight. Trying to remember if this brass nipple for the fuel line comes out in order to get the line in the tank. CRS is flaring up from the last Roper I put fuel line in. Anyway, gonna saw a long 5/16 socket to the right length as I think I can get the nipple off without pulling the motor....I think. Feel free to type a correction.
Done for the night.

 

[Huskybill]

Did roper make the sears craftsman 3.75 saw?

 

[Gumneck]

Did roper make the sears craftsman 3.75 saw?

I've only seen the Roper built for Sears 3.7. I have 2 other ones that have the manual oiler in Island Teal/White and Red/White colors. This one here just has a plug/hole where the manual oiler goes. I haven't pulled the plug out to see in the hole but curiosity is building.

 

[Gumneck]

Here's the other Roper Sears 3.7 that I'm aware. The red one in the back, best pic I have that I can find. I have 2 of these that run and cut well.
Seems I"ve seen the older style Roper in a 3.7A version.

 

[Gumneck]

Got the fuel barb/nipple out without removing motor. Gonna have to see if I got some fuel line to fit, definitely gonna take some luck,lube, and loquatiousness to get that line and fitting back in.

 

[Gumneck]

Well, I got a chance to work on the fuel line install without the tank being split. I dont think it can be done. I'm wondering if the black Echo fuel line would be a little softer/pliable maybe even smaller than the tygon line. Once the line is on the nipple fuel tank side trying to pull it back through the tank enough to be able to catch the brass threads is seemingly impossible. Started removing flywheel and clutch last night. Flywheel was a bear to get budged but it moved and only destroyed one nut.
The clutch wasn't moving with the cheapo grinder tool I've used dozens of times. I'll try the right size bolts in the vice trick and turn the saw tomorrow.

 

[Gumneck]

With flywheel off on to the clutch, another puller I made years ago I found but was just not quite gonna fit. The vice trick turning the saw did not work only bent some 3/16 solid rod scraps I had laying around. So need to make it more solid and add a third leg to it. Put a few mig boogers on some bar stock....crude but clutch off.

 

[Gumneck]

Thought I was home free....nope, those 4 screws holding the motor were blowin spit, snot, and 3 farts tight. I got 2 out popping blood vessels and seeing crooked worked on the last 2 for 15 minutes and remembered I have the tool that is specifically made for this job...CRS cripples me. A few hits on the impact driver and we're moving!!

 

[Gumneck]

All that just to get this brass fuel barb/nipple screwed back in with new fuel line. The fuel line on the barb tank side gets squeezed out and it was impossible to get my cut down socket I made on the fitting and get it started with the engine still in. With it out, I could trim the line a little and put enought straight on pressure to get threads to start with a long socket. Tank is gassed up to see if any leaks, so far no leaks, see what happens by morning. Never seen this roper badge and thought I'd post.

 

[s sidewall]

Did you use echo fuel line? That's what I used when I split mine. Didn't want to use tygon cause I didn't want to go through that again.

Steve from my moto g(7) play using Tapatalk

 

[Gumneck]

Did you use echo fuel line? That's what I used when I split mine. Didn't want to use tygon cause I didn't want to go through that again.

Steve from my moto g(7) play using Tapatalk

Hey Steve, no I used tygon, i believe its the real tygon and not the cheap version. I have a spool of echo saved on my ebay watch list that I just haven't pulled the trigger on. It sounds like on the site that the echo is the way to go. The tank does not leak(yet) from an overnight soaking in straight gas. Flushed it out a few times then sprayed the inside with carb spray quite heavily to get more stuff out, which it did and is now looking good. The tank wasn't bad to start with anyway. So I'm curious, when you say you split yours do you mean split the fuel tank? Was yours leaking?

 

[s sidewall]

The fuel tank was leaking near the rear handle. So I had to completely disassemble the saw and split tank to reseal. With it completely apart, lot easier to run my lines and clean up the saw also. I used Derco to seal up the tank.

Steve from my moto g(7) play using Tapatalk

 

[s sidewall]

With tank split, easier to run line. The bottom point was where tank was leaking.

Steve from my moto g(7) play using Tapatalk

 

[ColoradoViking69]

Hello friends, thanks for keeping this thread alive! It’s fun to see the projects. I just got my old Roper/Craftsman 3.7 up and running this year, just in time for firewood season. It’s the older style, model 917.353762. She’s a powerful little saw! Put a 28” Oregon bar on it to save my back, and I’ve been impressed.
The one thing that could use some help is the clutch (I believe); when the saw is idling it tends to start spinning the chain. I haven’t really messed with the tuning, so I suppose that could possibly have something to do with it, but my guess is the clutch spring is worn out. Anyone happen to have one they could let go? I’ve only found one on eBay, and the guy wants $45 for it plus the freight… kinda steep I think. I’ve also contemplated making my own spring from some coil spring of the same diameter, since it’s just one loop on each side of the clutch. Whatcha guys think? Would it be worth taking apart, jimmy-rigging two springs, and trying to rivet the clutch back together? I’d much rather buy one from somebody’s parts saw, if y’all have a spare.

Sent from my iPhone using Tapatalk

 

[Gumneck]

Pull your clutch cover off and post a good pic. I would be inclined to idle it back a bit first.

 

[Gumneck]

I finally got the final touches done to mine tonight with both sides of the carb new diaphragm, new nylon nut on the flywheel and fuel filter I had laying around. I have other Roper 3.7's but this one is tight. Started easily and idled perfect right away. Low side adj only carb with 1.5 turns out. Worked on the chain and will put it to the real test tomorrow.
Side note for anyone redoing one of these. I must have moved the top oil line when viewed from the flywheel side enough that the backside of the flywheel was making contact with the ss line. I didn't notice until I was trying to pull the starter. I could here some scratching going on and initially thought a ring had got caught and was doing damage to the cylinder. Luckily, caught it before it rubbed a hole in the oil line. So just make sure the oil line is well behind the flywheel. I kind of like the idea of a longer bar on this one like Colorado's up above, that looks pretty good...I've got a 24" Husq bar I found in the street gutter to a 7/11 that I might just do if the mount works. I'm going to at least go ahead and polish the bar since you can't see any writing on it.