020T Rebuild - Initial Planning and Questions

[Zombiechopper]

Well, I've started on my first real full tear down and rebuild. This is a well used 020T from a tree service. I have a few questions off the get go as I have not ever had a saw this far apart. So far it is completely disassembled but the cases are not split

1) How do I check for bearing play? By trying to wiggle in any direction I can? How much play in the rod bearing is too much? I think the main bearings are tight and smooth as far as I can tell. The rod bearing has a fair bit of play and shows some wear but it doesn't seem any more than other newer saws I've had apart. I just don't know how one decides if that bearing is done or not because its a sloppy sort of wiggly thing

2) Main seals. How does one go about prying them out without damaging anything? When replacing them, how far in do you tap them? I have heard a few warnings about not putting them in too far but I don't really know how far that is. There seems to be three raised tabs on the case around the seals. Put them in flush with the tabs?

3) Accelerator pump epoxy fix. This saw exhibits the classic 200T bad carb symptoms. I have read somewhere that there is a way to fill the accelerator pump with epoxy or something like that. Was it pgg maybe? Any of this ring a bell? I am willing to buy a new carb if I have to but i want to try this first if anyone knows how.

4) Replacing leads on a coil. I found some bad or questionable wires on this saw. Can I replace all the leads off the coil or is it better to just get a better coil? ipl does show separate parts for each wire but I never hear about anyone re-wiring a saw so maybe its just easier to buy a better coil?

5) Porting. I am going to go as wide as I can on intake and exhaust but not raise or lower. How far to the edge of the skirt should I go? If I leave 1mm is that safe? Also, what if anything can I do with the open transfers? I can't really see anything to do to them

6) Squish. My initial plan was to send this saw to Will for a popup and decked cylinder but it seems to have a totally flat roof combustion chamber. There is only a tiny little spot for the plug head to go - only the tip of my finger fits in there. So, I can just lower the jug with sandpaper on a glass slab. I just don't know how tight to go on squish with a flat roof. I don't want to end up with a little detonation bomb. Just looking for a best guess on squish for a flat roof chamber. If I go too tight I can just add a gasket too so not a huge deal.

I know its a friggin novel. I appreciate any input guys. I will do a work in progress pic thread when I get parts together and get goin

 

[parrisw]

Hey good luck with it. As for the seals, I look to see where they are before I take them out, and just put them back to where they were. About doing the piston and cylinder, I think mine, there wasn't allot of room for a big popup, like you say its a small chamber, so the popup isn't very wide, but machining just allows the proper squish to be set. Yes you can rewire the saw if any leads are bad, just replace the wires, no need to replace the coil. I don't know about plugging off the pump circuit though? I'd like to know how to fix those carbs if it could be done, I have a bunch of bad ones. As for porting there isn't much room on these saws, but you can go a little wider, usually .100thou I think is a good safe margin.

 

[woodchuck361]

I'm guessing this saw is the one that looks like the ms200t and not the older 020av. Keep us posted, got any pics yet?

 

[lone wolf]

Well, I've started on my first real full tear down and rebuild. This is a well used 020T from a tree service. I have a few questions off the get go as I have not ever had a saw this far apart. So far it is completely disassembled but the cases are not split

1) How do I check for bearing play? By trying to wiggle in any direction I can? How much play in the rod bearing is too much? I think the main bearings are tight and smooth as far as I can tell. The rod bearing has a fair bit of play and shows some wear but it doesn't seem any more than other newer saws I've had apart. I just don't know how one decides if that bearing is done or not because its a sloppy sort of wiggly thing

2) Main seals. How does one go about prying them out without damaging anything? When replacing them, how far in do you tap them? I have heard a few warnings about not putting them in too far but I don't really know how far that is. There seems to be three raised tabs on the case around the seals. Put them in flush with the tabs?

3) Accelerator pump epoxy fix. This saw exhibits the classic 200T bad carb symptoms. I have read somewhere that there is a way to fill the accelerator pump with epoxy or something like that. Was it pgg maybe? Any of this ring a bell? I am willing to buy a new carb if I have to but i want to try this first if anyone knows how.

4) Replacing leads on a coil. I found some bad or questionable wires on this saw. Can I replace all the leads off the coil or is it better to just get a better coil? ipl does show separate parts for each wire but I never hear about anyone re-wiring a saw so maybe its just easier to buy a better coil?

5) Porting. I am going to go as wide as I can on intake and exhaust but not raise or lower. How far to the edge of the skirt should I go? If I leave 1mm is that safe? Also, what if anything can I do with the open transfers? I can't really see anything to do to them

6) Squish. My initial plan was to send this saw to Will for a popup and decked cylinder but it seems to have a totally flat roof combustion chamber. There is only a tiny little spot for the plug head to go - only the tip of my finger fits in there. So, I can just lower the jug with sandpaper on a glass slab. I just don't know how tight to go on squish with a flat roof. I don't want to end up with a little detonation bomb. Just looking for a best guess on squish for a flat roof chamber. If I go too tight I can just add a gasket too so not a huge deal.

I know its a friggin novel. I appreciate any input guys. I will do a work in progress pic thread when I get parts together and get goin

1)Rod is checked up and down only side to side don't matter don't let the side to side fool you when checking the up and down hold it straight as possible and no up and down should be perceptible.
2)Main seals take a close up with a digital camera or make notes as to which way they go in and notice how far in prob flush with the cases.To knock them out tap it in and then pull it out with a hook when it is on an angle
3)Buy a new carb you will save tons of time and aggravation.
4)Coil leads the high power wire screws on to the coil and can be replaced. so can the other wires be replaced.
5)Cant help you with that one but it will run great stock leave it alone.
6)Squish do away with gasket and If I remember 20 thou will work but double check as it has been a while.

 

[pgg]

Split the engine and the seals pop out easily enough, it's putting in the new ones that's the tricky part, they're a tight fit and made of bakelite which is brittle as f**k. Gotta be very patient and careful to get them started in the tight recess without breaking them, I've used a flat block of wood and hammer to try and tap them in as level as possible, and just tap them in to the same depth as the originals.

Brand new carb is the easiest, but you can whip out the throttle shaft to access the accel-pump and decide what to do with it, either replace the tiny O-ring on the tiny piston or just ditch the piston and spring and epoxy the stupid accel-pump hole shut. On the accel-pump Zama there's a welch plug at the back of the carb that accesses the accel-pump circuit, lets you plug the pump circuit without having to remove throttle shaft, pump and spring. The accel-pump passage runs thru to the main nozzle and if the pump is dodgy and not sealing, air gets sucked direct to the main nozzle and leans the fuel supply all to hell

 

[Zombiechopper]

Thanks Gents. That helps a bunch. Gotta sit down and do a parts order and buy some burrs for the dremel. I'll start a new thread when I start the work. I never have any time between work and the kids so it will probably a long drawn out process.

Everything I have ever read says to just buy a new carb and be done with it so I think I will just do that. Worst case is I'll have a spare for my other 200's

The port job is going to be fairly mild, which is all it can be but I have to do it if I'm in this far! Plus, I don't have much $ into this saw so it is a learning process for me before I do any of my other saws.

 

[Zombiechopper]

Split the engine and the seals pop out easily enough, it's putting in the new ones that's the tricky part, they're a tight fit and made of bakelite which is brittle as f**k. Gotta be very patient and careful to get them started in the tight recess without breaking them, I've used a flat block of wood and hammer to try and tap them in as level as possible, and just tap them in to the same depth as the originals.

Brand new carb is the easiest, but you can whip out the throttle shaft to access the accel-pump and decide what to do with it, either replace the tiny O-ring on the tiny piston or just ditch the piston and spring and epoxy the stupid accel-pump hole shut. On the accel-pump Zama there's a welch plug at the back of the carb that accesses the accel-pump circuit, lets you plug the pump circuit without having to remove throttle shaft, pump and spring. The accel-pump passage runs thru to the main nozzle and if the pump is dodgy and not sealing, air gets sucked direct to the main nozzle and leans the fuel supply all to hell

That is exactly what is happening. The guy I bought it from said it would idle erratic and figured it had an air leak somewhere but I couldn't find anything (I bet he couldn't either...) So I figured bad carb. I will probably try fix first


I still owe you some rep man. I appreciate sharing the top handle knowledge

 

[Zombiechopper]

I'm guessing this saw is the one that looks like the ms200t and not the older 020av. Keep us posted, got any pics yet?

same saw as a 200T but different cylinder, no flippy caps. Except mine has had half the parts replaced with 200T stuff so its a hybrid like the 044/440 bastards. I have yet to find a part that does not look exactly the same as a 200T. I thought the cylinder roof was different but maybe its just a little different timing?

 

[Zombiechopper]

One more thing - Hone the cylinder? It's getting new rings. I have a 3 stone cylinder hone. Never done it on a saw before. Compression was 150 before tear down

 

[jimbo1490]

same saw as a 200T but different cylinder, no flippy caps. Except mine has had half the parts replaced with 200T stuff so its a hybrid like the 044/440 bastards. I have yet to find a part that does not look exactly the same as a 200T. I thought the cylinder roof was different but maybe its just a little different timing?

The cases are different in their interface to the cylinder transfer ports. The interface relief is a few mm wider and slightly different in shape on the 200T compared to the 020T. The 200T has much wide ports which are divided vs the smaller single port of the 020T. If you mix up these parts, you should address this mis-match here to avoid potential flow reversal problems with the possibility of a 'flat spot' in the throttle response.

Jimbo

 

[MS260 Fan]

Split the engine and the seals pop out easily enough, it's putting in the new ones that's the tricky part, they're a tight fit and made of bakelite which is brittle as f**k. Gotta be very patient and careful to get them started in the tight recess without breaking them, I've used a flat block of wood and hammer to try and tap them in as level as possible, and just tap them in to the same depth as the originals.

Brand new carb is the easiest, but you can whip out the throttle shaft to access the accel-pump and decide what to do with it, either replace the tiny O-ring on the tiny piston or just ditch the piston and spring and epoxy the stupid accel-pump hole shut. On the accel-pump Zama there's a welch plug at the back of the carb that accesses the accel-pump circuit, lets you plug the pump circuit without having to remove throttle shaft, pump and spring. The accel-pump passage runs thru to the main nozzle and if the pump is dodgy and not sealing, air gets sucked direct to the main nozzle and leans the fuel supply all to hell

Don't want to hijack the thread but out of interest what is the correct carb for the 020T if Z-Chopper does buy one? When you buy a new one I assume they give you a different part number that has been upgraded? I have a newer Zama with Stihl p/n 1129 120 0650. It's replacing a Zama stamped C1Q. Neither works well on my project 020. I'm wondering if there's a carb newer than the 1129 120 0650 that works better with the 020t? I bought the saw as a project with 2 carbs so don't really know if either of the carbs are worthwhile rebuilding.

 

[pgg]

I wouldn't even bother honing those cylinders, new stihl rings bed in perfectly without it, dunno what the official carb numbers are 260fan, I use any suitable WT walbro non-accel carb and rig the throttle/choke shafts to fit the connections of the saw

 

[parrisw]

Hey this is turning out to be a really good 020 200t thread, it is much needed, this little saws can be bastards, but once you learn them, they are actually really easy to work on. I would really like to try to fix a carb for one, since they are so dang expensive here, last one I did cost $140, that's just stupid pricey!!

So once you remove the throttle shaft where abouts do you access the acell pump?

 

[Zombiechopper]

The cases are different in their interface to the cylinder transfer ports. The interface relief is a few mm wider and slightly different in shape on the 200T compared to the 020T. The 200T has much wide ports which are divided vs the smaller single port of the 020T. If you mix up these parts, you should address this mis-match here to avoid potential flow reversal problems with the possibility of a 'flat spot' in the throttle response.

Jimbo

my cylinder has divided transfers

 

[Zombiechopper]

 

[parrisw]

Looks the same as the 200's I've seen,

 

[Zombiechopper]

Looks the same as the 200's I've seen,

the transfers do not line up with the case opening. You can see the outline on the case top. Should I open up the ramp area to let those transfers flow to the corners? Or would a set of 200T cases be easier? Not sure if there is enough metal under there. I think this saw was caught on fire and dropped. The gas tank, recoil, cylinder are all 200T. The clutch cover/brake is cracked to hell. It is a definite franken saw

 

[parrisw]

the transfers do not line up with the case opening. You can see the outline on the case top. Should I open up the ramp area to let those transfers flow to the corners? Or would a set of 200T cases be easier? Not sure if there is enough metal under there. I think this saw was caught on fire and dropped. The gas tank, recoil, cylinder are all 200T. The clutch cover/brake is cracked to hell. It is a definite franken saw

Ahh, yes I see now. That's allot of material to remove. Sure a 200T case would be better. But it will probably run ok as is. I should grab my buddies old 020 parts saw and take a look at it.

 

[MCW]

Not meaning to hijack but are there any aftermarket 200T P&C kits available?

 

[Zombiechopper]

I don't mind hijacks one bit. The best info seems to come from taking the side roads...


No aftermarket P&C that I know of.