Chainsaw Rebuilder?
- Thread starter Bodean
- Start date
- Replies 101
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woodworkingboy
TreeHouser
Deva, I don't recall if you mentioned having rebuilt a carb before, but if you haven't, be mindful that the metering side diaphragm (4 screws holding on the top cover plate) sits on top of the gasket. The opposite side pump diaphragm is reversed, it sits against the carb body under the gasket.
woodworkingboy
TreeHouser
Very straight forward it is. The only thing that I guess could be said that is delicate, is if you want to disassemble the whole carb for cleaning. Two things.... On the pump side is a little screen that sits in a recess, about 3/8" in diameter or so. You can pop that out with a pointed thing like an ice pick. It can have dirt in there. If you shoot air at it, it can fly out to who knows where. On the opposite metering side, when removing the screw that holds the little pin that holds the metering lever that raises the metering needle up and down with the diaphragm pulsations, there is a tiny spring that sits in a little recess beneath the lever. You need to be mindful that it doesn't fly out and disappear when you take out the screw holding the horizontal pin. Keep you finger on the metering lever for control when removing the screw, then carefully taking finger pressure off the lever will allow it to be lifted away and the spring is sitting there accessible. It probably fell over. Taking the screw out, then releasing the pin and taking out the spring and metering lever, then allows you to lift out the metering needle if it has slipped off the end of the lever. If you bought the whole rebuild kit and not just the diaphragms with gaskets, there will be a new metering lever and needle with it. Metering levers don't normally get buggered up unless they've been tweaked, but it's good to replace the needle. The metering lever should sit flush with the surface of the carb body around it or a slightly raised ridge (flat or ridge depends on carb model) when everything is assembled, or else it needs to get bent to be like that. There must be videos and stuff on the net that clearly explains that if in doubt. It's all very simple really, but trying to describe it may make it not seem that way.
Putting the spring back in and having it match up beneath the lever like it should be can be a little fiddle. I like to set the spring in its little recess standing up, then after putting the pin through the lever and hooking the needle on the end, drop the affair down in place without the spring tipping over. The horizontal pin has to fit into it's groove and the screw put in over that holds it all in place. Pretty self explanatory really when you see it.
Putting the spring back in and having it match up beneath the lever like it should be can be a little fiddle. I like to set the spring in its little recess standing up, then after putting the pin through the lever and hooking the needle on the end, drop the affair down in place without the spring tipping over. The horizontal pin has to fit into it's groove and the screw put in over that holds it all in place. Pretty self explanatory really when you see it.
woodworkingboy
TreeHouser
Oh yeah, the only things that you can take out to facilitate cleaning after that are the high and low speed adjusting screws. I shoot carb cleaner into the holes. When you do put the screws back in, don't seat them too tight is what gets said, not to damage the fine tips.
pigwot
M's, Juniper's, Lowen’s, and Inge’s Grandpa
Deva, I've had a few that ran (huh, didn't run that is) like that and it was a tiny tear in the diaphragm. Second vote for rebuild that carb.
Jay, I have spent my share of time looking for those tiny screens and springs
Jay, I have spent my share of time looking for those tiny screens and springs
Cobleskill
Treehouser
Those little springs can test your patience if you are not in the mood for small work.
Bodean
Cali dreamer
- Thread Starter Thread Starter
- #37
Nice Steve.
I just took the carb out of my 44 for the first time. Wow. Pretty easy. I was worried I was gonna break the tab on the trigger where the throttle linkage ties in.
I changed the fuel line and blew out the fuel filter and it definitely idles better. Might have saved a carb rebuild but I gotta try more tomorrow with less beer to make sure the saw works.
I just took the carb out of my 44 for the first time. Wow. Pretty easy. I was worried I was gonna break the tab on the trigger where the throttle linkage ties in.
I changed the fuel line and blew out the fuel filter and it definitely idles better. Might have saved a carb rebuild but I gotta try more tomorrow with less beer to make sure the saw works.
Bodean
Cali dreamer
- Thread Starter Thread Starter
- #38
Well. Actually didn't fix it.
Seems it runs longer now before it dies out. Might have stretched out the fuel line trying to get it to seat in the top of gas tank....I used my finger and stretched it out good.....hindsight some long needle nose pliers to hold the fuel line inside the tank...
It ran a little more past a choked pop into something I could throttle a couple times before it sputtered.
Seems it runs longer now before it dies out. Might have stretched out the fuel line trying to get it to seat in the top of gas tank....I used my finger and stretched it out good.....hindsight some long needle nose pliers to hold the fuel line inside the tank...
It ran a little more past a choked pop into something I could throttle a couple times before it sputtered.
woodworkingboy
TreeHouser
You didn't go to the trouble of pulling off the carb and then not check the diaphragms? That would be a capital offense. 
sawman
TreeHouser
That's my vote��
CurSedVoyce
California Hillbilly
Sheeshh...let the man practice.... 
SeanKroll
Treehouser
Blew out the fuel, or air, filter?
Bodean
Cali dreamer
- Thread Starter Thread Starter
- #43
Blew out the fuel filter and put in a new air filter.
Haha. I'm practicing.
Good one.
Jay. I was hoping I could get away with that. I'm a little chicken for the carb tear down, but I'm on it. Love this saw too much not to have it barfing noodles for me.
Haha. I'm practicing.
Good one.
Jay. I was hoping I could get away with that. I'm a little chicken for the carb tear down, but I'm on it. Love this saw too much not to have it barfing noodles for me.
Cthompson22
TreeHouser
- Joined
- Jul 5, 2015
- Messages
- 13
A carb tear down is no big deal just be sure the shop floor is cleaned up good. If parts go flying it may be a bit of a pain to find them, i speak from experience. I have had them totally apart many times Welch plugs out and all. Realistically for a basic carb kit installation there is not much you can mess up aside from the lever height on the needle. The new arm or even the old one may not be properly adjusted when reassembled. The rest is more or less just bolting on new parts except for some of the carbs like a 200t where a kit will not fix the known carb issues but that's a different story. You can usually look up the lever height and adjust it to where it needs to be. Just be sure you put the stuff back on right such as the diaphram and gasket, if they aren't in the right order they will not work correctly.
Pm me if you need help I have worked on a lot of them, I do all of my own mods and mechanic work when it comes to saws so I have been around them a bit. Not an expert but can figure most of it out.
Pm me if you need help I have worked on a lot of them, I do all of my own mods and mechanic work when it comes to saws so I have been around them a bit. Not an expert but can figure most of it out.
Al Smith
Mac Daddy
Some of the Zama c1Q carbs develop problems with the accelerator pumps .Although I've never done it they say you can block off the pump .I did have one that had some sealing issue around the welch plugs in the fuel chamber which I sealed with red Loctite and it seemed to work .
woodworkingboy
TreeHouser
Deva, was more joking than being critical of the trying to get away with the simplest fix. Been often guilty of that myself. The 4 screw cover side is the metering diaphragm, the side probably most prone to being the culprit. Easy to check both sides without taking anything that can get lost apart. Often throwing on some new ones if needed will solve the problem without going any further. Compared to the new ones in your rebuild kit, diaphragms in need of replacement will have lost their suppleness and flexibility.
Cthompson22
TreeHouser
- Joined
- Jul 5, 2015
- Messages
- 13
I have done a few with success. Its a simple fix and beats buying a new $70 carb once a year. I want to check into using the 025 carb. I was told it's the same as the 020t carb but is adjustable, might give it a go and see how it works it's a walbro not a Zama I believe.
woodworkingboy
TreeHouser
020 saws had both Walbro and Zama carbs, both adjustable, Walbros on the earlier models. I think you'd hard pressed to find a Walbro speced for that saw now.
Al Smith
Mac Daddy
I only speculate that problems can be traced right back to faulty seals more often than funky carbs .Before after market cylinders and pistons flea bay might have a dozen crankcases for 020 and 200T's for about 50 a pop .At the time using OEM parts it would be half the cost of a new saw .If you have some shop do the work it would nearly be the cost of a new one at the time .
