I'm macgarys son this was our project together and here's a picture of the throttle pin and when I press primer button it pours gas from this black hole idk if this is supposed to be a rubber gasket or plastic or what but I know it's not supposed to have any gas coming out of the carb. Please let me know if this is plastic like how it feels or was once rubber. Also picture I'm pulling on the trigger just to show the black plastic (or once rubber) seal.
McCulloch Mac 2-10
- Thread starter Macgary
- Start date
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You will have to determine if you have the single needle or double needle version then look through the attached instructions.
Mark
Mark
Sorry about the photos, but that is the best electronic copy I have. Put up some photos of yours and we can try and determine which you have. If the H adjust screw is a stop for the throttle at wide open you have the single needle type, if the H adjust screw goes into the body of the carburetor it is the double needle type.
Mark
Mark
That is the single needle, note how the Hi Mix screw controls the position of the throttle at wide open.
Mark
Mark
There is no seal in that hole, it is supposed to allow air in to help atomize the fuel before it passed through the venture. It looks to me like either the fuel delivery tube (7) is blocked or you have a lot of wear in the fuel seat that the needle passes through. McCulloch did supply both the air orifice and the fuel orifice as replacement parts, but I have no idea how you would ever manage to pull the fuel orifice out being so small and so deep in that bore.
Mark
Mark
Check the tube first to make sure it is clear, don't assume the carburetor is bad.
Mark
Mark
Wrong tube. You need to make sure the tube that delivers the fuel/air mix to the venture is clear all the way. Remove the carburetor and look up from the bottom, you will see it sticking down in the opening. If that tube is blocked then fuel cannot pass to the engine, and will be forced out the air bleed orifice as you have pointed out.
Mark
Mark
Okay I see and now that I know what your saying I'll just take apart the carb again and take pictures and post them a little later or tomorrow when I can get around to doing it. Thanks for all the help so far mark
Ok, got home from work this morning and we set all 3 adjustment screws to spec from the pdf manual Mark supplied, thanks once again Mark for all your help. Never had to adjust a carb quite like that before. Another interesting fact I found out is that this is a walbro carb special made for mcculloch back in the day. Anyway I believe it was out of adjustment pretty bad. Will have to wait till later to try and start cause I don't want to upset my neighbors with this thing early on a Saturday morning. Oh, by the way it's not leaking anymore. Will keep you posted and may do a video if we get her going.
astnmacgto
Carnac The Magnificent
Your neighbors need to learn to appreciate the finer things in life, like the sound of a 2 stroke in the morning haha, in all seriousness, mark is a super guy, and super smart to boot
ADLM
Ok folks, well after making the carb adustment according to factory spec the saw wants to run popping and will run for a few seconds sometimes. It wants to run but won't. So when we took the carb apart the diaphram/ accelerator pump gasket was pretty much as hard as cardboard. My only experience with rebuilding carbs is on older cars where your diaphram was made of rubber. With this the diaphram is in a 3 piece setup, gasket, screen type gasket, and diaphram in a black gasket, sorry best I can explain. Anyway I guess my question is should that black gasket with the diaphram be hard and stiff including the accelerator pump diaphram? I'm thinking this is just toast all dried up and not working any more advice greatly appreciated.
astnmacgto
Carnac The Magnificent
The diaphragm should be very pliable, I would liken it to a thick Teflon tape kind of feeling, if the diaphragm is stiff or crinkly when you move it its junk
So that's what I was thinking and at this point I believe it t be the problem. So a guy has this gasket set for sale on ebay for like $25, yes asking a lot but he's the only one I've found that has these parts. I think I'll just get it, probably not worth it but it may be compared to trying to find an old 10-10 gas tank and carb to convert. At least this way it will be all original. I'm not giving up now, on a mission to get her going.
astnmacgto
Carnac The Magnificent
The way I feel about it, if you can keep it all original, that's the best way, I have been doing some work on mine and I think I'm getting pretty close, if everything works like it appears it will, I'll be able to switch between the two different carbs in a matter of about 30 mins, I dont think I will ever take off the sdc but it will be nice to not have demolished everything about the saw that makes it what it is
ADLM
