McCulloch Mac 2-10

[MacAddict]

Hopefully we can pick up all the carbs be worth every cent on them if they are bullfrogs just saying. The diecast of the carb you can't find anywhere

 

[MacAddict]

The rubber duck bill valve came today time to try to get this thing to run.

 

[Macgary]

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.

View attachment 524409

Mark

Mark or someone with knowledge on these carbs, is there supposed to be an o ring in the hole directly below the red duck bill valve in the pic?

 

[MacAddict]

He means here on the carborator hope this picture helps.

 

[Macgary]

Hi all, so I found this pic in another thread, Mark had posted the pic, sure looks like a black o ring in there to me above the circled duck bill valve.

 

[Macgary]

Well all put back together, new fuel line, pump diaphram and gaskets, adjusted screws and jet to factory spec. Won't run at all now, poured a little fuel in the butterfly and nothing. So I'm pretty much stumped.

 

[astnmacgto]

Better start from square one, check spark and then make sure It didn't get flooded due to something wrong with the carb

 

[MacAddict]

Checked spark has spark has pop wants to go just seems not getting fuel now.

 

[Macgary]

Okay disassembled the carb again soaked in berrymans for an hour to make sure everything was clean, blew it out with compressed air and made all adjustments to factory spec. Popped when I tried to start, then nothing. Took plug out to make sure I was getting spark and it was. Plug didn't smell like I was getting fuel. Shot a squirt of starting fluid in it which usually gets other saws I've worked on to start for a few seconds and nothing. So I am pretty much stumped.

 

[astnmacgto]

Spark outside doesn't always mean spark under compression, are points and condenser new/working efficiently is coil gap set correctly and is plug new?

 

[Macgary]

We cleaned and set points. New spark plug. Don't know about condensor or how to check if it's good or not. Don't even know how to set coil gap. Any help appreciated.

 

[astnmacgto]

I usually use a normal thickness, not a paper thin, business card, roll the flywheel over to where the magnets are at the coil stick the business card in between the two and loosen up the coil, the magnet will pull the coil to it and then you can tighten down the coil and pull out the business card, the gap should be .012 to .018 thick which is about what a business card is.

 

[astnmacgto]

Usually the signs of a condenser going bad is erratic or stumbling idle, or super weak spark, if I have points/condenser trouble I will almost always use an ignition module or bug to eliminate them, your local parts store should be able to get ahold of one

 

[Macgary]

Set the coil gap and still won't start.

 

[astnmacgto]

Did your spark change in color any, perhaps go from a faint or orange color to bright blue, you said even with supplemental fuel directly in the cylinder it still wouldn't fire?
ADLM

 

[Macgary]

Spark plug basically looks new like it just came out of the box. I'm going to double check #.

 

[MacAddict]

Okay so best way for me to explain what happens when I try and start it for one it does this weird thing with the recoil where it sounds like its stripping. Anyways sometimes it will connect and will pull anyways from step 1. What I do is prim 3-4 times no gas leak good, pull nothing, pull nothing, pull nothing, almost like it lost half its compression then after a couple pulls it starts to get compression again and will pop and fire for maybe 2 3 seconds then dies almost sounds like its getting gas to carb but not producing it to the engine i don't know how this works but I'm so fed up with this saw about to just part it out and sell it, but before we do that I really think there's something going on with the pull start and its like stripping ill try and get a video of it.

 

[astnmacgto]

Take clutch cover off, make sure both starter pawls are on the bracket attached to the clutch as well as both springs, take a compression test.
ADLM

 

[MacAddict]

It has compression haha trust me just sounds like its stripping off the spring or something.

 

[astnmacgto]

Check the starter pawls that are on the clutch and make sure both springs are there