McCulloch Chain Saws

[edju1958]

Hi Guys,I've got a 610 that's driving me crazy.I bought it last week off Feebay & got it for a decent price - $77.Supposedly it was "refurbished",I gues that what they call a saw with a rebuilt carb on it.Anyway,I got the saw & put fuel in it & I pulled pulled.I couldn't get it to fire for nothing.Finally I primed the carb & it finally gave a few puffs & then finally it took off,but as soon as the fuel was gone that I'd put in it it died.I decided to pull the carb & have a look - see.The carb was freshly rebuilt & was as clean as a whistle,so I decided to put it back on & that's when I discoveredc that the base mounting gasket was torn & should've never been put on the saw.I replaced the gasket & put the carb back on the saw,only now it won't fire unless pull the plug out & squirt gas in the plug hole.I changed the fuel filter as well.Does anyone have any ideas as to what's going on with this saw & why it won't draw fuel?Thanks in advance.
Ed

 

[BigBlue]

Hi Guys,I've got a 610 that's driving me crazy.I bought it last week off Feebay & got it for a decent price - $77.Supposedly it was "refurbished",I gues that what they call a saw with a rebuilt carb on it.Anyway,I got the saw & put fuel in it & I pulled pulled.I couldn't get it to fire for nothing.Finally I primed the carb & it finally gave a few puffs & then finally it took off,but as soon as the fuel was gone that I'd put in it it died.I decided to pull the carb & have a look - see.The carb was freshly rebuilt & was as clean as a whistle,so I decided to put it back on & that's when I discoveredc that the base mounting gasket was torn & should've never been put on the saw.I replaced the gasket & put the carb back on the saw,only now it won't fire unless pull the plug out & squirt gas in the plug hole.I changed the fuel filter as well.Does anyone have any ideas as to what's going on with this saw & why it won't draw fuel?Thanks in advance.
Ed

Could be several possibilities. Fuel filter on pick-up line plugged up (I'm assuming a 610 has something like the 10-series and other older Macs). Fuel line has a crack in it so the carb can't get enough vacuum to pull fuel. Carb rebuilt with something amiss inside. Gas tank cap vent plugged?

Rob

 

[fossil]

Hi Guys,I've got a 610 that's driving me crazy.I bought it last week off Feebay & got it for a decent price - $77.Supposedly it was "refurbished",I gues that what they call a saw with a rebuilt carb on it.Anyway,I got the saw & put fuel in it & I pulled pulled.I couldn't get it to fire for nothing.Finally I primed the carb & it finally gave a few puffs & then finally it took off,but as soon as the fuel was gone that I'd put in it it died.I decided to pull the carb & have a look - see.The carb was freshly rebuilt & was as clean as a whistle,so I decided to put it back on & that's when I discoveredc that the base mounting gasket was torn & should've never been put on the saw.I replaced the gasket & put the carb back on the saw,only now it won't fire unless pull the plug out & squirt gas in the plug hole.I changed the fuel filter as well.Does anyone have any ideas as to what's going on with this saw & why it won't draw fuel?Thanks in advance.
Ed

How's the compression Ed?

 

[edju1958]

I didn't take a reading,but it seems to have plenty.It'll run with a prime in the plug hole.I'll see if I can get my son to do a compression test for me on Sat.Supposedly the guy who sold it on Feebay said he had it running from a cold start & shut it off & started it again hot,but people have been known to lie through their teeth too.It's awful funny that I can't get it started period.I do know how to start a Mac,I have a Timberbear which is basically the same saw,only 5 cc difference.

 

[toofuss]

Check the pulse port under the carb also.

Sent from my SM-G930R4 using Tapatalk

 

[fossil]

I didn't take a reading,but it seems to have plenty.It'll run with a prime in the plug hole.I'll see if I can get my son to do a compression test for me on Sat.Supposedly the guy who sold it on Feebay said he had it running from a cold start & shut it off & started it again hot,but people have been known to lie through their teeth too.It's awful funny that I can't get it started period.I do know how to start a Mac,I have a Timberbear which is basically the same saw,only 5 cc difference.

If it fires with a charge through the spark plug hole and not through the carb venturi it could mean a major air leak. The saw needs a good seal for the piston to provide crankcase pressure to push the fuel charge up the transfers.

 

[Beetlejuice]

If it fires with a charge through the spark plug hole and not through the carb venturi it could mean a major air leak. The saw needs a good seal for the piston to provide crankcase pressure to push the fuel charge up the transfers.

Could it be a reed valve stuck?

 

[edju1958]

All of these things that have been suggested by everyone here will have to wait indefinitely,I'm having a long awaited hand surgery (2+ yrs.).Im not being an ass here,but as I said in my original post - I put a new fuel filter on it,so that can be ruled out.I'm thinking it's got to be something simple,what can happen to a saw in transit that'd cause this?I'm not that good at diagnosing these things.I've only been tearing into saws for a few months now.I'll try to change out the fuel line when I'm able as that's the easiest thing to do without taking the carb back off again.
Ed

 

[Beetlejuice]

All of these things that have been suggested by everyone here will have to wait indefinitely,I'm having a long awaited hand surgery (2+ yrs.).Im not being an ass here,but as I said in my original post - I put a new fuel filter on it,so that can be ruled out.I'm thinking it's got to be something simple,what can happen to a saw in transit that'd cause this?I'm not that good at diagnosing these things.I've only been tearing into saws for a few months now.I'll try to change out the fuel line when I'm able as that's the easiest thing to do without taking the carb back off again.
Ed

Hey Ed,, when's the doc gonna practice on your hand.? We on this MAC channel always push good vibes to anyone in need. In other words, "GOOD LUCK". I'm working on your care package.. Good things take a long time.. K

 

[fossil]

Could it be a reed valve stuck?

I'm pretty sure that series is piston ported.

 

[Beetlejuice]

I'm pretty sure that series is piston ported.

Tim, I think you're right.. Was a guess..

 

[heimannm]

Most likely the problem is in the carburetor, stuck needle or plugged port. Might also be the fuel pump diaphragm is stuck or otherwise fouled up.

Mark

 

[Brian Thacker]

Or even could be a bad crank seal. Not letting it pull a vacuum in the crankcase and not pulling fuel from the carb. Many possibilities.

Brian

 

[edju1958]

i had the surgery this a.m.i had a nerve block & i can only use my left hand to type.thanks for the good vibes! i didn't like the way the metering lever was working,it acted like it wasn't picking up the needle valve at all or enough.the problem with the kit was that they don't give a new metering lever.i can maybe get another carb from either ebay or chainsawr for a few bucks,rebuild it when i'm better and install it to see if there's any difference.when it comes to diagnosing carb problems i'm 50/50 at best.
ed

 

[Beetlejuice]

i had the surgery this a.m.i had a nerve block & i can only use my left hand to type.thanks for the good vibes! i didn't like the way the metering lever was working,it acted like it wasn't picking up the needle valve at all or enough.the problem with the kit was that they don't give a new metering lever.i can maybe get another carb from either ebay or chainsawr for a few bucks,rebuild it when i'm better and install it to see if there's any difference.when it comes to diagnosing carb problems i'm 50/50 at best.
ed

And missed it by just that much, SH*T the bed!!!

 

[Beetlejuice]

And missed it by just that much, SH*T the bed!!!

But I don't hit every one

 

[heimannm]

It is really not necessary to replace the metering lever, they can be adjusted easily enough. The only case where a change would be needed is if the diaphragm has the tit for a fork and the lever doesn't have a fork or vice versa. 600 Series McCulloch saws should have a Walbro HDB or less commonly Tillotson HK, either one is popular enough and there should be a lot of parts out there if you need something.

Mark

 

[Brian Thacker]

My 610 has a Zama C2 carb. I think it came with any of the 3, the Walbeo, the Tillotson and the Zama. If the needle is not opening then the saw is not going to get any fuel. When you get well you can look at the metering arm and see if it is adjusted properly and also look for the pulse line and see if it is clear and letting the pulse get to the carb. Also look at the spring under the arm. It could have somehow gotten dislodged during transit.

Brian

 

[BigBlue]

While reassembling my Pro Mac 800 after a new piston I am running into a couple issues remembering where parts go. I disassembled it last fall so things are a bit foggy. Could anyone tell me the following from this pic:

Where does the washer-shaped thing with metal inside and black plastic thicker outer ring go?
Do you recognize the black plastic disc with a hole in the center and a small peg on one side? This might not even be from the saw but it was in the mix of parts.
How about the screw with the bent metal washer (but not washer)?

The shoulder bolt I figured out was from the coil. The quarter is just for size reference.

Thanks,
Rob

 

[PogoInTheWoods]

Where does the washer-shaped thing with metal inside and black plastic thicker outer ring go?

Front frame mount hub. #29 & #30 in the IPL.

​

How about the screw with the bent metal washer (but not washer)?

Possibly the ground attachment between the a/v bracket and the tank -- #56 & #57. Could be a couple of other locations as well.

​

Do you recognize the black plastic disc with a hole in the center and a small peg on one side?

Don't recall that piece off hand. Somewhere in the chain brake assembly maybe but don't see it in the IPL. Maybe Mark can clarify it and offer a couple of other possibilities for that 1/4 - 20 hex screw with the lock tab as well.

​