Mac 10-10 ID help

[SpikeDmax]

I recently acquired an early 70's vintage McCulloch Mac 10-10a and it looks like the previous owner JB welded a spot on the case, can anyone help me identify what was there or what the spot is for?

I have a guess it's an oil pressure intake air valve but I have no idea.

Does anyone have a picture of what is there originally?

Thanks

 

[SpikeDmax]

bump

 

[Maintenance supervisor]

That is where a ball bearing is pressed into the magnesium body of the saw . Originally the factory cross drilled the oil port there and then sealed it with a ball bearing.
Maybe it started leaking? And the previous owner sealed it up with epoxy.

 

[SpikeDmax]

That is where a ball bearing is pressed into the magnesium body of the saw . Originally the factory cross drilled the oil port there and then sealed it with a ball bearing.
Maybe it started leaking? And the previous owner sealed it up with epoxy.

You sir are a savior and a saint. Thank you, it was driving me crazy not knowing. I’ll leave well enough alone and now try to figure out why the oil cap is leaking from the center…
Thanks again for the help.

 

[Maintenance supervisor]

You sir are a savior and a saint. Thank you, it was driving me crazy not knowing. I’ll leave well enough alone and now try to figure out why the oil cap is leaking from the center…
Thanks again for the help.

No problem, plenty of good folks have helped me .
Suppose to be a duckbill valve in the cap.
Might want to head over to the Official McCulloch thread.

 

[heimannm]

Some of the oil caps had a duckbill valve, some just had a piece of felt, some had nothing at all and would always weep a bit of oil. The earliest saws just had a hole in the top of the oil tank with a cotter pin inserted as a vent, they also leaked oil if the saw was turned on its left side. The oil cap on those was unvented.

Unvented cap, #61 is the cotter pin in the hole in the oil tank to reduce leakage, 1968.



Hole in the cap, unvented tank circa 1973.



Felt plug in the cap from 1971.



Duckbill vent in the oil cap 1976.




Mark

 

[SpikeDmax]

Some of the oil caps had a duckbill valve, some just had a piece of felt, some had nothing at all and would always weep a bit of oil. The earliest saws just had a hole in the top of the oil tank with a cotter pin inserted as a vent, they also leaked oil if the saw was turned on its left side. The oil cap on those was unvented.

Unvented cap, #61 is the cotter pin in the hole in the oil tank to reduce leakage, 1968.

View attachment 1047061

Hole in the cap, unvented tank circa 1973.

View attachment 1047062

Felt plug in the cap from 1971.

View attachment 1047063

Duckbill vent in the oil cap 1976.

View attachment 1047064


Mark

Thank you for the diagrams, very helpful.
I believe my saw is circa 1973. I’ll dive into it, looks like it’ll probably need a new duckbill valve. If I can figure out the leaking oil and gas caps the saw will be a near perfect 10/10.

 

[wstan101]

Some of the oil caps had a duckbill valve, some just had a piece of felt, some had nothing at all and would always weep a bit of oil. The earliest saws just had a hole in the top of the oil tank with a cotter pin inserted as a vent, they also leaked oil if the saw was turned on its left side. The oil cap on those was unvented.

Unvented cap, #61 is the cotter pin in the hole in the oil tank to reduce leakage, 1968.

View attachment 1047061

Hole in the cap, unvented tank circa 1973.

View attachment 1047062

Felt plug in the cap from 1971.

View attachment 1047063

Duckbill vent in the oil cap 1976.

View attachment 1047064


Mark

Some of the oil caps had a duckbill valve, some just had a piece of felt, some had nothing at all and would always weep a bit of oil. The earliest saws just had a hole in the top of the oil tank with a cotter pin inserted as a vent, they also leaked oil if the saw was turned on its left side. The oil cap on those was unvented.

Unvented cap, #61 is the cotter pin in the hole in the oil tank to reduce leakage, 1968.

View attachment 1047061

Hole in the cap, unvented tank circa 1973.

View attachment 1047062

Felt plug in the cap from 1971.

View attachment 1047063

Duckbill vent in the oil cap 1976.

View attachment 1047064


Mark

Sorry to jump in here

Some of the oil caps had a duckbill valve, some just had a piece of felt, some had nothing at all and would always weep a bit of oil. The earliest saws just had a hole in the top of the oil tank with a cotter pin inserted as a vent, they also leaked oil if the saw was turned on its left side. The oil cap on those was unvented.

Unvented cap, #61 is the cotter pin in the hole in the oil tank to reduce leakage, 1968.

View attachment 1047061

Hole in the cap, unvented tank circa 1973.

View attachment 1047062

Felt plug in the cap from 1971.

View attachment 1047063

Duckbill vent in the oil cap 1976.

View attachment 1047064


Mark

Hey Mark, just stumbled upon conversation from 2009 and wondered if you would know of a replacement duckbill for the 10-10 oil cap #55 86402.

 

[heimannm]

The one in the oil cap is pretty easy, the red Homelite or green Poulan duckbill valves will work.





Mark

 

[wstan101]

The one in the oil cap is pretty easy, the red Homelite or green Poulan duckbill valves will work.

View attachment 1123299

View attachment 1123306

Mark

Outstanding! Thank you so much.

 

[wstan101]

Hey Mark, would you know if a Mac 10-10A coil would work on a Mac 10-10? Thank you

 

[heimannm]

The points ignition coils on the 10 Series saws are all interchangeable. There may be some variation in the length and diameter of the spark plug lead as some early models used a 5mm lead and tucked it under the shroud, later models used a 7mm lead and routed it outside the shroud.

This is a 10-10 with the lead routed under the rear shroud.



These are 10-10A models with the lead routed outside the rear shroud.



Mark

 

[wstan101]

Once again you come thru. Thank you, you're the king!