McCulloch Chain Saws

[dieselsmoke]

Big VS Little

Man what a difference in size, A mini mac 6, next to my 3-25. A very good friend asked me to look at this little saw, and see if I can get to run. So far I've only had to pull the motor out 2X. First to clean and inspect, Secondly my brain fart. Id rather be working on the 3-25, but am still waiting on a carby diaphragm, and the soaking of the fuel bowl.

 

[madrone]

no pic's bud. if you need some part's let me know i've got some extra .

Huh? Pics are there for me. How bout now?

 

[paccity]

damn, that should be in the wtf thread. if your going to fix it let me know what you need.

 

[OldDeadWood]

Dirt!

There's a lot of talk about carburetors lately, so here's a tip that may help you, or you may already have your own system.

I like to pour the fuel out of my saws after using them so I don't have a bunch of saws sitting around full of fuel.

That's not the tip.

The tip is: I have a fairly large funnel that holds a Mr Coffey type filter. Every time I pour chainsaw fuel I pour it through a coffey filter. It doesn't stop the oil mix, but I does stop the small junk that could mess up you carb.

ODW

 

[cpr]

Vic - There should be a number stamped on the crankcase where the model number would normally be. I don't remember the block number for the Super 250, something like 83830 maybe?
Mark

FWIW, my 250 is stamped "250" on one side and SN on the other. My Super is a blank block and has the riveted tag in the corner of the airbox.

 

[HeRoze]

i don't know if acres has it correct or not, but they say the S-250 s/n has a prefix of 12 or A12


Super 250

 

[cpr]

Yes, SN Prefix is 12. Model # is 600100.

 

[HeRoze]

stamped 250 ---- 25921. none of the three IPLs show a 25 prefix. carb is interesting, though. none of the 250 IPLs show the primer FB, with a shroud over the intake side.

 

[RandyMac]

Does that 250 have the old fuel tank front with the un-drilled oil tank fittings?

 

[HeRoze]

Does that 250 have the old fuel tank front with the un-drilled oil tank fittings?

I don't know old from new, so.... If you are talking about something else (like the actual hose fittings) let me know what to look at, pls.

 

[heimannm]

Have a look inside the fuel tank to see if it is drilled and tapped for the automatic oil pump that would be installed there.

Mark

 

[HeRoze]

looking from the front of the saw, into the fuel tank, looking towards the oil tank. I don't see anything like the IPLs in terms of a pulse pump. What I do have is what appears to be a single 10-24 hex head going from the fuel to the oil tank, and a locating pin about 3/8" to the right of the hex head most likely coming the other way (oil to fuel tank). no extra tapped holes to be seen. tank is the cleanest I have ever peered into, though. brand new duck bill and pickup.

 

[HeRoze]

based on what I see so far, i'm thinking a regular 250. if I get a wild hair I'll measure the bore and stroke. can I accurately measure the bore from the exhaust port, using the rings for the short side and the far side wall of the cylinder for the long measurement?

 

[dieselsmoke]

Herose, here's the steps to get a bore measurement: pull the muffler and use your dial caliper to take two measurements, ex. port face to piston skirt and ex. port face to the far side cylinder wall. Subtract the small number ( first measurement ) from the big number and you will have the bore size. In your case you should get 2.125". The difference between 80cc and 87cc is in the stroke. 1.375 Vs 1.50". hope this helps. BTW I have a gearbox and a descent bar for your 2 man saw, if your interested send me a PM.

 

[Eccentric]

The number you see on the right side of the block underside (starting with 25) is not the saw SN. The MN and SN will be stamped on a small tag held down with one of the oil tank cover screws. It is often missing. You can get a "good enough" measurement of the bore using a popsicle stick. As Brad said, the stroke is the measurement you need to get here. Use a straw down the sparkplug hole. Measure at TDC abd BDC and subtract. 1.5" for 87cc and 1.375" for 80cc. That won't tell you WHICH 80cc or 87cc Mac you have though. You do have "250" on the block to help with that though...

My 'regular' 250 had a thin blockoff plate in the fuel tank in the place where a pulse driven auto oiler pump would be. Both that saw and my Super 250 had 600100 stamped as the MN on the little MN/SN tag. The 'regular' 250 tag has an 11 SN prefix IIRC, while the Super tag has a 12 SN prefix. My 250 block has "250" and a block # that matches a 250 crankcase # in the 250 IPL. My Super has the 'magic' 83830 Super 250 crankcase # (which isn't always on S-250 blocks) and little else . I'll post a pic of the 250 tag next to the S-250 tag this weekend along with a pic of the AO pump blockoff plate from the 250. Will also shoot some block stamping pics if I remember...

 

[HeRoze]

Thanks all.

Even though I'm more comfortable fixing Mac saws now with a couple under my belt, I've just started learning about them.
What is the # on the right on the block? roughly what size is the 'small' mn/sn tag? I haven't noticed it on any of my tear-downs.

dieselsmoke - I'll keep the 2-man stuff in mind, and thanks for letting me know. I think I'll end up with one saw pulling parts from the two, and there is one good B&C and hopefully good GB. If I end up with enough good parts for two, I'll be on the hunt.

 

[a. palmer jr.]

Thanks all.

Even though I'm more comfortable fixing Mac saws now with a couple under my belt, I've just started learning about them.
What is the # on the right on the block? roughly what size is the 'small' mn/sn tag? I haven't noticed it on any of my tear-downs.

dieselsmoke - I'll keep the 2-man stuff in mind, and thanks for letting me know. I think I'll end up with one saw pulling parts from the two, and there is one good B&C and hopefully good GB. If I end up with enough good parts for two, I'll be on the hunt.

When you get a hundred saws under your belt you'll still have a few that will give you fits!

 

[SawGarage]

Mornin' Gents....

been a while since I've parused the forum related to what ALL IS CAD for me... (where it started, where it leads to ETC... ) the orange saws just seem to fill the void, and 'pass the time' till the yellow-bug comes around (sometimes in flocks this time of year...

I have two saws that have been biting @ my ankles lately...

a Super 6-10, and a PM 700...

I could use a set of rings for both...


AND

I could use some help in finding where to go, who to ask/beg, and/or where to buy... OR suggestions... (IE: part out the 700 if it's not in near-new shape, etc..)

Input is welcome... for the help I may raffle off a 790 that's been parked under the bench.

 

[HeRoze]

1.375 stroke. 250 it is! no harm, no foul. a bit disappointing since the guy sold it as a S-250, but was priced at a regular 250.

 

[RandyMac]

I don't know old from new, so.... If you are talking about something else (like the actual hose fittings) let me know what to look at, pls.

this is what I was looking for

There are some very early 250s that carried over the old style tank front and had a Flatback.
They also had some more deluxe features not found on later 250s, like the round muffler and rubber handgrip.
I have seen 4 others, one is on the CSCF and I have seen one here as well, I have the other two.
The one in the photo came to me as NOS, but stripped of the entire driveside, airbox cover and starter.
It has more "beans" then my other 250s.

This is the other one.