McC SP81E!!!!

[mad murdock]

I am stoked. Picked up an SP81E Saturday from the local saw shop for 15 bucks. Stopped by on a whim to see if they had any old trade-ins in the bone pile, that's how I got the last for 10-10's for abt 15 a piece from the same shop about a year ago. The AV mounts are all solid, innards are clean, has fire but low comp(50).  Cyl wall and top of piston look good through plug hole. Maybe will limber up with a little rust reaper I. The cyl? Going to give that a go before I break it down further.  8). I am a happy camper! My first big(ger) McCulloch!! 8)

[Al_Smith]

Tell ya what if you drown that thing with some good penerating oil like that Blue Creeper stuff ,Kroil or whatever you might get that thing limbered up .

I did that on a Mac 700 that would barely turn over when a guy found it a transfer station with the recoil missing and that old saw does very well now . I never tore the engine down ,just put on a recoil  from a junk 700 I had .

If that thing comes back up to full compression it will be tough to turn over without the use of the decomp which you might check to see if it's clear .Those poppit type have a tendency to not seal well after they've sat a while unused .

FWIW the SP 81 was made before McCulloch had problems towards the end with their plating process so with luck  the plating is still intact .

Pull the plug and drown that thing for about a week before you even try to start it .You have to make certain those piston bearing are free .If they aren't they will come apart like dollar watch and needle the cylinder .

[mad murdock]

Thanks for the tips Al,  It isn't seized, I checked the comp by pulling the thing through, showing about 50PSI  now.  I am thinking that throwing the penetrant in, it may free up the rings,and if that is the issue, the compression will come up near spec, or at least in the 140-150 range, otherwise, I will take it apart to see firsthand how it all looks, and fix accordingly.  Question for you, It has a Tillotson carb, is there a preference as to which is better, that or a Walbro? or are they equally suited?

[Al_Smith]

On carbs I never found a whole lot of difference in them nor the Zama used on the 805 and 850 .

Now on those rings if the cylinder is smooth most likely they are just a little stiff .The things are thin rings made of tool steel which should last almost  forever .

Once you soak it down real good for a couple days ,week if it pulls over smoothly it's probabley okay .But if you feel it hanging it could be cutting plating which will hang the rings .

If in the unfortunate event that happens remove the bottom handle so you can peel the muffler off and get a peek inside .If it is carving plating tear it down before you  wreck it starting it .

Generally speaking there is a reason a saw gets tossed in a dealers dead pile .You gotta figure out why .