Mac super pro saws

[heviarti]

So i got an SP105 today. She's missing some parts and has some problems. So far I see that I need a new fuel line, a new vacuum line, a complete flywheel/recoil cover, A muffler and cover, an airfilter and cover, and maybe something else i don't realize yet.

There was a mechanical obstacle keeping it from turning a full revolution. My uncle thought it had a broken rod. Rather it had a lockwasher impacted in the center bottom intake port. It left a dent, and i have to go in and see how bad it is, I may be able to file (yes, i said file...) stone and then hone it and possibly have it run, because I don't think it affects the combustion chamber. if the piston and rings are good, i should be ready to go, If not I need to know if there is an overbore kit for them.

This is the second big mac i've seen with a lockwasher in the cylinder, which brings up the question... where are they coming from???

I can post pics of the saw..

Looking forward to outperforming an 046 and an 064 stihl

 

[heviarti]

here are some pics... first, the whole thing..

 

[heviarti]

the top...

 

[heviarti]

PTO side..

 

[heviarti]

and here's my little ding.. Amazingly it has decent compression.

 

[Mange]

This will be interesting to know about.
Nice saw.

Mange

 

[Bills Oak]

I have also seen this on the larger saws & I have concluded that the lock washers come from the muffler bolts. I have taken a muffler off more than once to check a cylinder & dropped the lock washer into the cylinder , & if for some reason I did not complete retrieving it with a magnet or whatever before refastening the muffler & got away from it for awhile I might forget about it being in there--seems like the problem is just plain stupidity or laziness!--You should be able to clean it up & get it running OK--does not look that bad..Bill Irvine

 

[heviarti]

Does anyone know what kart engine this is equal to?

 

[ozflea]

First the PM105 i believe is 100cc but does not have the removalable head like the Kart Engines and was a saw that lasted because it wasn't overstressed or working to hard.
The damage to the cylinder port may interfer with the port timing and the saw may not run as that seems to be the place where the washer done the damage, you can only try and see what happens.
How long is the cutter bar on your PM105 and it's a roller nose bar am i right ?

Bob Cornwell............Australia

 

[heviarti]

yeah, rollernose. from the lonest dog to the tip it measures 27 inches. I am a tad worried about the ding, but i won't know for sure until i can get a recoil assembly. I hate to drill one of the ones for my other saws, but i may have to.

THese are supposed to be quite the working saw when they are in good shape. I need this saw to work, because i'm tired of my boss giving me hell over my macs all the time. I figure if i humiliate the 064, i should do allright. that's his biggest stihl.. then all i have to do is find a 125, and outperform the 3120xp.

 

[Al Smith]

The Sp 105,is 106.5 cc ,or 6.5 cu in.I am not sure,but an sp 125 piston,may work,with a rebore .The sp 105 ,is 2.25 in. bore.The sp 125,is 2.280 in,or .030 over .Both saws list as using rod # 88623 ,which would lead me to believe that it would work ,but I don't know .I have both and from all apearances ,they seem to be the same. I know for a fact ,the air covers are the same,and would assume the recoil would interchange.The McCulloch parts lists,do not list an overbore,so perhaps,if it would work,the 125 piston would be an option .Try the file,it may work.

 

[heviarti]

I know for a fact the filter cover and recoil will work, and I need them. i really don't want to bastardize one of my 1-*0 flywheel covers if i can help it

The next pertinent tech questions are whether the 105's sleeve will accept an over-bore of .030, and if the 105 and 125 use the same rod, the question of stroke comes into play.. with the 105 at 1.635, and the 125 at 1.835, there could be some difference in the height of the piston from the top of the piston to the top of the the bore for the wrist pin.

It may be unnecessary to file the bore, as i turned the flywheel *GENTLY* through it's stroke and felt no grabbing, grinding, chattering or other bad feelings you can get between reciprocating metal parts. I then ran it through faster, and it feels fine even creating compression.

I have to see if i can find all the critical measurements for the piston to find out if wiseco maybe makes something.. and for that matter I also need to find kart interchangeability, because there may be a part available that way..

 

[Al Smith]

The tricky thing about the situation,is the fact that the 105 uses a "slipper"type piston.I don't know if any of the kart engines,other than the101,that used that style .If you are looking on e-bay for parts,chances are,more 125's will come up,than 105's.It is my assumption that both of these saws were basically used on the west coast,in the big trees,and the 105 never had the sales as the 125.

 

[heviarti]

well, If i could have had an ebay 125, I'd already have had one. 101 == 125? that would give me a .030 over kit.. I pretty much hauled this one off for a little or nothing. "I'm just selling the chain. you just have to take the whole saw to get it"

 

[heviarti]

Ok, So I was nearly crying while I drilled my 1-71's flywheel cover to accept the starter off my best 250... and not terribly surprised to hear it cough after I attatched it with the screws of my super 44a

What surprised the high holy dog-shi'ite out of me is when i hit it with a little starting fluid (after oiling the cylinder of course...) and it roared to life. I'm going to be busy for a few minutes feeling around in the cylinder with a wire to see wether i really need to hone it or not.. now i really need those other parts. If it will run reliably and under a load I have a stihl to go humiliate, lock washer shaped ding nonwithstanding..

which reminds me, Do these things use a 10-10 fuel line, or am I just stupid?

 

[heviarti]

well, i think i figured out just exactly how this whole thing happened with the saw.

I was cleaning it up tonight and noticed several things: the nuts on the PTO cover still have most of their finish, the diogs do too, and are razor sharp, the paint is all there, i can *wipe* the shmutz off the fins on the cylinder, and there is no streaking under the kill switch. The carb looks to have not had gasoline in it, and one lock washer was missing from the bolts that hold the carb on. As near as I can tell, Billy (the guy I got the saw from) had just finished kitting the HS124B in this saw, and did not realize he dropped one of the lockwashers into the reed case. He primed it off a squeeze bottle (he still does that) sucked the washer into the port, and the rest is history. and why was he rebuilding the carb on a saw with so few hours? the vacuum tube is cracked.

This is about as bad as the time he kitted my boss' carb in his 032 *FIVE DIFFERENT TIMES* before saying the saw was worn out. The high speed screw was bent.