found out why the Mac SP125C i kept wont run!

[NWCS]

decided to strip the Mcculloch SP125C i have left and see why compression was 75psi max.. upon muffler removal.. the stomach turning started.. not much of a piston left.. stripped the engine down and.. the entire exhaust side of the piston is destroyed! opposite side still ideal condition.. wow! also mud like residue pooled on the bottom of the block.. last owner must have not liked air filters or something! i have a good used piston i can slap in the block..
some chrome missing but its all i got!
anybody have a set of rings for a standard SP125C piston? seems to be a thin ring, rings match the size on the piston listed below. .024 thick


if the cyl was perfect i would be after a CP125 connecting rod so i could use this NOS thin ring piston ive had sitting around (bearings are in the piston, not the bearing in the connecting rod) that piston is still available if anybody wants to make an offer (PN 69241)

 

[NWCS]

heres a picture of the damage.

 

[sedanman]

Call U.S. Chrome and have the cylinder fixed, to your bore specification and use the n.o.s. piston. http://www.uschrome.com/

 

[Al Smith]

Seems like I've seen this before[my own],ugh. An option,but not the best,would be to buff out the piston ,using a buffing wheel and rouge.I had one,although not as bad,that I saved,and so far I haven't had any trouble ,yet.The best solution,of course,would be to rechrome,or reline and install a new piston,but sometimes you gotta do what you gotta do.

 

[ozflea]

Bad find there old fella it looks kinda nasty, i found a 90 % complete 125 last friday and it has a good cyl and piston assy but i'm chasing the rubber connector that goes between the airbox/fuel tank assy and the inlet manifold as mine is split and now buggered, wouldn't mind a fan housing as well again the one on the saw is cracked.
Anyone out there got any sawdust guards to suit the 125 ??

Mc Bob.

Got our first light frost for this winter this morning, in future i'm just stay in bed bugger it it's to cold out there.

 

[Al Smith]

Are you talking about the one that goes under the clutch assembly,Bob?Oh,by the way,it's spring time on this side of the big pond,aha

 

[ozflea]

It's about an 1" in diameter you have to take the fuel tank off to get to it, it's spring loaded and seats on the intake manifold, the top forms the seal to the carby and is retained by two screws each side of the carby.

Mc Bob.

 

[Al Smith]

Got it ,Oz ! I'll send a picture through regular e-mail after my wife gets off the other computer,where my camera stuff is attached.As it is,I have my 5 mega pixel camera on this computer,and the smaller one,on the other.The 5 is way too large to send through e-mail,or to this site,for that matter but it does take nice pictures.

 

[056kid]

i got one of them to

 

[ozflea]

Well 056 kid if ya want to get rid of it give me a yell, as i'm geting a few 125's together right now and need a few spares.

Mc Bob.

 

[Oregon_Native]

found a cp125 on ebay might use same parts.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=79667&item=4385928140&rd=1

 

[Al Smith]

It won't stay that cheap,trust me.

 

[ozflea]

And quess what i don't have a CP 125.

Mc Bob.

 

[NWCS]

what are the diffrences in the CP and SP? outside diffrences i see is pretty much the muffler/cover. anything else?

 

[ozflea]

I feel that the main difference was in the cylinder wasn't the CP a reborable one and the SP a chrome cylinder plus the decompressors are different. Otherwise the saw are basically the same.

Mc Bob.

 

[ozflea]

Oh by the way i got my second Super Pro 125 up and running but still needing a few more bit's and pieces to finish her off.

Mc Bob.

 

[Al Smith]

I don't know about the differences,other than the style of the decomp valve.I also think the Cp had a piston like a 101 kart engine,with the bearings in the piston instead of the rod.About the sp cylinder.I have an sp 125 and a sp 125c.The sp is an iron cylinder,the spc was a chrome one until I turned and pressed a new liner.According to Macman,they all had a combo of iron or chrome cylinders.I really don't know,except the ones I have.

 

[056kid]

i want to get my CP running. The rings where out of round and compresson was terrible. I imagin that the jug needs reboring. After that, impuls/fuel lines, some gaskets and a carb kit should have her cranking.

 

[Al Smith]

Pshaw,the guy pulled the sale of the cp on e-bay.What's the deal on that ,I wonder,geesh I was winning.

 

[ozflea]

Consider yourself lucky old mate i was gonna sap ya (snipe) at the last moment.

Mc Bob.

Never rest easy when i'm around.