MCCULLOCH The official McCulloch thread

[Maintenance Chief]

Ive had some success with this.

 

[Maintenance Chief]

?

 

[PogoInTheWoods]

Stihl 034/036/038/064. The later 026 line is also said to work. I have one of Mark's lines in my 7-10. Very nice solution.

 

[Bigmac]

This is one option for the fuel line.

https://www.ebay.com/itm/guaranteed...760123?hash=item1ce5479d7b:g:xa0AAOSwL-Bc37i4

Mark

I have used a bunch of those!

 

[Al Smith]

I have used some Stihl fuel lines on Macs with success and many that didn't work .I've got a good sized collection of them .I did have some luck at one time finding OEM McCulloch at MFG supply .
I've tried several half-fast fixes using Tygon fuel line etc but often failed .I caught my Husky 2100 cd on fire once trying to be a cheapskate .Finally found a new OEM which cost about 20 bucks .Catch a saw on fire some time,not fun . I gave up on those cheap fixes a long time ago .

 

[Dream]

Yep. Flaming chainsaws are best left to the professional performers.
I cant juggle anyway.
I keep a fire extinguisher in the truck for just such emergencies.

 

[Al Smith]

Well in my case it was a test startup and close to a water hose .It it were in the woods the only thing you could do is pizz on it I suppose .At any rate no more half-fast fixes for me .

 

[Dream]

Which reminds me, ive got a couple of gas caps I need to fix.

 

[popopboat]

Hello everyone, seems like that i can join this thread too
Recently bought two SP81, today they finally arrived!

One appears to be in pristine shape, rubber parts are literally like new, hangs by the starter rope for solid 12 seconds.
While the other one... not so a great story, seems like a cold seizure, someone was too impatient to wait.
Luckily (IMO) it might be saved, cylinder is not that terrible, has a thin line all the way through to aluminum but the rest is pretty good.

What do you say?

 

[popopboat]

Wanted to clean carb on the working one, found 2 membranes??? I dont remember last carb that had 2. Did someone mess up ?
or really 2 membranes

 

[Al Smith]

Get some fine lapping paper and sand out the piston .You'll never know the difference .I forgot who I sent the lapping paper to but I think is was an 8200 .Sanded it out,back together runs fine . You could probably find rings for it some place if you look or they might be fine once they get unstuck .Those Macs will take a lot stuck or unstuck .I had one ,a 700 that was stuck tight .A little penetrating oil soak,move a little,next day a little more until it was free .never pulled it down and it runs like a top .

 

[heimannm]

The two diaphragms are typical of certain carburetor kits. As you can see, the black rubber one provides the sealing flaps and pumping membrane, the tan Mylar one is just a back up to insure good sealing of the flaps.

If the aluminum transfer will clean out of the cylinder O.K. you should be able to find a new piston for that saw. Look closely at the head of the cylinder to see if there is a letter stamped on it. The SP81's were fit with "A", "B", or "C" pistons that were each slight different in diameter. If there is no letter it is a "B" cylinder and uses piston assembly 92519, or 87791 as an alternative. The piston kits come with piston rings and wrist pin bearings.

Mark

 

[Al Smith]

There's a zillion ways to do things and I'm not suggesting mine is the best but here goes .On what few Macs I've had that were hung and needed some attention I first remove any transfer then buff the piston,might sand or might not .Then using the piston with no rings and check for fit .You can tell with an oiled piston if it hits a snag then find it .It should hold enough enough compression up above he exhaust port to show resistance once the compression builds up as it goes deeper into the bore .Of course with no rings it won't hold it .Evidently on this hodge podge of swapping parts I've never found larger diameter piston I've tried to jamb in a smaller bore .Then again I haven't done that many .

 

[popopboat]

Well, definitely would like to reuse this piston because of the money reasons, but will see what will i do, maybe replacement in the future if i find one.

Firstly, need to "fix" the "working" one, its running great, accelerates beautifully, im actually suprised how little it vibrates...i like it!
But, when i dig it in the wood (full throttle), it works for 4-5 seconds and then starts bogging down, and recovers after 2-3 seconds of idle, knew that something is wrong with fuel delivery...
Cleaned carb, but not much of a difference, then just like that it wouldnt start at all... and for no reason i poked my finger in the fuel tank just to discover "bent" fuel line, BUT that wasnt the problem neither...
Then i removed carb gasket just to find out that the imuplse hole is literally connected to the intake, not much, little hole in the wall between, now i sealed it temporary with RTV to see if that was the problem, most likely, ill get jb weld or some kind of epoxy and fix it more permanently.

 

[popopboat]

Ok i did a silly thing now, failed to fight an urge not to do a complete rebuild.
Seems like theyve been repaired before.. But i want to be sure that its been done properly.
Saw probalby heard my thoughts and maybe from excitement or anger bit me. You guys should have warned me!

 

[popopboat]

Uh oh... This doesnt seem like transfers
Interesting part is that it hangs by a starter rope for solid 12 seconds cold and 15 hot.

 

[fossil]

A lot of chrome MIA.

 

[Dream]

Uh oh... This doesnt seem like transfers
Interesting part is that it hangs by a starter rope for solid 12 seconds cold and 15 hot.

View attachment 248310

Cylinder is done anyways. If its got good compression, id run that sucker til it wore completely out. Mix the oil a bit rich and dont lug it hard. Dont want it getting too hot. If you dont have transfer on the piston it may run for a long time.

 

[Al Smith]

Looks like toast to me

 

[Al Smith]

I'd say pop the other one apart and put the best parts to one .