McCulloch Chain Saws

[Nardoo]

Hi Bob,
I made a mistake above - the piston I have for my standard PM1000 is a K900 (not K950). Your pic of the K950 looks much like my Super piston but like I said I do not have it in front of me and my memory is not what it was. I am fairly sure Jacob and others think they are a match. Here is what Leeha said in my earlier thread:

Great to see you'll have it up and running soon.
I installed an aftermarket piston that was listed
for the 1250 cut off saw in my R440 and it was
a perfect match.


(I am thinking he meant K950 as the K 1250 is 60mm) But it would be good to know for certain. When I have time I will go back inside.

Al.

 

[Nardoo]

There were two types of airfilter a screen and a flocked filter QUOTE]
Make that three types of filter. My Johnny has a flocked filter that is not held on by two screws but has a metal retaining strap. The filter is a single sided affair. Hard to describe but I can procure a pic of it.:msp_biggrin:

Al.

 

[ozflea]

Thanks Al sorry for rattling on but anyone who needs a piston will find this info handy as there bloody hard to find i have a Huskie 2100 piston here but its wrist pin size is larger therefore no go so close but no cigar

McBob.

 

[rwoods]

100cc Ten Series - Reality Check Questions

I have been eyeballing a DE80 cylinder tonight and I have taken some rough measurements. If bored 2.28" (not counting the plating thickness) there appears to only be about 1/8" of side wall left. Is this enough to survive? How thick is a typical plating? Ron

 

[ozflea]

Only a couple thou .....................

 

[rwoods]

Thanks. The critical question remains, will the thinned sidewall be enough? Ron

 

[leeha]

Nickasil plating can range from .005 to .015 thick.
According to US Chrome.



Lee

 

[rwoods]

I don't want to build a handheld bomb. 1/8" of cast aluminum seem awlful thin to me for a combustion chamber. Any thoughts beyond go for it? Thanks, Ron

 

[homelitejim]

we will have to increase the stroke to bring the piston back down to a manageable size.

 

[rwoods]

McCulloch - Don't leave home without one.

I wasn't feeling too chainsaw-ish today so I just took my 036Pro to cut this morning. I didn't know they had lined up a 30" plus shaggy bark hickory to be cut - and a field tree at that. Although the job got done I sure was sorry I left the 82cc MACs at home.

Today marked the official end of the 2011-12 firewood season at the ministry so I guess I can start on my own. I have a nice big red oak waiting on a 125. :msp_biggrin: Ron

 

[rwoods]

we will have to increase the stroke to bring the piston back down to a manageable size.

Unless we can find an interchangable crank (or at least one requiring minimal mods), I don't see this as economically feasible. I wonder if the three piece PM8200 crank could be outfitted with an offset pin???? :msp_unsure: Of course, we then have the port timing issues which are over my head. Clearances ??? Something to ponder. Our stroke with a stock piston would have to be in the neighborhood of 1.875" - in other words about 3/8" longer than stock. I wonder if we could get into the head 3/16"? Just when I thought our work was done. :msp_rolleyes: Ron

 

[homelitejim]

I wonder if the geniuses down at McCulloch have already pondered what we are trying to accomplish and found that it was improbable or impossible? The 82cc cylinder is really stuffed in there, I will get my calipers out and see how much room is left, I know it is not much. I will talk to my friend this afternoon and see what he thinks and if he would be interested in helping.

 

[54stude]

I wonder if the geniuses down at McCulloch have already pondered what we are trying to accomplish and found that it was improbable or impossible? The 82cc cylinder is really stuffed in there, I will get my calipers out and see how much room is left, I know it is not much. I will talk to my friend this afternoon and see what he thinks and if he would be interested in helping.

Just a question, would it be possible to machine the cylinder off of a 82cc crankcase, and bolt a cylinder on it from a newer saw. Maybe a 395 bb cylinder at 58mm?

 

[homelitejim]

Just a question, would it be possible to machine the cylinder off of a 82cc crankcase, and bolt a cylinder on it from a newer saw. Maybe a 395 bb cylinder at 58mm?

This is above my pay grade. I think the problem would be getting the exhaust and intake to match up as we do not want to re invent the wheel, just jam the largest motor we can into the original body work.

 

[Eccentric]

we will have to increase the stroke to bring the piston back down to a manageable size.

I wonder if the geniuses down at McCulloch have already pondered what we are trying to accomplish and found that it was improbable or impossible? The 82cc cylinder is really stuffed in there, I will get my calipers out and see how much room is left, I know it is not much. I will talk to my friend this afternoon and see what he thinks and if he would be interested in helping.

Jim do you have a crank to show him? Ask him about offset grinding the crank for more stroke. Of course then we'd get into conrod big-end bearing size issues......

The 99cc Macs such as the 550, 740, and 1-76 have a 2.165" bore and a 1.635" stroke. The 103cc Macs have the same stroke, but a 2.217" bore.

 

[homelitejim]

I do not have a 82cc engine but I do have a 72cc and a few 54cc engines laying around. Is the internals like the crank and rod different between the 72 and 82 cc engines?

 

[Eccentric]

I do not have a 82cc engine but I do have a 72cc and a few 54cc engines laying around. Is the internals like the crank and rod different between the 72 and 82 cc engines?

I have a McCulloch service bulletin that lays out the differences between the CP/SP70 saws and the SP-80. Rod big end is beefier with more rollers IIRC. There are some other differences. PM me your email address and I'll send you the SB.

 

[OldDeadWood]

Super 250

And now for something completely different.
View attachment 236021

View attachment 236022

If I did this right, you should be able the click the middle of this pic to run the video.

OK, It didn't work, so click here:[video]http://s1183.photobucket.com/albums/x467/OldWoodEye9/?action=view&current=Mcc250-09577.mp4[/video]

This is my Super 250 from the previous post. I've been adjusting the ports a little and a fiew other things and now I'm trying to tune her in.

This is a very aggressive chain on a 36" bar. I was hoping it would pull a lot better than this.

ODW

 

[ozflea]

And now for something completely different.
View attachment 236021

View attachment 236022

If I did this right, you should be able the click the middle of this pic to run the video.

OK, It didn't work, so click here:[video]http://s1183.photobucket.com/albums/x467/OldWoodEye9/?action=view&current=Mcc250-09577.mp4[/video]

This is my Super 250 from the previous post. I've been adjusting the ports a little and a fiew other things and now I'm trying to tune her in.

This is a very aggressive chain on a 36" bar. I was hoping it would pull a lot better than this.

ODW

Well whats wrong with that after all its only 87cc sure i could go a bit quicker get the chain right

McBob.

 

[dieselsmoke]

Hey Woodie, your S250 runs awesome.. I scrolled thru your videos, and man that 840 is bad-azzz. Maybe you could provide some technical details.