ArboristSite.com Sponsors


McCulloch Chain Saws

vinnywv

vinnywv

Tinkerer
Joined
Aug 24, 2015
Messages
473
Age
44
Location
west virginia
Today worked out well for the cold weather. Yesterday i got a box of parts from bob johnson!!!!!!
Today i got the sp70 together and fired it up. Turned out very good. There were a lot of small screws missing or stripped. But sorting thru my peanut can of screws i had enough to get it together. It now wears a 24" bar and runs like a new saw. It should though. I was surprised. The new piston that bob sent was from lil red barn?? So i had to reuse the wrist pin. But it is a great runner. I made a few cuts and im very happy with it.
Then i moved on to the 6-10a, after some tinkering, i got a new piston in it. With a much better ring gap than what was in it. Its a great runner and fired right up no issues. I likely could have not replaced its piston but i had a new one and it was going to good useage.
Its a shame that mac didnt survive, or that they werent copied. Wonderful machines that continue to impress.
 
Jethro 2t sniffer

Jethro 2t sniffer

Addicted to ArboristSite
Joined
Mar 2, 2018
Messages
2,949
Age
32
Location
new zealand
Welcome to the club Homie ;) I’m happy for you.
Thanks man wasn't as crazy cheap as yours unfortunately but all good I'm happy. And thanks was allready a 82cc member but not the old type.

I like the 850 shroud setup. A dam fine saw.

The AV mount at the front fell apart when I pulled it out today 1 side fell off the other almost did. I've cut some rubber I've drilled some holes and hopefully at smoko I'll get it together and see how it goes.

It will be stiffer than original but doesn't worry me at all. The rear is much better and hopefully this up front will help take care of the rear.

Something I've noticed the 850 mounts have a hole through the rubber the 800 are solid rubber and probably a bit stiffer from new.

Also the rear mount on the end of the handle to the boot strap is also alot smaller and harder than the 850
 
Jethro 2t sniffer

Jethro 2t sniffer

Addicted to ArboristSite
Joined
Mar 2, 2018
Messages
2,949
Age
32
Location
new zealand
Today worked out well for the cold weather. Yesterday i got a box of parts from bob johnson!!!!!!
Today i got the sp70 together and fired it up. Turned out very good. There were a lot of small screws missing or stripped. But sorting thru my peanut can of screws i had enough to get it together. It now wears a 24" bar and runs like a new saw. It should though. I was surprised. The new piston that bob sent was from lil red barn?? So i had to reuse the wrist pin. But it is a great runner. I made a few cuts and im very happy with it.
Then i moved on to the 6-10a, after some tinkering, i got a new piston in it. With a much better ring gap than what was in it. Its a great runner and fired right up no issues. I likely could have not replaced its piston but i had a new one and it was going to good useage.
Its a shame that mac didnt survive, or that they werent copied. Wonderful machines that continue to impress.
Good job Vinny how do ya like that red barn piston?

Could ya throw the old 1 into the 7-10 from hell? Just for proof of concept
 
rwoods

rwoods

Addicted to ArboristSite
Joined
Feb 22, 2010
Messages
6,190
Location
Tennessee
Jethro,

MAC used to market a long bar kit for the 850. It was primarily A/V mounts without the holes. At some point the solid mounts became standard.

Ron
 
Jethro 2t sniffer

Jethro 2t sniffer

Addicted to ArboristSite
Joined
Mar 2, 2018
Messages
2,949
Age
32
Location
new zealand
Jethro,

MAC used to market a long bar kit for the 850. It was primarily A/V mounts without the holes. At some point the solid mounts became standard.

Ron
Thank you Ron I love these little bits of information.

I'm determined to make my own haha hate buying stuff I don't need to there expensive in nz pesos
 
vinnywv

vinnywv

Tinkerer
Joined
Aug 24, 2015
Messages
473
Age
44
Location
west virginia
Good job Vinny how do ya like that red barn piston?

Well, so far ive had good luck with them. Theres been one in my first mac saw from day one. I put one of them into my sp81. Its been thru many tanks of fuel in the few years ive had it. The wrist pins are the issue. They are not the proper size and you must reuse the originals. Not a big deal. Its out anyway, not like its extra work. But its lasted this long. I am not concerned about it.
 
heimannm

heimannm

Addicted to ArboristSite
Joined
Dec 28, 2005
Messages
9,834
Age
64
Location
Dike, Iowa
We had a visitor dropping this thread a while back that installed a LRB piston in an 800 or 850, he couldn't figure out why the wrist pin kept sliding over...not sure if we finally convinced him he had to use the original to properly fit the bore of the rod.

Mark
 
2broke2ride

2broke2ride

Addicted to ArboristSite
Joined
Jul 20, 2014
Messages
1,398
We had a visitor dropping this thread a while back that installed a LRB piston in an 800 or 850, he couldn't figure out why the wrist pin kept sliding over...not sure if we finally convinced him he had to use the original to properly fit the bore of the rod.

Mark
I remember that, didnt he eventually tear up the cylinder pretty bad?
 
2broke2ride

2broke2ride

Addicted to ArboristSite
Joined
Jul 20, 2014
Messages
1,398
I was taught years ago to "crosshatch" a piston much like honing a cylinder to help with oil retention. Is there any harm..... or good in doing this as far as you guys are concened?
 
kbeck

kbeck

ArboristSite Member
Joined
Nov 11, 2017
Messages
74
Age
64
Location
northern michigan
I was taught years ago to "crosshatch" a piston much like honing a cylinder to help with oil retention. Is there any harm..... or good in doing this as far as you guys are concened?
Iv'e seen that done to old snowmobile pistons, here's another take on that concept this piston was in a 1969/70 race motor.
Nice group of yellow you have there Jethro/like the antivibe fix 20200217_083716.jpg
 
2broke2ride

2broke2ride

Addicted to ArboristSite
Joined
Jul 20, 2014
Messages
1,398
It was/is a common practice to hone or otherwise deglaze an iron bore cylinder, not recommended for a chrome bore.

Mark
I agree 100% Mark, I was talking about the piston itself.
I was taught in tech school to take some scotchbrite or fine sandpaper and actually crosshatch the piston itself to help with oil retention.
 
Top