Thanks Poge!
Also picked up a good used 7-10 cylinder and rotating assembly to replace the blown up 7-10 I have
Also picked up a good used 7-10 cylinder and rotating assembly to replace the blown up 7-10 I have
McCulloch Chain Saws
- Thread starter Bruce Hopf
- Start date
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I've got two 7-10 IPLs and both say thin 85239piston 89732ring set they are 76 and 77 so very late 7-10. It has (thin) beside it but no mention of (thick) or its numbers.
Interesting 1 of them is a 7-10 power unit and not chain saw. Everything is the same except it has no parts or pictures for an oiler
Interesting 1 of them is a 7-10 power unit and not chain saw. Everything is the same except it has no parts or pictures for an oiler
Ahh see Ron was right you don't have parts saws its saws waiting for part's haha. That was a good find
Yep I was thinking the same thing!
Went to work cleaning things up on the 7-10. Took it over to the buffer and polished the piston up a bit 
Went to work cleaning things up on the 7-10. Took it over to the buffer and polished the piston up a bit
View attachment 792529
A bit lol. Its like a mirror
I may be a little concerned about retaining lubrication with such a glossy surface.
Pretty sure 700 is open transfers. I have one apart at home. I will try and take a pic tonight.
Yeah there all open transfers but the 700 has a bridge in the transfer the 7-10 doesn't.
Thanks for taking some pictures my camera is buggerd so I can't
It's old for sure.
Is the “bridge” the same as the divider? I believe someone here has some MAC literature that says the divider was added to the 82cc saws (later SP80 or the SP81 not sure which) because it produced more power. Maybe they did the same for the 70cc model change and didn’t get the same results. Funny if all else is the same.
Ron
Yeah divider that's the correct term. I was thinking about that with the 82cc saws too. You would think they would of tested the hell of them enough to notice a performance change and fixed it. It just seems odd. Unless it was a reliability thing but there's more than 1 or two 7-10s still earning there keep long after there original owners have ummm expired
It' really hard to fix a power speed t a saw when they are so old. I have a late 700 that will cut with a 7-10 but the 700 is a lot fresher than my 7-10's.
I usually defer to Mark who has a lot of NOS parts.
A bridge would be a divider in the transfers. I'm guessing they added velocity. Some open port saws have three transfers or two dividers.
I usually defer to Mark who has a lot of NOS parts.
A bridge would be a divider in the transfers. I'm guessing they added velocity. Some open port saws have three transfers or two dividers.
I guess you can’t always rely on the marketing literature. MAC also says the PM800 makes more horsepower than the PM850, but almost uniformly owners of both here say otherwise. I say make your saw run the best you can and go cut. Chain is where a lot of performance is gained or lost. I need to up my game there the most.
Ron
Ron
Yeah good points guy's. It was more a curiosity thing really my 700 is fairly tired and so is 1 of my 7-10s but both run really well and pull 20 inch bars perfectly I can't hardly tell a difference at all apart from weight ofcourse.
Both hang on the cord for about 8 seconds before turning over a notch
Absolutely chain is a massive factor no denying that. Brian says your sharpening is very good Ron
Both hang on the cord for about 8 seconds before turning over a notch
Absolutely chain is a massive factor no denying that. Brian says your sharpening is very good Ron
I beg to differ. I am very inconsistent. And out the box is almost always the sharpest they will ever be. Ron
I figured piston smooth in the bore and let the rings do the work. Not something I would do to a new piston.
