McCulloch Chain Saws

[clint53]

So, 2 of the 3 saws are Q-ports and have the 600439 D tags.
That's the two Vinny said were not 850's.
Is it a better chance they are SP-81E's now? Serial number has a 14 prefix.
I looked at all 3 through the spark plug hole with the Endoscope.
I picked the better looking one and pulled the muffler.
This is what I found.

It also had the best bearings. Zero end or side play.
I think I have the seals. I must look at the IPL first.
I have the makings of an 82cc saw in progress.
Clint

 

[Maintenance supervisor]

Didn't you yank the canister muffler on that 800 in favor of an 850 version and re-work the shroud for the necessary airflow to minimize excessive heat build-up?

I actually just cut the entire front of the muffler off and sealed it past the exhaust port under the saw.
No shroud work. I think reducing the heat certainly helps.

 

[clint53]

Didn't you yank the canister muffler on that 800 in favor of an 850 version and re-work the shroud for the necessary airflow to minimize excessive heat build-up?

That is my very plan Pogo. I don't like that massive muffler at all.

 

[vinnywv]

Yea 850 cylinders did not have the q port. Perhaps the super 850 but not pm850. It was a sp81 late style with the elec ignition coil mounting. The 850 and sp81 both have the same transfers with the bridge in the middle but no q port exhaust. The early sp81 had an open transfer that was a bit smaller overall. But the same intake and exhaust. The q port was the 800, 805, de80, 8200 saws.

If you guys recall jethros pm800 muffler, he made it smaller like the 81, 850, 80 saws. That 800 saw of his cutting those big trees is very stout. The big change was the muffler. In his videos that 800 is quite a machine.

 

[vinnywv]

That piston looks good from here. If the cylinder is good too...definately can make a great saw out of it!! Very good find.

 

[clint53]

Yea 850 cylinders did not have the q port. Perhaps the super 850 but not pm850. It was a sp81 late style with the elec ignition coil mounting. The 850 and sp81 both have the same transfers with the bridge in the middle but no q port exhaust. The early sp81 had an open transfer that was a bit smaller overall. But the same intake and exhaust. The q port was the 800, 805, de80, 8200 saws.

If you guys recall jethros pm800 muffler, he made it smaller like the 81, 850, 80 saws. That 800 saw of his cutting those big trees is very stout. The big change was the muffler. In his videos that 800 is quite a machine.

Thanks Vinny.
Since I made that last post and I agree with you. 800 or 805.
It really makes no difference, I wanted a 82cc and now have one.
I checked my seals. I have them.
So maybe by tomorrow I'll have it running.
I don't have a Mac bar over 20". That will not do. It deserves a 24 or 28.

 

[rwoods]

Would be interesting to see if there's any significant performance difference relining a Q-port cylinder without the Q-port. Seems like the Q-port and the muffler differences are what mainly distinguish the PM850 and SP81 from the other 82cc saws.

There is also a slight intake difference between the two as well. I can't access my pictures from here but maybe vinnywv has a screen shot of the pictures I posted several years ago that shows them side by side.

Ron

 

[Xpropane]

So, 2 of the 3 saws are Q-ports and have the 600439 D tags.
That's the two Vinny said were not 850's.
Is it a better chance they are SP-81E's now? Serial number has a 14 prefix.
I looked at all 3 through the spark plug hole with the Endoscope.
I picked the better looking one and pulled the muffler.
This is what I found.
View attachment 969723
It also had the best bearings. Zero end or side play.
I think I have the seals. I must look at the IPL first.
I have the makings of an 82cc saw in progress.
Clint

That's excellent news , we are happy it's working out so well. Way to get after it and get what you wanted!
Eric R.

 

[clint53]

That's excellent news , we are happy it's working out so well. Way to get after it and get what you wanted!
Eric R.

Thanks Eric.
I'm after it hard.
The weather here is wonderful and I really like working on them outside.
About 30 minutes in the basement and I'm done.

 

[big10pointer]

I keep you in mind when I go back to get the rest.
I really don't know what all is there.

Thanks Clint that is very Kind of you.

 

[Jethro 2t sniffer]

Yea 850 cylinders did not have the q port. Perhaps the super 850 but not pm850. It was a sp81 late style with the elec ignition coil mounting. The 850 and sp81 both have the same transfers with the bridge in the middle but no q port exhaust. The early sp81 had an open transfer that was a bit smaller overall. But the same intake and exhaust. The q port was the 800, 805, de80, 8200 saws.

If you guys recall jethros pm800 muffler, he made it smaller like the 81, 850, 80 saws. That 800 saw of his cutting those big trees is very stout. The big change was the muffler. In his videos that 800 is quite a machine.

I was going to cut up mine originally and build a duct out of it but snagged a 81 duct of ebay shipped to me for 80nz bucks. Your right though that was the plan and I did make my own cover up. It has like a 50mm by 30mm opening. Just enough to fit behind the clutch cover. Big big difference its not behind the 81 or 850 at all infact I feel it's almost stronger in the upper rev range.

I used inspiration from fossil for the cover and Ron helped with the air shroud.

100percent worth it.

The big muffler I feel was a band aid and yeah was clever it did make it quieter and did reduce the fire issue and made use of an empty space but really let's be honest in the early 80s they really needed a new design.

Really happy for you clint. Hunt down a duct style muffler for your Qport but don't stress on it 82cc's in any form are awesome

 

[Jethro 2t sniffer]

Might be 20mm either way its a big hole and muffles nothing

This was first run with the muffler done

Semi chisel chain in very nice macrocarpa

 

[Jethro 2t sniffer]

Here is the shroud.
And my first attempt at a cover.
It worked good as except broke in half. I was thinking wow this is cutting well holly crap but seems loud. Had a gander and then saw it missing the bottom section. Turned the hi out a fly sh!t n carried on. I new then I needed to replicate it.

The 850 I yanked the read n screen and bent open the read stop a little. Probably really should get a special 1 on from vinny now I have a short cover for it

The 81 has a homebuilt from someone else and I pulled the screan also.

Should add the duct on the 800 is not quite a bolt on n go. There is nothing to screw the cover on to as the cylinder has no bosses. I welded some nuts on the back instead. The top 800 muffler mount fits good but needs a hole too and I welded a nut on the inside.

The two bolts/screws into the bottom around the exhaust port don't swap over either. Will need non Q screws or like I did cut the head off make them the correct length weld back on and also hour glass shape them for flow.

 

[vinnywv]

If nothing else just to hear it pop. It sounds awesome. I did cut the length on mine to suit but it cuts great and sounds mean.

 

[clint53]

Here is the shroud. View attachment 969800
And my first attempt at a cover. View attachment 969801
It worked good as except broke in half. I was thinking wow this is cutting well holly crap but seems loud. Had a gander and then saw it missing the bottom section. Turned the hi out a fly sh!t n carried on. I new then I needed to replicate it.

The 850 I yanked the read n screen and bent open the read stop a little. Probably really should get a special 1 on from vinny now I have a short cover for it

The 81 has a homebuilt from someone else and I pulled the screan also.

Should add the duct on the 800 is not quite a bolt on n go. There is nothing to screw the cover on to as the cylinder has no bosses. I welded some nuts on the back instead. The top 800 muffler mount fits good but needs a hole too and I welded a nut on the inside.

The two bolts/screws into the bottom around the exhaust port don't swap over either. Will need non Q screws or like I did cut the head off make them the correct length weld back on and also hour glass shape them for flow.

Thanks Jethro.
I'm going to start with the 850 muffler. I don't know what else I left behind.
I'm going back maybe Friday and make an offer on the pile of saws and parts.
Clint

 

[clint53]

I just have to say this guys.
An exhaust Q-port goes against everything I believe and have learned about building a saw with high compression and torque.
Clint

 

[big10pointer]

I just have to say this guys.
An exhaust Q-port goes against everything I believe and have learned about building a saw with high compression and torque.
Clint

I completely agree with you Clint the Q-port does rob some power from the saw. I was thinking last night how hard would it be to weld it up and smooth it so the rings don't touch it. Not sure that its worth the effort though.

 

[rwoods]

I don’t know enough to weigh in on the power effect of the Qport, but you will note the balance of the exhaust port seems smaller than the pre-Qs which I take as evidence that it was carefully engineered. FWIW I am told similar porting was done in the M/C world.

Ron

 

[clint53]

I completely agree with you Clint the Q-port does rob some power from the saw. I was thinking last night how hard would it be to weld it up and smooth it so the rings don't touch it. Not sure that its worth the effort though.

I thought about it also. I believe it would have to help it some.
I have bunches of XL-12's. I thought about getting one running well and cut with it and then do a Q-port and cut with it again, just to prove the point to myself.
I could do compression test, check RPM's in the cut and out, time the cuts, etc. All done before and after the Q-port.

 

[PogoInTheWoods]

If you guys recall jethros pm800 muffler, he made it smaller like the 81, 850, 80 saws.

I was going to cut up mine originally and build a duct out of it but snagged a 81 duct of ebay shipped to me for 80nz bucks. Your right though that was the plan and I did make my own cover up. It has like a 50mm by 30mm opening. Just enough to fit behind the clutch cover. Big big difference its not behind the 81 or 850 at all infact I feel it's almost stronger in the upper rev range.

Thanks for the clarification and clearing up a foggy memory..., at least temporarily!

And I'm pretty sure a PM850 Super is just a PM800 with a different sticker and paint job.