McCulloch Chain Saws

[vinnywv]

Ok, ive got a carb question....ive got a DE80 that ive had for several yrs sitting on a shelf in my basement because its just too clean to use. So today i got it down and decided i need to start it up. Put fuel in it and in a few pulls its running great. Its a great runner low hr saw. So i tuned it slightly and let it run awhile. So to my question, its got a sdc 85 carb on it. Ive read that its governed. How is it governed? I can see it on the side but how does it work? Im not willing to take it off and apart to figure it out. Any help on this? Just a curiosity. Nothing wrong with it. Thanks. Vinny

 

[rwoods]

Don’t know how it works. I have one of those too nice to run DE80s too. It winds out right at 10,000 rpms. About 2500+ below the other 82cc MACs.

Ron

 

[heimannm]

I believe Bob sold all of his Homelite parts, though he may have collected some more in his recent buy outs.

I think the governed carburetor have a ball type check valve that rattles at high RPM allowing a little extra fuel to pass and enrich the mixture to slow them down. There are threads about plugging the valve to remove the function but why would you if the saw pulls well under load?

Same for the fixed H carburetors, everyone I have (PM55, SP125, others...) works very well on a saw that actually cuts wood.

Mark

 

[edju1958]

I've been buying my Homelite parts from Bob for over a yr.& a half now & he's got tons of Homelite parts.
Ed

 

[Jethro 2t sniffer]

I believe Bob sold all of his Homelite parts, though he may have collected some more in his recent buy outs.

I think the governed carburetor have a ball type check valve that rattles at high RPM allowing a little extra fuel to pass and enrich the mixture to slow them down. There are threads about plugging the valve to remove the function but why would you if the saw pulls well under load?

Same for the fixed H carburetors, everyone I have (PM55, SP125, others...) works very well on a saw that actually cuts wood.

Mark

That's a rather simple governed system.

I agree on the fixed jet my 7-10 went really well on the "fixie". It has a sdc65 on it now rebuilt and the tilly fixed jet just had a bit more snap too it. Also the sdc44 powerd 7-10 has that same snap to it as well as the 700. The sdc65 on the 10-10 is also kind of iduno sort of limp lol still pulls good but doesn't have that brap heap hot rod feel

 

[Todd Loosli]

The big poulan chainsaws have that same type of governed system on them. Haven't messed with them yet but you can put a 4200 carb on and get rid of it,

 

[vinnywv]

Thanks mark, thats a bit different concept but whatever works right? Il not change it out. The engine is really good and probably because of it.
Jethro, ive tried that 65 carb before with similiar results. No snap. I took it back off.

 

[Jethro 2t sniffer]

The big poulan chainsaws have that same type of governed system on them. Haven't messed with them yet but you can put a 4200 carb on and get rid of it,

Nice to see you here on the yellow side Todd. It seems rpm was not a big concern with these bigger saws of that era green or yellow.

Thanks mark, thats a bit different concept but whatever works right? Il not change it out. The engine is really good and probably because of it.
Jethro, ive tried that 65 carb before with similiar results. No snap. I took it back off.

Interesting you found the same thing with the 65 Vinny did you cut with it? It seems to cut just fine. I've got 3 or the 65s the two I run (both rebuilt) behave like that

Todd is a poulan man has a shed full of very tasty green saws but he seams to be curious of the yellow team maybe 1 day he will run a nice Mac a 70cc 10 series will have him grinning

 

[Todd Loosli]

I cut my teeth on a mc 7 kart engine when they first came out cost me 75.00 dollars . I was 15 or so at the time, now that was a engine. Didn't know what I was doing but it sure was fun. We had some mac's in the military but they were junk as far as I could tell, hard to start.

 

[Jethro 2t sniffer]

I cut my teeth on a mc 7 kart engine when they first came out cost me 75.00 dollars . I was 15 or so at the time, now that was a engine. Didn't know what I was doing but it sure was fun. We had some mac's in the military but they were junk as far as I could tell, hard to start.

What a way to learn about engines. I think the starting issues were gone once the cube carbs were standard but I really have no clue

 

[vinnywv]

Nice to see you here on the yellow side Todd. It seems rpm was not a big concern with these bigger saws of that era green or yellow.


Interesting you found the same thing with the 65 Vinny did you cut with it? It seems to cut just fine. I've got 3 or the 65s the two I run (both rebuilt) behave like that

Todd is a poulan man has a shed full of very tasty green saws but he seams to be curious of the yellow team maybe 1 day he will run a nice Mac a 70cc 10 series will have him grinning

I did cut with it awhile. I just wasnt happy with it. Now ive got a 37 on that saw. Its happier as am i.

 

[Jethro 2t sniffer]

I did cut with it awhile. I just wasnt happy with it. Now ive got a 37 on that saw. Its happier as am i.

Well all is well then.

 

[Aaron Rybicki]

Hi all. Haven't posted in quite a while. Figured I'd post a couple pics of one of my SP81s since I got some down time. This saw runs around 193lb on the compression tester. Hell of a saw to pull over.. And it usually fires around 3rd pull. It idles/runs like any other saw I own. This saw has the fixed hi-jet carburetor on it. The pics I attached were it's first outing. I had just changed the PTO side crank seal about a week prior. When I fired it up, I noticed no issues, but when I sank the teeth in some wood, I noticed that she wanted to rev real high, so I had to feather the throttle to where it sounded about right. Around 3/4 throttle pressure. It chewed through the oak no problem but I was worried about pulling the throttle all the way back because it felt like the RPMs could've just kept going and going until she blew. Kind of weird with the fixed jet. It made me wonder if I had an adjustable Hi-Jet carb if I could tame it by making the hi-jet richer.

My wonder is.. Is it an issue with the fixed jet carb or is it an air leak. I'm probably going with air leak unfortunately...

 

[vinnywv]

Id say air. Reason being the fixed hi jet carb is made so it wont lean out and burn up your engine. If your running great at 3/4 throttle and then when you call for more fuel and air....your getting it. Check the boot. Ive had an pm800 act similiar. It was the boot. There was no tear or hole though. It was not a good seal on the fuel tank underside. I put a light bead of silicone on it and let it sit overnight. The next trial run was much better. I had to adjust the low side and idle. Apparently it was leaking all the time. I just didnt notice until full throttle. I hope its just a seal there and no tear in it. Good luck. Sp81's are fantastic chainsaws.

 

[Jethro 2t sniffer]

You buggers dam I need an sp81

 

[edju1958]

No you don't Jethro,it'll be just another saw to fix.Lol
Ed

 

[Jethro 2t sniffer]

No you don't Jethro,it'll be just another saw to fix.Lol
Ed

Hahaha but I like to fix them though Ed

 

[mogulmasher]

Ya we are all gluttons for punishment when you play with yellow saws. Once they are right though, it's worth it!

 

[Todd Loosli]

When you play with the green ones it's the same. Don't think the color makes it any more or less worth it. Saws are fun

 

[Jasonrkba]

I need some help identifying this one. I pick it up friday. Seller says it's a 7-10 but its hard to tell from the picture. No air filter cover. It looks like a 10-10 Pro but I suppose it could be several models. Im buying it regardless but was hoping there was something identifiable here.
than ks. Jason.