McCulloch Chain Saws

[2broke2ride]

Mark,
Spring and check ball are present and accounted for....... not really sure what I'm looking for here.
Why would it to be hard to block off the oil pump? It looks like all I would have to do is make a blank gasket for the oil tank threat blocks the impulse hole. Or am I missing something

 

[ML12]

I have at least one mac block where the manual oil push rod passage cross drilled through one of the clutch area dust shield mounts (screw hole) which went through to the crankcase and caused an air leak. This was in the bottom boss of the block however. It took a bit to find it, could be something similar?

 

[cpr]

'Preciate the offer, Tim, but I'll take my chances. I see no evidence of any actual cracks and feel a little better knowing Mark has a few similar ones, too.

I flushed the carb with a few cycles in the USC and kitted it with relatively good results. Settles in nicely between 2300 and 2500 RPM now with the 'L' right around 1 turn out but the idle screw adjustment is extreme to achieve that. Also need to choke it to re-start if it sits for more than a few minutes even though it's still hot. The PM800 behaves more like I would expect the 8200 to behave. I'm leaving the 'H' pretty fat until I can get it into some wood then I'll let her rip and see what how it holds up. Not sure if that may be having an adverse effect on the 'L' adjust with this saw. I leaned it out a little at low RPM's without much difference in the 'L' response, tho.

So what say ye wise ol' sages about this extreme idle screw adjustment? And is there a clever solution for the lack of a spring in an impulse line? Pretty sure that's my problem with the SP81. Looks like a kink about midway where the bend is the most severe.

As usual fellas, thanks for the input.

View attachment 578239​

With that much idle preset, does it place the throttle blade between the idle jet and the booster jet? If so, did you pop the welch plug? Probably something in there blocking it that the ultrasonic couldn't eradicate.

 

[heimannm]

2broke - Hard part is taking it all back apart again to make it original when that does not cure the ill.

Mark

 

[PogoInTheWoods]

It may help reveal (an)other leak(s), though. I've fixed an obvious large leak just to find another smaller one more than once.

 

[PogoInTheWoods]

I have never seen a problem with the impulse line on the anti-vibe 10 Series but I'm sure it can happen, must be why they show the spring in there.

I replaced the line on the SP81 and ended up with the same results so I think you are probably right and the original one was still ok even though it looked flattened at the bend. Basic piece of 3/16" ID braided rubber outdoor power equipment hose fit nice and snug and held its shape as Tim suggested. Something weird is still going on and I'm now leaning toward a timing issue as around 3.5K is about it for for top end. Pretty sure I set the points (new) at .018 and there's definitely a flywheel key, albeit from a 10-10 carcass, but it seemed to fit as it should. Also wants to tear my hand off on a re-start even using the compression release like it's instantly firing (but not starting) before I've even pulled an entire revolution. I'm new to the points game, or at least having to troubleshoot points problems. Any t-shooting tips or tricks here would certainly be appreciated. Condenser is from a MiniMac and I have great spark fwiw. Carb is a very clean and totally rebuilt SDC.

Back to the PM8200...

With that much idle preset, does it place the throttle blade between the idle jet and the booster jet? If so, did you pop the welch plug? Probably something in there blocking it that the ultrasonic couldn't eradicate.

Not sure what that particular position would be relative to the idle and booster jets but here's a pic of how far the throttle plate is open to obtain my current idle. Did not replace the welch plug. Only had a D kit for it at the time. I've since acquired a couple of K's so could do it if necessary except the saw starts, runs, and idles nicely now. Only oddity is having to choke it and lock the throttle open on a hot re-start if it's been sitting for more than a few minutes...., which also seems like it could possibly be a symptom of your point about debris under the welch plug.

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I find those 10 series MACS a pain in the butt to work on. Too many three handed jobs.

Hell, Tim..., quit usin' yer butt as a third hand!

I love working on these saws. I connect with them differently than other saws for some reason. (Lack of plastic maybe?) LOL. I've been wanting to get into my yellow pile for awhile and always seemed sidetracked with other projects. I'm really happy to finally have the time to start giving them some long overdue attention. Very gratifying and lots o' fun, though indeed a bit frustrating at times!

 

[fossil]

I replaced the line on the SP81 and ended up with the same results so I think you are probably right and the original one was still ok even though it looked flattened at the bend. Basic piece of 3/16" ID braided rubber outdoor power equipment hose fit nice and snug and held its shape as Tim suggested. Something weird is still going on and I'm now leaning toward a timing issue as around 3.5K is about it for for top end. Pretty sure I set the points (new) at .018 and there's definitely a flywheel key, albeit from a 10-10 carcass, but it seemed to fit as it should. Also wants to tear my hand off on a re-start even using the compression release like it's instantly firing (but not starting) before I've even pulled an entire revolution. I'm new to the points game, or at least having to troubleshoot points problems. Any t-shooting tips or tricks here would certainly be appreciated. Condenser is from a MiniMac and I have great spark fwiw. Carb is a very clean and totally rebuilt SDC.

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Hell, Tim..., quit usin' yer butt as a third hand!

!

My butt isn't even any good for sitting on.

And...
Onto breaker points.
I will take points any day over electronics. Simple and reliable. Another nice thing is you can tell exactly the point that the spark occurs which can vary with electronic units depending upon the intended design.

The spark will fire as soon as the points open. The advance should be around 30 degrees before top dead center. If you pull the flywheel off and determine at what spot the points open (ohm meter), the piston should be about 30 degrees before TDC. If it's way off, you need to fix that. Too much advance is not good.

I have to ask this as I came across it once. Are you sure the coil you are using is a points coil and not a module?
If the saw gets two signals to fire it will like likely idle fine but run like crap at higher RPM's.

The mini MAC condenser is A OK.

I have an SP80 and it is a strong runner. I like it alot. It's the only 82cc 10 series I have.

 

[PogoInTheWoods]

I have to ask this as I came across it once. Are you sure the coil you are using is a points coil and not a module?

It's certainly a valid question. I believe we determined it to be a points coil back during that period of my initial questions and head scratching. It already had an addon chip replacing the points and I wanted to go back to the points setup as you may recall. Posted this pic for discussion...

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As for adjusting the points, I understand it to simply be the gap adjustment when they're at the top of the lobe (given the correct flywheel and key) and the timing should pretty much be where it's supposed to be as a result. Should I be paying closer attention to obtaining an actual optimum timing number somehow? Doesn't seem like a degree wheel or timing light should be necessary to set these up!

 

[fossil]

It's certainly a valid question. I believe we determined it to be a points coil back during that period of my initial questions and head scratching. It already had an addon chip replacing the points and I wanted to go back to the points setup as you may recall. Posted this pic for discussion...

View attachment 578958
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As for adjusting the points, I understand it to simply be the gap adjustment when they're at the top of the lobe (given the correct flywheel and key) and the timing should pretty much be where it's supposed to be as a result. Should I be paying closer attention to obtaining an actual optimum timing number somehow? Doesn't seem like a degree wheel or timing light should be necessary to set these up!

You can affect the timing with the points gap. The wider the gap, the sooner the points open and you get mpfe timing advance ,to a point, and not that much more.

You can always check if the coil is a module. Remove the wire from the points box at the coil and check for spark at the plug. If it's there, you have a module.

 

[PogoInTheWoods]

Good idea. Thanks.

Wonder how that chip would have behaved if the coil is an electronic module. Same timing as the coil I would think..., with spark you could weld with.

 

[Brian Thacker]

I bought 3 of these chips (Nova) and put them in 3 of my saws. I loved how well they started with these chips and seamed to perform better with them, but, each one of them failed very quickly. I was very disappointed that they failed with in just an hour of use and I had them in a place where the fan drew outside air over them before the air went to the motor. Get rid of it and go back to points. I got such good spark from the chip and at a much lower RPM than points which made starting easier and better, but in the end they failed within an hour of operation. I would love to find a chip that would last but I know the Nova chip is no good and would bet it is your problem.

Brian

 

[joeymt33]

I bought 3 of these chips (Nova) and put them in 3 of my saws. I loved how well they started with these chips and seamed to perform better with them, but, each one of them failed very quickly. I was very disappointed that they failed with in just an hour of use and I had them in a place where the fan drew outside air over them before the air went to the motor. Get rid of it and go back to points. I got such good spark from the chip and at a much lower RPM than points which made starting easier and better, but in the end they failed within an hour of operation. I would love to find a chip that would last but I know the Nova chip is no good and would bet it is your problem.

Brian

That's strange, I've been running nova chips on some 82cc saws for years now. I put it on the crankcase side away from the engine tho.


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[PogoInTheWoods]

Get rid of it and go back to points.

I never used the chip. The pic just shows it as how I got the saw. I rebuilt the saw with points as previously explained.

 

[astnmacgto]

That's strange, I've been running nova chips on some 82cc saws for years now. I put it on the crankcase side away from the engine tho.


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same, I have chips in a few saws and they have been going strong for many many hours, mine came from napa

 

[Massey]

Hello there , I'm a newbie on those yellow saws and tomorrow I gonna see this one but I don't know what it is ; 797 or 795 maybe but the experts can tell me more


I thank you by advance for the help

 

[cpr]

That's a 1-70. Very much worth having for the right price.

 

[heimannm]

Yes - 1-70, 80cc, very nice condition too. The black, cast AF cover and external points/condenser are the sure signs.

I have a 1-80 in similar condition just begging for some wood.

And a P.S., good to see you posting Charles.

Mark

 

[fossil]

Good idea. Thanks.

Wonder how that chip would have behaved if the coil is an electronic module. Same timing as the coil I would think..., with spark you could weld with.

The few chipped saws I have seem to run with more advance than the stock ignition on the same model. They will all kick back a bit if you pull the starter too slowly.

That includes three of the grey chips (Nova?) and two of the a factory chipped XL-76 type saws. I have a 7-10 thatt's chipped as well with a high speed miss. Not sure if it's the coil or the chip as the points system save for the box is MIA.

 

[Massey]

Thank you a lot for the information , I was far away by thinkin' 797 ! It runs and has a lot of compression but "maybe need tuning" that's what the seller said to me .

 

[PogoInTheWoods]

On a different topic, were McCulloch replaceable sprocket nose bars generally Windsor speed tips? I have one needing a tip (3 rivet style) and there's not much out there in 3/8 .050. Plenty of .404. Found a guy in N.C. that has what appears to be the correct replacement in a Windsor tip. part# SRA-222-B1C. Another guy in Maine has an Oregon replacement for a Windsor that looks the same. Just curious if I'm on the right track. Seems like there would be more sources.