McCulloch Chain Saws

[HeRoze]

yep, timing.

Should open just as you say and should be about .018-.021 gap on the points. A little less will advance the timing, a little more retard it. Check the plug gap or even give it a new plug. Whats the compression?

plug is new. no idea on the compression other than the arm-meter seems okay.

 

[HeRoze]

... and that confused me an I wrote it... here's a sketch, if that helps. (sorry so big, no way to resize on AS)

 

[mcbob]

... and that confused me an I wrote it... here's a sketch, if that helps. (sorry so big, no way to resize on AS)

Check the oiston to bore clearance could be just plain worn out .......................

 

[ozflea]

Did you check piston to bore clearance and the rings could be jusy plain ol worn out

McBob.

 

[a. palmer jr.]

I'm stumped. Got a d-36 back together. replaced a few parts (bearings/seals, starter gizmo, trigger, fuel lines w/a rigged pick up line), took apart and cleaned everything down to piece-parts (carb, reeds) and repaired the clutch cover. Got a nice blade on her.

it gets hot spark. it will NOT turn over. starter seems to be engaging fine. shot prime in the carb, and then finally in the chamber. still no luck. any idea is a good idea right now.... vic

I don't see anything about compression....

 

[heimannm]

Point should be closed up to about 26° BTDC, open for about 90°, then closed again. Seems something odd is happening with yours if they are in fact opening and closing as you suggest.

Randy is close in his description, but has it backwards; increasing the point gap advances the timing (opens the points sooner in the cycle), closing the gap has the effect of retarding the timing.

I normally set the points at 0.018-0.020", and the coil gap at 0.010". Some folks get very fussy about those settings but in my experience they are not all that critical as long as you are close.

If you are really opening at 8° BTDC and having the close/open cycle you describe, something is wrong with your setting or with the "cam" on the crank shaft. Points should be closed all the way 'round, open for a brief bit to interrupt the current flow, then close again. When the points open and interrupt the current flow, the collapsing magnetic field in the primary winding of the coil induce a voltage in the secondary windings, the "condenser" in effect discharges backwards through the primary windings speeding the collapse of the magnetic field, increasing the voltage induced in the secondary windings.

Check your condenser with your VOM on a high "ohms" scale, switch the leads back and forth a few times; the condenser should read as an open circuit, but will give a little blip on the meter each time you switch the leads as the battery in the meter has in effect charged the condenser a bit.

Finally, keep trying...you may have to prime and pull 3-10 times before you get the mixture in the combustion chamber just right. If after 10 pulls nothing has happened, prime again. After a few cycles like that if nothing happens you better go back to checking the spark, including swapping the plug for one from a running saw. More than one brand new plug has failed to fire under compression for some unknown reason.

Mark

 

[Eccentric]

yep, timing.

Should open just as you say and should be about .018-.021 gap on the points. A little less will advance the timing, a little more retard it. Check the plug gap or even give it a new plug. Whats the compression?

A larger points gap setting advances the timing, as the points will open sooner. A smaller gap setting will retard the timing.

... and that confused me an I wrote it... here's a sketch, if that helps. (sorry so big, no way to resize on AS)

Vic something is wrong here. The points should opn and close ONCE per revolution. Yours seem to be 'fluttering' during the period where they should be staying open. Maybe the rubbing block on the points arm is buggered..

 

[Eccentric]

That's what I get for surfing on my phone. Mark posted the same info as me, but MUCH faster and with greater detail. I had marked the two posts for multiquoting, then did other things while I thought about it. Meanwhile, Mark had already posted. I didn't see his post until after I submitted mine. Al's post was the last one I had seen....

 

[8433jeff]

Its all good. Proves you do know something.:msp_tongue:

 

[HeRoze]

Do most of you set the point at 0.019" nominal at ~BDC and tweak as needed from there? I set the points based on the FW position at the point of open and tweaked to where they just broke at the point shown in that pic.

How critical is the 0.01" coil gap? I used a folded piece of paper that happens to measure at 0.015" (checked last night).

Mark - yes, it is happening as I say - very repeatable. I'll check the condensor for proper current through the inductive load... haven't done that yet and really don't think that is driving this issue (although it may be an issue that comes to light later).

I do have some axial play in the crankshaft.

Anyone have a suggestion on a minimally-adequate compression guage setup... My compression set is of the 1960's automotive variety and the hoses are now cracked and I haven't wanted to spend the coin on a new set. I last used it on an FJ60 I rebuilt.

Lastly - I was tired last night when I posted the pic. I shrunk it down today. vBulletin is the only board I use that doesn't have a HEIGHT= WIDTH= code option. I appologize that my haste to get you info combined with my fatige resulted in a giant pic.

 

[HeRoze]

==26°===

Alright Mark --- you're just showing off now :msp_thumbup:. How did you get the '°' thing? I can't find a way to pick that character and don't see a way to dump an ASCII code in the text, so I am out of guesses.

 

[heimannm]

On my lap top I press the Function (Fn) and Alt key together then type in ku8 (248 if you look at the numbers) and up it pops °. If you want to make 6 In³ press Fn ALT mj79 (0179) on the number keys on the key board, not across the top.

² is Fn Alt kil (253) and µ is Fn Alt klm (230).

Time to head for the airport - SGN-NRT-ORD-CID and finally ALO. Should be home by 2:30 PM Central Daylight Time.

Regards,

Mark

 

[cpr]

I have found the. 010 to be not as critical on points ignitions. Breakerless, though, it makes a big difference.

 

[barneyrb]

I need a little help here, customer brought me a super 60 to get running (was his fathers saw) and I have everything together EXCEPT the starter cover. He lost the screws that hold it on, can someone take some measurements and qty so I can put this bad boy back together? I think they are all 10/24 bugle head but length is a problem. TIA.....

 

[watsonr]

you have the size right at 10/24, can't help with lenght. But most Macs use 1/2, 1 1/8 or 1 1/4 or 1 3/8 for starter covers and 3 or 4 per cover. Might not be much help but maybe a good starting point?

 

[Eccentric]

Its all good. Proves you do know something.:msp_tongue:

Thanks Jeff. Even a blind squirrel finds a nut every now and then.

I need a little help here, customer brought me a super 60 to get running (was his fathers saw) and I have everything together EXCEPT the starter cover. He lost the screws that hold it on, can someone take some measurements and qty so I can put this bad boy back together? I think they are all 10/24 bugle head but length is a problem. TIA.....

Are you talking about a Super Pro 60? If so, there are three 8-32x1-1/8" oval head screws that hold the starter cover to the flywheel cover. There are three 10-24x1/2" pan head screws and three 8-32x2-1/4" oval head screws (called "special screws" in the IPL, without a length given) that hold the flywheel cover/starter assembly to the engine. Certain SP-60 saws had a rivet (rather than a screw) in the hole in the flywheel cover behind the starter handle. Check the IPL's (match the serial numbers) to see which applies.

http://www.smallenginediscount.com/Super_Pro_60_December_73.pdf
http://www.smallenginediscount.com/Super_Pro_60_November_76.pdf

 

[HeRoze]

On my lap top I press the Function (Fn) and Alt key together then type in ku8 (248 if you look at the numbers) and up it pops °. If you want to make 6 In³ press Fn ALT mj79 (0179) on the number keys on the key board, not across the top.

² is Fn Alt kil (253) and µ is Fn Alt klm (230).

Time to head for the airport - SGN-NRT-ORD-CID and finally ALO. Should be home by 2:30 PM Central Daylight Time.

Regards,

Mark

ALT+#### = HTML Code... awesome!

Not sure what the 3 digit ones are, but the the four digit ones are HTML.
So in HTML code ALT-0186 = º, ALT-0176=°, ALT-0179 = ³, ALT-0178 = ², and ALT-0181 = µ.

HTML-ASCII TABLE - hold the ALT key and type in four digits (leading 0)

 

[jerrycmorrow]

I need a little help here, customer brought me a super 60 to get running (was his fathers saw) and I have everything together EXCEPT the starter cover. He lost the screws that hold it on, can someone take some measurements and qty so I can put this bad boy back together? I think they are all 10/24 bugle head but length is a problem. TIA.....

you just need to cut one to length

i measure the depth of the hole either with a probe or by screwing the bolt into the hole and then marking/measuring. then place two nuts on the bolt and snug the nuts together so as to keep them from twisting. place the assembly in my vice and cut the extra off with my hacksaw (usually cut it a couple of threads shorter than measured to allow for a little slack). file the sharp edges off the end. loosen the nuts and take one off at a time. i clean the threads by running the nut up and down several times when it is at the cut end. i do this until i don't feel any resistance between the nut and bolt. then do the same thing with the second nut. just a method i've worked out. works every time.

 

[a. palmer jr.]

That's what I get for surfing on my phone. Mark posted the same info as me, but MUCH faster and with greater detail. I had marked the two posts for multiquoting, then did other things while I thought about it. Meanwhile, Mark had already posted. I didn't see his post until after I submitted mine. Al's post was the last one I had seen....

How many times have I done that? No more than five dozen! Just means that you and Mark agree!

 

[a. palmer jr.]

A larger points gap setting advances the timing, as the points will open sooner. A smaller gap setting will retard the timing.



Vic something is wrong here. The points should opn and close ONCE per revolution. Yours seem to be 'fluttering' during the period where they should be staying open. Maybe the rubbing block on the points arm is buggered..

That looks more like a V8 distributor. Yeah, should be just one on a one cylinder.