PDA

View Full Version : McCulloch chain saw - no spark



Highpower
12-23-2010, 07:56 PM
Any small engine techs lurking about?

I'm looking for ignition coil specs for an Eager Beaver 2.0 saw (points / condensor type ignition).

Not getting any spark. Cleaned up the contacts on the points, condenser seems to be ok, air gap at coil set at .010", points set at .018". Coil primary is 1 ohm and secondary is 9K ohms. Is that too high for the secondary? No shorts to ground.

If I spin the crank with a drill/driver I can get a microscopic spark with a screwdriver (plug wire - to the head) but no where near enough to jump a spark plug gap.

squirrel
12-23-2010, 08:10 PM
It might be the capacitor, those things are prone to failure due the nature of the design. If you have a multimeter with a capacitor checker that would be a start and it might save shot gunning the thing with parts.

The best thing to use for checking a capacitor that is subject to high peaks would be the good old antique Heathkit or Eico capacitor tester with the magic eye tube, that old insturment can actually crank up the volts until the dielectric breaks down. That is something none of the newer testers will do.

Highpower
12-23-2010, 09:39 PM
Got a couple of Fluke meters here that will test capacitance, but without having a good spec on what it should be doesn't help me much. Kind of hard to shotgun it with parts too, since they quit making them years ago. :(

I was hoping a current/former tech might be able to shoot me some specs to help narrow it down. :)

squirrel
12-23-2010, 10:04 PM
Its called stimulate the economy!!! Air out the moldy money and do what washington can't seem to do.

wierdscience
12-23-2010, 10:18 PM
If you don't think it's the condenser,it probably is.

That's the second rule of backyard mechanics.Easy enough to test with any condenser close to the same value.

You might set the air gap at the coil tighter.I use a strip of paper (.0025-.003") to set all mine,the closer the better so long as they don't make contact.

darryl
12-23-2010, 10:33 PM
My first thought was bad cap. Take it out- test for spark again. If it's better, it will probably be good with the right cap in there (a good one). Don't run it without the cap.

Highpower
12-24-2010, 12:57 AM
If you don't think it's the condenser,it probably is.
Quoted for the dang truth! ;)

Still can't find any McCulloch specs online, but I did run across this:
http://www.google.com/url?sa=t&source=web&cd=4&sqi=2&ved=0CDMQFjAD&url=http%3A%2F%2Fassets.fluke.com%2Fappnotes%2Fele ctricalpower%2FB0271b_u.pdf&rct=j&q=how%20to%20test%20magneto%20condenser&ei=KjIUTZ3iHYSglAfgupRJ&usg=AFQjCNGA5eqSZNUlKmlD3cbMNw1PbrMkzA&cad=rja

They are saying the magneto on an outboard uses a .015 - .030 uF condenser, and the one on this saw is reading .202 uF.

Should be close enough to a chain saw (I hope...) so it looks like I'll be taking a $20 gamble on a NOS condenser that's been sitting on a shelf for 20 years now. :mad:

Oh yeah -- also tried it without the condenser. Still no spark.

Abner
12-24-2010, 06:32 AM
Magnets in the flywheel OK?

Flying-Phantom
12-24-2010, 06:45 AM
Check the crank bearings for movement. If it moves you will not be able to set point gap accurately. If I remember correctly that was a common problem.

airsmith282
12-24-2010, 07:02 AM
generaly in a 2 stroker and 4s are not really any different, the coils thats that little gizmo with the spart plug wire on it, thoes will die also more common on 2 strokers , i have never seen points and condensers on 2 strokers must be from the stone age. you can also by pass the shut off switch these some times are flaky and can mess you up to and make you think its something else, the magnuts will never go bad on the fly wheels,
if the fly wheel key is broken or what i all twist snaped it throws off the timming usualy thou it will kick your arm back when trying to start it, a weak spark plug or wronge spark plug will also not allow spark to happen, just the same as not pulling it fast enough on a 2 stroker can also produce no spark.

i have worked on alot of thoes old boys and they can be a pain in the neck.

very difficult to find parts as well as diagrams and specs to

if your going to replace the coil then set it at about 8 thou clearence,to start with,

one other thing you can try is see if the spark plug wire un threds from the coil if it can with out forcing it then try changing it could just be the wire burnt out.. i have seen some coils where you can change the wire hassel free but also thoes that can not be changed at all,

gary350
12-24-2010, 09:01 AM
I got rid of all my 2 cycle gas power stuff. It is all made to sell and it is not made to be fixed.

I had 6 weed eaters it was a full time job just to keep one of them running. I sold them all on craigslist and bought an electric weed eater.

I sold my chain saw too I got tired of fixing it. I bought an electric chain saw it is a little bit slower than the gas one but it does fine for what I do.

I got rid of my riding mower too. I had to work on it all the the time it was a maintenace nitemare.

I have 6 push lawn mowers 3 of them are 30 years old and easy keep runing those old one running.

Everything is throw away these days not made to be fixed.

airsmith282
12-24-2010, 09:48 AM
I got rid of all my 2 cycle gas power stuff. It is all made to sell and it is not made to be fixed.

I had 6 weed eaters it was a full time job just to keep one of them running. I sold them all on craigslist and bought an electric weed eater.

I sold my chain saw too I got tired of fixing it. I bought an electric chain saw it is a little bit slower than the gas one but it does fine for what I do.

I got rid of my riding mower too. I had to work on it all the the time it was a maintenace nitemare.

I have 6 push lawn mowers 3 of them are 30 years old and easy keep runing those old one running.

Everything is throw away these days not made to be fixed.

weed eaters simple fix, use a fule fitler change gas lines every 2 years needed or not, replace carb kits every 2 to 5 years this will depend on use of course and if you leave gas in them and dont use gas stabilizer then you ask for carb problems alot explains alot, also poor choice in brand names will always cause crap to go wornge,
riding lawnmower yup i hear ya there, but use it as a racer project then less problems lol

lawnmowers go for ever it seems and not alot to keep them going ,

2 stroke engines do have there problems, hard on plugs hard on coils and clutchs, carb kits get replaced more often and some of the companys out there like huscrapvarna sorry litt pun there they cant even make decent fule line lol but the saws are great just a bit to costly even for me, ill take a poulan any day of the week..

some tools are better to cheap out on and get more use out of then to spend loads of cash and get nightmares all the time,

homelite is not in the crap catagorey they are having problems making anything decent now and you want the parts that commly blow good luck with that..

of course honda is the curse from hell , paint to work on parts are expensive, so when you get a nasy bill you wounder why you didnt go get a yamaha or something else other then a honda,,

sorry but when you work on this stuff for a living you get to know whats junk whats ok and what will keep you amazingly broke alot, and whats going to treat you nice..

do you buy a BMW or do you get a pontiac , well that depends the bmw is made for hi speeds and level roads then pontiac will go any where

Highpower
12-24-2010, 12:54 PM
Magnets in the flywheel OK?I believe so Abner. They may be a little weak, but still strong enough to stop the crank when turning slowly by hand.

The weird thing is, it will light up a "noid light" type of spark tester just fine - but there isn't enough voltage there to jump a spark plug gap. I'm guessing that the noid light tester is simply picking up the pulse from the primary side of the coil. :confused:

I'm going to try a new condenser and see what happens...

bborr01
12-24-2010, 01:05 PM
How did you clean the points? With emery paper?

If so, you may have some residue in the points.

Open them up and run a piece of white paper through them until it comes out clean, then try it. (a hundred dollar bill works too:D )

I have had similar small engine problems and that was all it was.

Brian

Highpower
12-24-2010, 01:48 PM
How did you clean the points?Craytex polishing wheel followed by cleaning with acetone.

Highpower
12-31-2010, 08:39 PM
Any small engine techs lurking about?

I'm looking for ignition coil specs for an Eager Beaver 2.0 saw (points / condensor type ignition).

Not getting any spark. Cleaned up the contacts on the points, condenser seems to be ok, air gap at coil set at .010", points set at .018". Coil primary is 1 ohm and secondary is 9K ohms. Is that too high for the secondary? No shorts to ground.

If I spin the crank with a drill/driver I can get a microscopic spark with a screwdriver (plug wire - to the head) but no where near enough to jump a spark plug gap.
For future reference if anyone cares: :rolleyes:
Wasn't the flywheel air gap.
Wasn't the cap/condenser.
Wasn't the points.
Wasn't the magnets.

A used coil was gambled on from fleabay and shows 1.4 ohms on the primary and 7.7K ohms on the secondary.
Bu-coup spark at the plug now. Go figure. :mad:

becksmachine
12-31-2010, 09:10 PM
Hurrah, hurrah, good on ya!!

Sometimes depressing how long it takes to get there though. :D

Dave

Highpower
12-31-2010, 09:39 PM
No, what's depressing is not being able to find service specifications on outdated equipment. :(

That would have saved me time AND money. What makes me MAD is the S.O.B.'s that charge $20 for a $3 condenser because they quit making them 30 years ago, and they know they've got you over a barrel! :mad:

I guess I can't complain too much though. The saw only cost me 15 bucks.... :D