Stihl 07 electronic ignition

[880]

Hey fellas, I am having points and/or condenser troubles with one of my 07's.
I have a atom computer ignition here, and want to put it on, but I was told once, that if the flywheel has more than one magnet, it will not work, my flywheel has four, can anyone confirm this, and if so, is there any other way to make the old girl electronic? cheers TL

 

[Rustynutz]

Unless you got a four cylinder chainsaw there's only one! the other's are just counterbalance weights

What module you got single pin or double? cpm-00 or cpm-01?
I just fitted the 00 to my mcculloch 140 brilliant it works so well now wish I'd done it years ago.

you will need to bolt it to the crank case somewhere with plenty of airflow as they get quite warm, and as it's only one bolt use treadlocker on the stud.

 

[Rustynutz]

You can just connect it up and spin the flywheel by hand to test it before fitting just in case you have an oddball flywheel....

 

[Rustynutz]

Found this in the tinternet....

This is a very good condition Stihl 07 that is still a very useful saw. It has the points eliminator and starts. and runs like new. ...
www.bigdmc.com/stihl07.html

So it looks like you can fit a EIM


Hope this helps?

 

[880]

Thanks mate, real handy info, how do you tell which one is the magnet, they all stick to the screwdriver fairly well? I do not know weather it is single pin, all this stuff is fairly new to me, as I only just started collecting vintage stuff, but it only has a earth wire, and another lead, which I presume goes to the magneto, then back to the stopper button?

 

[Rustynutz]

Its the wire that go's back to the switch coil you need to connect to it.

I'm a bit concerned if this will work on your machine?? sounds like you have a different system to the norm? I'm sure someone will chip in on this.

From reading up seem's not compatible with multiple magnet magneto systems
you might have to live with points??? boo hoo!

 

[880]

I took the old points and condenser out, and wired the thing up, didn't worry about solder or stop switch at this stage, chucked the fly wheel back on, and the starter housing, and let rip, fired up instantly.
It is late here, so i'll do more tomorrow, I have the exhaust off it too, so can't really tell you how it runs, apart from it is f'en loud. Anyway after twenty odd years in pieces, collecting dust, my 10 dollar purchase is looking promising

 

[Rustynutz]

Good on you!!!
let us know how you get on in the morning

 

[880]

Well, here's a quick update, I spent most of this afternoon in at the local dealer, going through mountains of old saws to get the missing bolts, crank nut, and other various bits, wired the old girl up properly, slammed a nice old retro 25" Duromatic on, as well as 80 drives of 404, two pulls, and she fired to life, idles brilliant now, and revs up and down spot on, I haven't used it under load, yet, and this may tell me if the timing is off, but it will do as it is, just for an old vintage girl. Cheers TL

 

[Rustynutz]

Glad to here there's life in the old girl!

as with timing on these electronic jobbies its got two options, working or not!
look's like you got the working option, you should get improved performance as your new ignition is now advancing and retarding the firing position based on engine RPM like proper engines do!

you might have to tweak the carb now because the engines running so much better it will require less fuel...

if it's anything like the 140 I did it will blow you away! just like having a brand new saw again...
:greenchainsaw:

"Happy Cutting!!!"
Russ...

 

[880]

Thanks for your help Rustynutz :biggrinbounce2:

 

[daedna]

part #/info needed....please

Hey guys,

I'm currently rebuilding an 07s also. I replaced the points and condensor with a Mega-Fire ignition module part#440-065 and although I am getting good spark, the saw will not run. It fires and backfires occasionally, has a rebuilt carb, good compression, impulse port is clear, muffler is clear, new fuel filter.

Is it possible the mega-fire won't work with the 4 magnets and the atom does?

Do you have the part number, or any other info on the module?

Thanks a bunch!!

 

[Rustynutz]

Don't know much about Mega-fire seems mostly used on lager engines with battery ballast etc.

On searching found this....
I have Used the Mega-Fire, but dont Recommend them. They Work well on some Mowers and Give Problems on Other Mowers. Its a Coil Thing. The Only Ignition Module I have Used with Constant Success is the Made by Nova.

and having good feedback and personal success with the Nova / Atom I tend to agree with him...

 

[cbfarmall]

Don't know about your problems in particular but watch the polarity. You can flip the ground and ignition wires on these modules and the saw will run but very poorly. Found this out with my Mac 550.

Chris B.

 

[Rustynutz]

Found this on another site talking about the Mega-fire,
wonder if this is why it's backfiring ???


Below is the information on the Electronic Ignition unit.

Electronic Ignition Unit Replaces Points and Condenser: Fires small engine spark plug 5 to 14 times with each impulse. Fits most 2 and 4-cycle, air-cooled engines. Maintenance-free. About the size of a quarter.


as far as I can tell Nova/Atom units only fire once per rev as points did.

 

[daedna]

Thanks

Thanks for the help guys.

I tried both polarities prior to posting, so I guess I will buy one of the atom modules. I'll post the results in a week or so after I get it installed.

 

[880]

I thought I better give you blokes another update...
I thought I would try the old girl out this morning on a log in my log yard, to see how the old clunker performed... Well, the first 5 minutes it was really unbelievable, in power, and smoothness, I can say it had the cutting speed of about a MS 380, which is pretty awesome, giving the thing revs slow, and the fact it's old.
Then it started firing everywhere, and then not at all, which I was half expecting, due to the fact, old mate at the chain saw shop, told me it wouldn't work, hehe... I thought I finally proved the old coot wrong on something
He says, that due to the flywheel having 4 magnets, and the magnets being so close together, doesn't allow the flywheel to fully demagnetise enough, for the electronic chip to work properly, fine with points, of course, but not a computer, so in short, I reckon I've cooked the chip.
I can't be stuffed, friggin' around with it anymore, but least I know the motor is really good, so I ordered a new set of points, and condenser, so the old girl will go back to original, which is still cool, considering, I didn't think it would ever go... anyway there you have it, cheers TL

 

[Rustynutz]

Its the wire that go's back to the switch coil you need to connect to it.

I'm a bit concerned if this will work on your machine?? sounds like you have a different system to the norm? I'm sure someone will chip in on this.

From reading up seem's not compatible with multiple magnet magneto systems
you might have to live with points??? boo hoo!

Yea looks like a problem! the thing I've seen is called a points eliminator, I think its one of these
http://cgi.ebay.co.uk/Electronic-Ig...arParts_SM&hash=item1c100f62ca#ht_4185wt_1102

for a single cylinder engine though,
never mind! new set of points and condenser will work perfectly well