ignition chip

[joeymt33]

I tried posting this in the mcculloch page since i'm working on macs, but i'll try to get a response here.

I've got a question about installing a ignition chip on mcculloch saws. I currently only have one on a SP80 and a SP81, I really like the way it runs. I've tried unsuccessfully to install one on a SP105 and today I couldn't get one to work on a PM60. There are two ways to install, positive ground and negative ground. How do I know what type Of ground is on the saw?

More info: on both failed attempts the saw would run good for about 30 secs then no spark at all. The chip will not work again after that.

 

[slipknot]

i assume you are talking about an electronic ignition module to replace the points? I always thought of ignition chips being some kind of upgrade for an import car or something to that effect...otherwise i have no idea what you are talking about.

 

[joeymt33]

yes, it is a ignition module to replace the points. thanks for responding. the instructions show two different wiring diagrams for a negative ground or a positive ground. On my SP80 and SP81 I wired like it has a negative ground and they run great and have for many hours of use. but a couple months ago I though i'd try one on a SP105 and it ran for about 30 seconds and the module was shot. well, a couple days ago i tried to set one up on my pro mac 60 and got the same results as the SP105.

 

[Little Al]

yes, it is a ignition module to replace the points. thanks for responding. the instructions show two different wiring diagrams for a negative ground or a positive ground. On my SP80 and SP81 I wired like it has a negative ground and they run great and have for many hours of use. but a couple months ago I though i'd try one on a SP105 and it ran for about 30 seconds and the module was shot. well, a couple days ago i tried to set one up on my pro mac 60 and got the same results as the SP105.

There have been posts before that have said that they have had trouble with point replacement chips fitted to mac saws although I can not remember which model it was that had problems, some Stihl`s also seem to have problems I think in their case you have to alter the timing Maybe you could find out more from older threads via the search

 

[joeymt33]

i may go to NAPA and get another brand to try. i'll post my results so others looking for this info may be helped

 

[OREGONLOGGER]

I use the Yellow Atom module no timing or carb adjustments on my Mac's. Older Mac's (There all old) with points and condensor I remove the condensor and solder a WIMA 630v 0.22uf @ 10% chip in place..My old Mac's run like new after this app...good luck!!

 

[joeymt33]

Update

I found out what was frying the ignition modules. I had them mounted about two inches from the coil pack and I'm guessing that was the problem. I fried 3 modules like this. I tried moving the module about six inches from the coil pack and it works great. I didn't change any wiring or ground position. My mistake cost me some cash, but for you guys it may save you some.

 

[heimannm]

That is interesting, you have to wonder why the MFG does not make a note of it in their instructions, unless they really want to sell a lot of the modules to the unsuspecting buyer.

I have a few of the point replacement modules on hand, but I have not yet resorted to using them on any saws I have. I find with proper adjustment the points and condenser work just fine for me.

Mark

 

[joeymt33]

That is interesting, you have to wonder why the MFG does not make a note of it in their instructions, unless they really want to sell a lot of the modules to the unsuspecting buyer.

I have a few of the point replacement modules on hand, but I have not yet resorted to using them on any saws I have. I find with proper adjustment the points and condenser work just fine for me.

Mark

you're right about the points, i will not go back and replace the new points that i installed on restored saws, but i can buy the module local and when i don't have a set of points its a great replacement and it is discrete. i usually have to wait a week to get some points in.

I have noticed that these modules will produce a hotter spark at a low rpm than points. in my experience a points set up gives a hotter spark at low rpm than a OEM mcculloch electronic ignition. its like have the best of the two, hot spark at low rpm and a more precise ignition at high rpm. is there a "seat of the pants feel" after the install. problably not, if i think so, it may be all in my head.

 

[StihlNAlberta]

I use the Yellow Atom module no timing or carb adjustments on my Mac's. Older Mac's (There all old) with points and condensor I remove the condensor and solder a WIMA 630v 0.22uf @ 10% chip in place..My old Mac's run like new after this app...good luck!!

You would happen to have a part number on this yellow atom module would you? I'm trying to revive a 740 and now I have the carb done I'm thinking it may be ignition. On the silver chips ..... Do you need to change the timing?? I'll post a pic of the 740. Hopefully not an air leak

 

[StihlNAlberta]

Here is the module. Saw runs but is not smooth and idles all over the map, but then when it does find a spot it likes it will idle fine. Bit of a miss but even with carb adjustments. Though time idling down sometimes

 

[Little Al]

That is interesting, you have to wonder why the MFG does not make a note of it in their instructions, unless they really want to sell a lot of the modules to the unsuspecting buyer.

I have a few of the point replacement modules on hand, but I have not yet resorted to using them on any saws I have. I find with proper adjustment the points and condenser work just fine for me.

Mark

Not strictly Mac, only but was "advised " by the rep selling NOVA chips to mount them alloy side towards the source of heat

 

[Okie]

I tried posting this in the mcculloch page since i'm working on macs, but i'll try to get a response here.

I've got a question about installing a ignition chip on mcculloch saws. I currently only have one on a SP80 and a SP81, I really like the way it runs. I've tried unsuccessfully to install one on a SP105 and today I couldn't get one to work on a PM60. There are two ways to install, positive ground and negative ground. How do I know what type Of ground is on the saw?

More info: on both failed attempts the saw would run good for about 30 secs then no spark at all. The chip will not work again after that.

I had about same experience as you only worse trying to use the Nova II chips on the McCulloch 1-43 and 1-50 series of saws.
Reason I was trying the chip was I have a McCulloch 1-43 and points went bad and when I installed the new set of McCulloch OEM points and set them at spec of .020 they would not close good due to about .005 of the point crank lobe being worn off due to rust from not being used. (crank bearing was ok with no slack)
I set them on .015 and it ran good so I thought I would just convert to electronic chip and make it modern, but I was already skeptical because being a electronic tech I had tried generic conversions instead of OEM on auto's and get erratic failures.
First one I carefully installed on a 1-43 and it started and ran great using neg ground. I took the saw to the woodlot with my stihl 028 (the 028 has 30 years old points ign) and used the heavy old McCulloch for about 15 min doing great and starting easy. I was a happy wood cutter and proud of myself and the old saw and I had a spare chip. Next day it briefly started and died, no ignition fire. I installed the other Nova II chip and no go, had fire but would not start and severe kickback of the pull rope like out of time. One guy indicated he removed his flywheel key and moved the flywheel to get electronic chip timing correct, using no key.
I reversed the polarity to pos and it started, but was about to break the pull rope due to timing off and idling poor. Both chips were new in OEM sealed packages with same part numbers, one ran great for awhile, the other kinda wanted pos ground. That told me all I need to know about attempting the convert.
I reconnected the new points and contacted the seller for a refund (they indicated that they had mixed results with the conversions and had some returns and were going to stop selling the chips and to throw the bad ones in the trash can and they did the refund. I asked the USA seller if they were Nova clones or real ones and they indicated they were Rotary real deals and the package box indicated Rotary brand) and I chalked it up to more piss poor experience with non-OEM electronic engine converts. I think my post was over in the McCulloch forums of this site about 6 mos ago.
I asked on this forum about converting to electronic chips in old saws and got weak replies and finally mixed results.
Seemed that using OEM conversions like for Stihl, etc was best method for reliability.
The chips were heat sinked good, etc.

I had prev asked about whether to use pos or neg ground and response was it pertains to the direction of flywheel rotation.
So connect for neg ground first and if no go reverse polarity. (some chips the polarity cannot be reversed, fixed at neg ground.

I found a pile of New Old Stock (OEM) McCulloch points and condensers on flea bay in the OEM packages dirt cheap so I stocked up. I have old chainsaws with points ignition that are 50 years old and doing great.
I won't convert my old points type 028 stihl to OEM electronic unless maybe the magneto coil goes bad. (it will get new points, when points last over 30 years with no problems that's good enough for me.

 

[Okie]

added because could not edit into the above post at later time:

The Nova chips that I was testing in the above post is part number 31-8786.

The instructions read not for use with 12v ignitions or flywheels with multiple magnets.
A electronic ignition type coil might be required for proper ignition because some points type coils may not produce enough spark for good ignition.

 

[Greg Gauntner]

glad i saw your post as i was gonna try the electroni chip in my 1-76 but doesnt look good for that BUT... would an oem chip work or are there timing issues?

 

[Greg Gauntner]

Can i even get one for my 1962 saw?

 

[heimannm]

Did you see Joey's comments about where to locate the chip? Keeping it away from the coil seems to make big difference on the long term reliability of the electronics.

That said, I would always favor points since you can easily troubleshoot each component if there is ever a problem. Of course if the points cam is particularly worn the chip may be the only option.

Mark

 

[Okie]

glad i saw your post as i was gonna try the electroni chip in my 1-76 but doesnt look good for that BUT... would an oem chip work or are there timing issues?

What is a OEM chip for a 1-76.
There will be timing issues.

I'm not familiar with a 1-76.
I was trying the chips in the 1-40, 1-50 series of Mac's and was really surprised at how good the first test appeared. Saw started right up, ran good. Only ran it about 30 minutes on and off in a test log doing test cutting. Next morning the saw would not start. Installed a same type spare chip and no start, no fire. Reversed the polarity (the chips I purchased were the reverseable polarity type) and finally got a start but out of time, Not running good.
The chip was mounted proper, heat sinked good and all precautions. I'm also a electronic tech.
It has been my experience that most generally a generic add on electronic ignition
systems are not reliable. I don't even try such unless as Mark Heinmann says points/condenser systems are worn beyond repair or the parts no longer available.

I recommend that you stay with your existing ignition system.
I can do some careful shopping and do saved searches on flea bay and still find new vintage ignition parts and some within reasonable prices for old Mac's..

I went back to my 40 plus year old points/condenser system for reliability.

 

[pioneerguy600]

My understanding on the work ability of these chips depends on the orientation of the two magnets in the flywheel. There is a North and South pole magnet that can be arranged in either sequence, North first reaching the coil followed by the South, on other saws/machines it could be the South first followed by the North, the grounding of the chip depends on this sequence. My take is that the negative ground is used for the North before South orientation.

 

[Okie]

My understanding on the work ability of these chips depends on the orientation of the two magnets in the flywheel. There is a North and South pole magnet that can be arranged in either sequence, North first reaching the coil followed by the South, on other saws/machines it could be the South first followed by the North, the grounding of the chip depends on this sequence. My take is that the negative ground is used for the North before South orientation.

Right: The two exact same model number Nova chips I was testing had provisions for polarity reversal. The first one that ran good and failed soon afterwards ran on Pos polarity in the Mac.
After it failed I installed the second one and it would not start on on Pos polarity.
Just for drill I connected it neg polarity and got fire and severe kickback when trying to start the saw. When it finally started it was out of time and not running good. Two NEW chips with same model number with different results. That was enough testing for me. The seller when contacted about the results did a refund and said throw them in the trash and indicated they were quitting selling the chips due to complaints. I've heard of some guys that think they are great but I have never witnessed such and are not reliable enough for me.

Only thing I seen that is nice about them is they are easily installed for testing.
(do not have to pull the flywheel)