problems with old McCulloch ignition points?

[Jeff Campbell]

Rob - the tarnish on some of these points I have is so heavy, that solvents on a piece of card stock will not clean them, I still get no continuity or the points are unpredictable (flaky) cause they are still tarnished. I've tried lots of solvents: methanol, acetone, mineral spirits, lacquer thinner, chlorinated brake cleaner, non-chlorinated brake cleaner, goo-be-gone .... You must have some of the better preserved points - keep them!

Tom - the cheap finger nail remover is 100% Acetone (the premium stuff has gunk in it for nails that you wouldn't want on your points). It's a cheap way to buy small bottle of acetone.

Mc Bob - the only problem with eliminating the points by using solid state devices, is that there is no way of knowing what your timing is, using it on a kart motor, will the engine overheat or will it under-perform? There is no way to tell.

Jeff

[mcbob]

Maybe some-one should give it a test out so an answer is available surely one of the fellas has a spare engine that could be used in a test along with a bit of monitoring ya never know unless ya have a go they work great in my hotsaws as now i have them as standard equip on all of them and will be running them on my dual Bender which i'm working on now.

I know some wouldn't want to try them as their not standard Mac stuff but i like the fact that there set and forget type of stuff except for keeping an eye on the airgap there's nothing else except a kill switch wire and kill switch.

Mc Bob.

[david a luciani]

An excellent point about the tarnish jeff.
i hadn't considered that and tarnish is the enemy of conductivity.
it's such a good idea that i'm gonna try it on my coffee cup of old points that looked good but didn't work.
they all looked good but didn't produce a decent spark.
dave
p.s. that's an old jewelers trick for cleaning silver chains.
i'd forgotten that one .
dave

[Tom Smith]

Jeff, checking solid state ignition timing is not all that much trouble. Indicate a TDC mark on the flywheel with a Sharpie etc. then mark 10, 20, and 30 degrees on the inner cover. Spin the motor with the plug removed with a starter or anything else that will do, I use the pulley on a belt sander. Use a standard automotive strobe timing light and that's about it. McBob is correct, not much to it besides the flywheel air gap although the air gap and plug electrode gap are more critical with solid state than with points. McBob, the PVL 820 units work real good.
Stihl started using electronic ignition in 1967, what's new?

[Rob Voska]

Don't forget there are different curves in the electronic modules.

[mcbob]

Don't forget there are different curves in the electronic modules.

Yes they are proberly different i'm not certain what the curves are i know Steve O'Hara asked me that many months ago but i don't have that type of test equipment nor the expertice to find out but they work for me in my hotsaws.

When i enquired about the unit cost of the PVL i neally fell off my chair, the Ryobi units i get for nix at the recyclers so i took the punt i have also set them up on my Westbend 820"s.

Mc Bob

[Jeff Campbell]

Tom,
I've heard of checking the timing with a strobe, but could you clarify how the timing can be adjusted (are you changing the coil lamination to flywheel gap?).

Everyone,
I just put the ignition system together on my MC5 project motor, using the points I cleaned in a cup of salt, baking soda, hot water and aluminum foil. I put in a new Phelon condensor. I also used a NOS McCulloch coil replacement kit (a generic kit to replace the coil on your lamination assembly). I used the coil kit to get the extra plug wire length for the MC5. The spark on this thing is UNREAL, I'm cranking it by hand, snapping my wrist to bring the flywheel magnets past the coil ... the plug boot isn't on yet, so I can hold the wire at any gap to the block .... I can easily get a bright thick blue spark up to 3/8" long!!!

MC5-spark2.wmv

Ignition spark strength test - MC5 project video segment

(880.51 KiB) Downloaded 1240 times

Jeff

FYI - I just changed some settings so we can upload many different types of files as attachments, such as this video.