PVL IGNITION ADVICE 500 LC

SEM "Seldom Electricity Making"

Have you tried grounding the backing plate? I've read that sometimes a ground wire from the backing plate to a coil mounting bolt can help. Just a thought.

A friend of mine has 2 cr500s that start perfect on the kicker no decomp either both on electrex

I have 2 250s on electrex start them in my trainers .

Don't we need to use non resistor spark plugs with the SEM ignition?

My very first outing with my 83/250/wr/SEM went awesome on the first ride. After washing the bike off the SEM failed. #=#!#=:/=#:+/# made me mad.

The husqvarna chainsaws use the SEM ignition and mine never failed. But we had to re-epoxy other magnets in the customers saws. The original epoxy cracked.

Are You using the same Electrex model on the different Bikes ? With out lighting or with.? I see You have a Maico 490, tried one there ? Are You getting them direct from Electrex or somewhere else?

Reviving this thread again.
I have bought a Chinkychonka Coil and CDI system to my LC500.
Hopefully it will be easy to start because it's a bitch.

Well it looks good. Let us know how it works?

Yeah.
It is at least 10 hp in Bling
I will let you know.

Very interested how it goes, I have several dodgy Moto Splatts!

Electrex World Steve ! Well worth the money.
I have heard good things about some systems made from Chinky bits though. Would I trust it not to kick back ........

I have one on the 420, it is very good however I need half a dozen more! By the way if you are still interested I think I have a set oF 390 cases NOS.

I was the guy who thought up using Chinky bits to overcome the SEM hard starting problem.
My theory was that the SEM wiring gets tired and the CDI trigger voltage goes down over time.
This makes them harder to kick start but can still be bump started with no problem because the flywheel is spinning faster therefore making a higher trigger voltage.

I have made up a ignition test bench and you can see the output voltages at different revs.

The Chinese CDI's use a lower trigger voltage and you can kickstart again.

Having said all that my WR400 is getting hard to start again.

The WR240 is great with no problems.
Had the SEM rebuilt in England only to find that the trigger voltage was too low when it came back and it would not spark under 1500 rpm.
Didn't want to send it back to the same guy who cocked it up to get it fixed so I fitted the Chinese CDI to it and that fixed that problem.

I don't know if the problem is me [ old age , no ligaments in my right knee and damaged quads ] or the WR 400 SEM trigger voltage has dropped too low to work these CDI's.
Still I've extended the WR's starting life over 3 years at a cost of $30 so no complaints.

1982 XC 430 - All bikes are running electrex STK018. Haven't tried one on the Maico 490 its 'mothballed' but if I was racing it again id certainly look into it. A lot of timing, spark and fueling issues on those 81 piston ports engines.

I do seem to remember a very detailed thread some time ago over on OzVmx. I guess that was yours Dukkman A very informative read.

Yes please Steve. Can you give me a ring or text me with a price.

Just got my ChinkyChonkwonka ignition mounted.
Damn, it gives spark an no rpm at all.
Something have happened over the years I guess.

Well.
That worked.

My foot is not happy now.
I had to retard the timing to the max to not break my fot.

This setup gives spark at so low crankspeeds that it will kickback when you turn the engine by hand.

It pulls harder.
Sounds different to.

Good buy.
Except the foot issue

So lets summarize the ChinkYdinkydonk CDI and Coil system.
I bought a slightly different one with a "Racing CDI", whatever that means.

I used the wiring diagram that PEZberg showed us.

The biggest different is that this system gives Spark with the big S.
The old SEM system was always a pain in the ass to start.
Most of the time it didn't ignite at all.

This system ignite at every try, no matter how hard or loose you kick it.
That's the upside.

The downside.
It will backfire like a mule with it's balls in a wise.
I had my ignition set to 2.64mm btdc before but now i have retarded it to 1.5 ish now.

And I can bumpstart it.

Now I have to regain my confident and kick the shit out of it so it doesn't backfire.

i also run my timing around 1.5mm or so...good to hear you have good spark at least! maybe too good??

Okay.
Yes, maybe too good actually.
I know that you could buy a kit for the Hondas that only give spark on the Second revolution when you start it.
Should be almost impossible to backfire then.

hmmm, going to 1.5mm always seems to get rid of the back talk for me..it does hurt and the bike pays a prie for it as well..
at least the bike seems to pull longer with the retarded timing, just not quite as good response out of a tight turn.