Jawa no spark; other electrics work. Rule out...?

I have a 197- Jawa 210 I recently picked up. I was told the engine is good by the guy I bought it from, and the lights and horn work if I pedal like crazy. I cleaned the carb and exhaust, and tossed a new spark plug and coil in, but I don't get any spark at all. Should I worry about the alternator at all, seeing as the lights pop on when I pedal, or could it just be faulty wiring that's doing me in?

The spark plug was gassy when I pulled it back out; just a thin coating, but you could smell it. I assume this is normal when gas is tossed into a non-sparking engine (flooding?), but I figured I'd include the info just to be sure.

Finally, there's a thermistor on this Jawa; it's apparently a bit of a rarity in the field, and a part that's prone to malfunction. Is there a method by which I should test it and anything close to an easy way to replace it if it's broken? What the heck does it do?

Thanks for any and all help!

Jawa no spark; other electrics work. Rule out...?

Sounds like your magneto is fine, if all your electrics work... If it is the thyristor that's gone on you, that might be a chore to find a replacement. You're right about them being rare, but they're fairly simple devices from an electronics standpoint.

There's a British site dedicated to Jawas, <http://www.jawamoped.com">; that has a great deal of information available, especially owners and shop manuals. The shop manual, http://www.jawamoped.com/210WorkshopManual.pdf has the method of checking the thyristor unit on page 23.

The only problem (luckily) I've had with my 210 so far is the clutch, which from what I understand, is the bane of every Jawa owner's existence...

Re: Jawa no spark; other electrics work. Rule out

George Smith /

if it's a 1970-1983 it's not a 210 it's a 207 also it is most likely your thryster let me look thru i may be able to aquire some if not the jawa moped site has a place that sells em, they are pricey but worth it

Re: Jawa no spark; other electrics work. Rule out

evilbrainsponge /

Lemme check the serial number and get back to you; it doesn't look like a 207, but I remember one of the plates on the frame having the build date as 197_, without the number filled in. I'll check for other number plates.

How much would a thyristor be?

Re: Jawa no spark; other electrics work. Rule out

George Smith /

send pics and we will try to identify it to be sure :)

They run 60bucks new from mzb, around 30 used if i was you id break down and buy new

Re: Jawa no spark; other electrics work. Rule out

evilbrainsponge /

Pics forthwith

as soon as I can come across a digital camera.

If description helps, the "thyristor" on my moped looks like a black plastic box with four leads coming out. It's roughly one and a half by two inches in size, maybe a centimeter and a half deep.

http://www.jawamoped.com/210SparePartsBook.pdf

On page 16 of this, it looks like part #1.

Regarding the model, the moped says "babetta" on it in one place and "Jawa" in another, but from what I've read that just means it was built during a weird time between companies. It's too dark out to check, but I'm sure the serial number will help tomorrow. The headlight looks like a 210 round light too, but I suppose the original could've been replaced with one if it is a 207.

On the plus side, apparently the 210 two speeds are a pain in the ass to fix, so maybe I'll get lucky and have a single speed (again assuming I don't just get "lucky" to have a two speed that just doesn't shift out of first :P).

Re: Jawa no spark; other electrics work. Rule out

George Smith /

lol lots of 207s came with round headlights, ive only seen a few with square all in uk and europe except 1 which was imported by a european when he moved here so....yeah that is a typical thryster unit im working on aquiring a used one but no idea if it works but i need it for a project :/ but ill keep eye out if ya want used rather than new :)

Re: Jawa no spark; other electrics work. Rule out

evilbrainsponge /

Ok; I'll order one of those new ones in a bit once I'm sure that's what I need. Is there any easy way of taking a broken one apart to see what makes it tick so I could build one from radioshack parts?

Once the new one is on, is there anything one can do to keep it from dying? Coat the sucker in silicone or something to keep the weather out?

And if you do come across a working, used one on the cheap that you don't have any particular need for, I'd be glad to purchase it off you.

Re: Jawa no spark; other electrics work. Rule out

George Smith /

well to be honest the basics of it are this, It works the same way as a cdi ignition or capacitator discharge ignition, basically it stores power inside a transistor from the magneto coil until the impulse coil tells it to discharge, then it discharges said energy to the coil to create the spark, trouble with jawas is i can get any specs on how much energy it is putting to the coil, and the coil doesn't spark off of a power source, but if ya got the specs on it it is definately possible to build one, I've been working on finding another ignition system that is similar with no luck so far but ya never know.

I'm working on getting a bunch of jawa electronic stuff from various sources, i do have an old one i may replace but it is cracked, it works though think ya can dip it in some of that liquid rubber stuff to give it a good seal :) I'll see if i get this other stuff and get back with ya

Re: Jawa no spark; other electrics work. Rule out

evilbrainsponge /

http://www.btinternet.com/~jhpart/bkns125a.htm

Think this would work at all?

Re: Jawa no spark; other electrics work. Rule out

George Smith /

nope tried it.......for some reason i cant get them to discharge power :/

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