so i have this jawa a buddy gave me, and after some work it runs but not good. needs timing done and idk how to do it on this, or if this setup is even correct. please point me in the right direction


Re: jawa

How many miles, mine has like 40 +/- ...

this is what mine looked like. aahahaha

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Re: jawa

Re: jawa

Christian, your stator is missing a coil. Could be causing weak spark. you can get one at eastern two stroke on ebay. search jawa moped

Re: jawa

The only timing adjustment for these is the rotation of the stator. You will have a few mm of rotation each way when you loosen the stator screws. That missing coil might be lighting so it may run as is. Do you get spark?

Re: jawa

yeah it has spark and runs but doent idle well or go uphill or have any real power. whats this thyristor and tranzimo stuff? cus i dont think i have that. i know its missing a coil but i read somewhere if you dont have a thyristor you only want 3...?

Re: jawa

Vlado vlado /

go to www.jawamoped.com

read and learn, plenty of correct informations

Re: jawa

timing check with a timing light, line up stator, want firing ~15-20 deg btdc

turn stator to adjust, super easy since the magneto is inner

Re: jawa

kim jensen /

You have the thyristor, the little black box. Read up on bow to test it, but if it runs, you are probably OK. Jawas have several lighting coils, you may be fine without one of the smaller ones. Check timing and clean carb and jet. Should be Better.

what am i missing?

so i now know i have the newer black bow thyristor, and the bike i have is a 77 so it originally had the red tranzimo unit. after researching the conversion i saw that i am missing the metal can external ignition coil? cold this be the main contributor to my super weak spark?

also i dont know how to tell if the person before me swapped the stator ring. is this completely necessary?

and lastly, provided i have(or get) the correct stator ring and get the external ignition coil, do i still need to get the 4th coil for the stator? or can i make it run correctly without?

thanks for all the help guys

Re: jawa

the black box oughta have the internal ht coil, if the plug wire plugs into it, then it doesnt need the big ext coil

stator ring oughta be fine

4th coil is lighting, totally separate from ignition and pretty much unecessary.

Re: jawa

I did a ignition swap on a 77 with the red brick setup to the newer style with the can ht coil. The harness had to be rewired as well they are quite different. I think the old style had a 3 prong black box and newer had 4 prongs. Not to be confused with the modern upgraded black box that includes the ht coil.

Re: jawa

Double Trouble Dan /

Since your bike is running , i would concentrate your efforts on the carburetor.

The air flow on those bikes is awful and if you don't have the proper filter , the bike will barely run.

Your jet is probably clogged . Try this.

Run the bike with the choke slightly(1/4) closed. if that is better, the carb is dirty. Not getting enough fuel.

I would also put a brand new spark plug in just for kicks.


Re: jawa

i am 100% sure its not the carb. been cleaned 15 times. i have the proper stock airbox setup too. new plug/boot/wire was the first ting i did. everything else is good, has compression, just low power output

Re: jawa

The top speed on that model is around 20. To make it fast you will need a full carb intake pipe upgrade. I put all that on a 210 and top speed was 35. Had the homemade thyristor. Bitutbo ,14 puch intake and 15.15 sha.

I'd find a newer bottom end with a single spring clutch and the harness plus electronics. Then use a slanted port top end and delete the decomp with a different head or plug it. Then the carb intake pipe party. that should get you to 35.

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