modified cdi and cr 80 coil

flatsteve51 said:
Can any body tell me where to find 760 ohm resistors. It's the only part I can't find. Would a 750 ohm work? Thanks for all the info I'm looking forward to building this
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The 750 would most likely work, but you can put two resistors in series that add up to 760 ohms. also you can measure the 750 ohm ones until you find one that is close to 760 ohms.

Remember the value is plus or minus 750 ohms based on the tolerance of the resistor. So if you have a 750 1/2w +-5% resistor it could be as low as 712.5 ohms or as high as 787.5 ohms.
 
brnot I have replaced my spark plug wire at advanced auto parts store. Made hide difference. More power. Better stars and using original Cdi. Along with speed carb and expansion chamber exhaust. It runs like a dream. It's a 80cc schwinn. 28 inch tires. For a road bike it runs great. But yes just replace the wire and u will notice huge difference. Got a 38 tooth sprocket and high performance racing head for more compression on way and my performance upgrades will be done. Can't wait. Should go around 45 mph after that.
 
ivan H said:
Hey guys, if u read thru this thread & the thread about adjustable timing magnets u will find several warning on the dangers of running to much advance. These warnings r 4 good reason, u can easily hole a piston top, do big & small end bearing damage etc by having the spark too advanced. In this & the "roll ur own CDI" thread I have given a couple of ways to know if the spark is detrimentally advanced, but if u r running advanced spark & r unsure u should pull the jug & piston & view the underside of the piston crown. If all is ok it'll be the normal alloy color with an oil coating. If however, it shows black carbon deposits on the underside of the crown, u r running too much advance. The black carbon deposited is burnt oil resulting from excessive heat. Back the timing off. It doesnt take long to pull the jug & piston to check & is much better than replacing ur engine. Have fun. Cheers
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Holes like this....

:-||
I had the 27 resistor jumped along with the 100 (which i overlooked because i thought it was the 390)
It was a BRAND NEW piston. maybe 10 miles total, with a small head gasket leak so compression wasn't even as high as it could be.

This situation had nothing to do with the cdi that Dracothered has graciously shared with us, but more so my own error in jumping choices. But with that said, Ivan H sent me some schematics that will hopefully prevent errors like this from happening. Ill be putting them up once i get it drawn up on the computer.
 
Sorry to see you had a melt down there. Yes if you build this CDI make sure all your parts are the right ones and set it to a stock JAG setting at first then go from there.

JP4 & JP5 in the "A" position.
 
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dracothered said:
Circuit diagram
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Here is the Board Layout from the parts side.

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Foil side of the board

attachment.php
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Maybe we can all get together and do a group buy and have some blank PCBs professionally made by a board house?
 
whipaway said:
Maybe we can all get together and do a group buy and have some blank PCBs professionally made by a board house?
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I took the advice of Ivan H and lined everything up in vertical series on a solderable pcb board then ground off the non-needed areas with a dremel (to insure no shorting would happen). Worked great for me! ill try to get a pic of it for you.
 
Toadmund said:
Can I substitute with this SCR?
HERE

And is there any reason why I can't use switches instead of jumpers?
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As far as the SCR I am not 100% sure, but it should work just fine. Now about using switches in the place of jumpers that would be just fine as long as they aren't small low current switches.

NOTE: DO NOT CHANGE THE SETTINGS WHILE THE ENGINE IS RUNNING, THIS MAY CAUSE DAMAGE AT THE TIME OF FLIPPING THE SWITCH SETTING.
 
whipaway said:
That part, BT136-600E is a TRIAC, what you need to use is a(n) SCR.
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But it's both!

(10 Pcs T0-220 Package Phase Control SCR Triacs 600V 4A)

So.......I ordered the wrong thing, I won't cry....th-th-this time.

Going to have to do some info digging I guess.

Your Right
TRIACs belong to the thyristor family and are closely related to Silicon-controlled rectifiers (SCR). However, unlike SCRs, which are unidirectional devices (i.e. can conduct current only in one direction), TRIACs are bidirectional and so current can flow through them in either direction. Another difference from SCRs is that TRIACs can be triggered by either a positive or a negative current applied to its gate electrode, whereas SCRs can be triggered only by currents going into the gate. In order to create a triggering current, a positive or negative voltage has to be applied to the gate with respect to the MT1 terminal (otherwise known as A1).
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So the question is, can I put in a diode?
 
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hotrod0198 said:
i have a 48cc skyhawk motor and my magneto and the bolt it is on broke and i dont know how to fix it
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I suggest you make your own post with your problem under the 2 stroke section. More members are going to see your post. Furthermore, your topic is not related to the ongoing post.

Good Luck,

Chris
AKA: BigBlue
 
mountain80 said:
Can I ask what the difference is on what the original Jag and the modified cdi does?? Not very electronic savvy lol.
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You have a little more adjust ability with the modified CDI and the JAG seems to be a little over priced from what I hear you get from the maker of it.
 
ok i have the jag unit and it crapped out after a couple of days.It took to long to get it and Living in Canada would have to ship it back etc and it is now spring. Can you fully expalain the more adjustability of the modified cdi? I see that the jag has 2 different jumpers for the advance and retard curves so 3 curves each. but this one has only 1jumper for retard curves. I am trying to maybe order the parts and get someone to help me with building one as my motorized bicycle has cooked a few cylimders with the stock one due to compression and modding etc. Thanks for any info provided.
 
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