Cdi Unit Restoration For A 87' Vfr 700 F2

[CMR]

Hi,

Has anyone restored one of this cdi's ?

Looking at the capacitors of my cdi,there is only three burned at the bottom of the main board !

[Ghost]

Check this out.

If you know how to manipulate a solder gun, you CAN fix a CDI.

First, ensure you are using leaded solder. not the lead free stuff. Back in the day, they didnt use the lead free. Lead free solder requires about another 80°F temperature to liquify. Today, manufacturers use a different epoxy polymer for their base circuit board material, which can withstand the higher temp... boards from 87 dont.

Start with the capacitors. Keep your board facing down, with the blown capacitor down. Use a pin tip. keep it clean too, wet it often. Gently pull the capacitor as you resoften the solder. Do this for each, and you can easily pull them out. Replace them in a reverse order... again, load from the bottom.

If your unit continues to not work properly, start at the fuse break, and work your way out from main power. Check all ground connections and ensure they are properly fitted.

Similarly to the visual indication of the capacitor, your resistors will have a cracked or brownish look to them. Radio shack will have replacements. Ensure you replace same rating capacitors and resistors... I know this probably didnt need saying, but... meh.

there is a power diode on board too, be sure you Ohm this, and ensure it is also not faulty.

My guess would be that if you blew caps, you probably have a closed short somewhere. course ... unless its in an open area, where you can get a 1/16inch drill bit in there to re-break the connection and subsequently re-epoxy it, this is a non-recoverable failure.

I would recommend keeping a 12V battery close by, and occasionally connect it after each part replacement, and check for a general power to ground cross check to your electrical print. if you get a full pass, then move to Ohming each set of resistors. If you are fortunate enough to successfully repair the CDI, I recommend not running over 7,000 RPMS until you determine what cause the caps to blow in the first place.

Similarly, if you are able to ride the bike, please keep close to home for a while until you are confident your work will hold.


(All that said, I would prefer to simply buy one from eBay)

Good luck, Let us know how you do?

[TOE CUTTER]

If you repair it and get it working again post pictures....keep me posted regardless please. I have not had one of these fail for a very long time and when I needed one last they really did grow on trees.I know that is not the case now so please let me know how it turns out.

[CMR]

I'll do !

Very helpful comments Ghost,I have located one of those in about 180 $ but that's in case my fix didn't work out !

[CMR]

you bet !

regards..

[CMR]

Guys,the fix works and I have spark again,so the costs were:

60 cents for the capacitors.

8 pack of beer for a friend (electronic tech.)

toe cutter,here the pics ,the ones switched are those in the bottom of the main board!

Ghost[/b],thanks for the comments !

regards..

[crustyrider]

this is the little black box under the seat right?

[CMR]

Yep !

I was dealing w/o no spark but know Ihave !

[volks6000]

were those from raido shack............ what the resistance on those. I see gold , orange, purple is the top one brown??????

[CMR]

Don't know !

I've just get the pack of beers!

[Ghost]

Originally Posted by volks6000

were those from raido shack............ what the resistance on those. I see gold , orange, purple is the top one brown??????

In order from left to right, they are;

12mOhms +/-5%

68KOhms +/-5%

.96 ohms +/-10%

I really like this site.

Identify your Resistors


The thing to keep in mind for resistors is… they don’t have to be put in a certain direction. So, for example the second one CMR put in is backwards if you go look it up.

When replacing resistors, if you have ANY doubt of the resistance, (cause it makes a huge difference), just take the unit with the bad resistors to radio shack, and point to the ones you want replaced. Some locations will do the work for you for a small fee, like $15.00. As CMR has demonstrated, a few $0.60 resistors can save you $180.00 so, paying the $15.00 fee is a no brainer, (so long as you know that’s your problem).

Good job CMR. You are most welcome. The beer is a nice touch. Truthfully, a little alcohol will steady your hands when soldering… a little. Lol.

[CMR]

Thanks for the link !

regards..