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Discussion Starter #1 (Edited)
Ok Im tired of seeing my bike sit in my storage building. 4 years ago I asked for help to a rear cylinder right spark plug not firing and since I had back issues and other medical issues thats made me put my bike on the back burner and now Im working on it once again. I bought a old Kawasaki analog multimeter for a killer price and now tested my CDI and it fails every test per Clymer manual page 306 it actually doesn't even show any resistance on my multimeter except for testing pin 1 and pin 6 together I get a reading but its still slightly high and I bought a new analog multimeter non Kawasaki and it still fails to show any resistance except for the same pin 1 and pin 6 together test with that said Im going to buy different CDI here soon but does anyone know how to test the transisters inside my broken CDI. If anyone has knowledge on how to repair the CDI please let me know I love working on this kind of stuff. Thanks in advance ride safe my fellow riders.
 

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I know nothing about the CDI or it's testing.

Here's a couple of links that might help you, one for transistors, one for resistors. I could never get resistors right because I'm color blind enough to misread the color stripes.

Transistor testing:
http://www.wikihow.com/Test-a-Transistor

Resistor testing:
http://www.wikihow.com/Test-Resistors

A couple of our electronic techs have gone missing, but I think some are still posting.
 

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PM member Mercury...he's up on that stuff because he's "a 'lectical engineer".... :D

Generally though, with CDIs, if they go, they GO....no warnings...if the case looks puffed out, more than likely a cap blew...if you cant find a used replacement, just get new...prices have gone way down and some are interchangable (like rectifiers)...
 

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No...the R/R is the rectifier (used to be called selenium rectifiers in the old days) manages voltage...the CDI unit ( Capacitive Discharge Ignition) generally replaces the standard coil and points type. After awhile, the capacitors on the circuit board get overheated and blow (swell) rendering them useless. Most of the cases are sealed, and really, not worth trying to split open and repair...most are under $100 new now.

Know how you have an ignitor button on your BBQ that causes spark to ignite the propane ?...thats a mini capacitive discharge...a CDI unit does this, and also manages the spark.
 

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No...the R/R is the rectifier (used to be called selenium rectifiers in the old days) manages voltage...the CDI unit ( Capacitive Discharge Ignition) generally replaces the standard coil and points type. After awhile, the capacitors on the circuit board get overheated and blow (swell) rendering them useless. Most of the cases are sealed, and really, not worth trying to split open and repair...most are under $100 new now.

Know how you have an ignitor button on your BBQ that causes spark to ignite the propane ?...thats a mini capacitive discharge...a CDI unit does this, and also manages the spark.
Ah, ok. I already knew what the R/R is. Just thought someone was calling it something else.
 

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Discussion Starter #7
Yea the case isnt puffed out of nothing its sucks since my bike is a 2005 with like 3k miles on it. Ill have to look for a low priced new one if I can find one low enough or Ill just buy used thanks Wolfe your advise is always welcomed.
 

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Discussion Starter #8
Hey Wolfe where can I buy a new one of these for less then $395 Ive found used ones priced $100 and slightly less but not new ones. Also what couldve caused this to go bad like it did. I remember the day my bike started missing I road it to work after lunch and ran over a small stick that dropped out of the truck in front of me since I couldnt swerve in time and since then its misfired. I also noticed that 1 of the yellow stator wires was smoking just before tgis stick thing and I fixed it cheaply but going to cut and splice a new wire in soon I dont know if that couldve caused it or not but I did buy this used as well.
 

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check your stator output, if it is doing what it should, then the CDI is likely bad. The last ATV I worked on had a primary part of the stator (which went through the CDI for coil excite / spark) then it had a secondary wire from stator to tell the cdi WHEN to connect the primary to the coil.

I used a scope to check all this stuff, but proved it was the CDI.

I do not know if the stators on these bikes are different that that chinese atv i was working on....

If one plug gets spark and the other dont, I would think it is not the CDI unless it has two drivers one for each plug.

Good luck

kenny
 

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I am curious....is the CDI open so you can actually get to the internal components?
I assumed it was a sealed unit, but never tried to open one.

There are plenty of bikes being parted out, I would assume you can get a used one cheaper...it either works or it don't.

If you decide to trash it or if you did open it up....PM me....I love to tinker with stuff like this!
 

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Discussion Starter #11
Well I bought a Kawasaki Multimeter at a big discount and tested the CDI and it doesnt even show any resistance at all except when red lead is on pin 1 and black lead is on pin 6 I get a 4.6ohm reading otherwise I get no readings at all. I then bought another cheap walmart analog multimeter just to verify that my older Kawasaki analog multimetr is acurate and it reads the same so I know my CDI is no good its failed the test badly.
Hey Mercury Im going to go work on my bike after all these rain days and Im going to test everything on it stator, retifier, alternator, junction box, checking all wires and such as well once the rain lifts. The CDI was sealed but I did open it and im going to check all the transitors in there as well just to see what exactly went wring with it. I have a big list of stuff to do to my bike its gonna get a good run through once I get a few more parts in for it all fluids will be changed a ear shave is in order as well Im currently have it stripped down right now for the ear shave and figured Id just check everything else on it. Thanks for the advice Ill definitely check it all out it sucks my bike is 45 minutes away so in a few more days im going to go work on it again and will keep you sll posted, but I will be buying a CDI for it here soon. Thanks all.
 

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I also noticed that 1 of the yellow stator wires was smoking just before tgis stick thing and I fixed it cheaply but going to cut and splice a new wire in soon I dont know if that couldve caused it or not but I did buy this used as well
I bet thats the main issue...its rare that these units go, especially on one that new...and like Merc stated, if there is any spark at all, then its not the CDI...they either work or they dont...no intermittancy...

There's an older VN in a scrapyard close to here thats pretty complete...even has an engine guard on it...I was gonna get it and maybe part it out, but Im trying to get rid of stuff, lol....30 yrs accumulation. I can mebbe try to just get a buncha parts off of it, but if I get it whole, I can mebbe get it for scrap weight...will know in a few days....I really dont need another bike here though, lol...
 

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Discussion Starter #13 (Edited)
Wolfie but why would my CDI not pass the resistance test. Could the stator cause my CDI to go out? That yellow wire could that have caused the CDI issue? Im going out to my storage building hopefully tomorrow if the rain doesnt start and im goibg to test it so hopefully everything else is good. I know I did change my coils, spark plug wires, spark plugs and battery out 4 years ago and I still had the misfire issue on that rear right spark plug. Im also going to check all the wires tomorrow as well.
Also if I have to replace the Stator whats a good one to buy OEM, Ricks or Electrasport. Ill be leaning towards OEM but heard of the other 2.
 

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Are you testing it right at the unit ?...if youre testing it at a connection away from the unit, then its probably just the wire....
Im FAR from an electrical expert...Merc is much better versed in these things...but if youre getting any spark at all...cant be the CDI.
 

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Discussion Starter #15
I pulled the CDI off of the bike and testing it right at the CDI itself. My thing is when I look at the wiring diagram the CDI wire goes to the coil through the spark plug wire to the spark plug so I wonder if it is possible that the CDI wasn't working properly on that one wire Im sure thats not possible but Im not sure since Im new to working on motorcycles. Im gonna have to look at the wiring hard which I will probably Saturday as its calling for rain for the next 2 days.
 

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Do you have a really good wiring diagram ?...if not, PM me your email addy and I'll send you a hi-res version I scanned myself...mebbe that'd help some...
Like i said, besides for basics, Im almost clueless as to electrics details...there's another active thread in here by "theone2043"....

http://www.vn750.com/forum/showthread.php?t=28913

That may just have a few of your answers. All kindsa resistance values and such....when I cant figure out mine, I get a buddy to help me and pay em off with beer/shine/burgers, lol....
 

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wiring diagram would help for sure.

Weak spark or ok spark until it warms up could be a coil, coils sometimes read resistance checks ok but as soon as the high voltage goes through the 2ndary side of the coil they 'break down' and 'short out' internally (sometimes)

Electronics is tough because there are many options all resulting in 'don't work'
 

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Discussion Starter #18 (Edited)
Yea I have a Clymer manual so I have all the diagrams but ty. I have 4 coils and swapped them out and its still the same spark plug not firing no matter which coil, spark plug wire or spark plug I put on the rear right side its the same no firing or weak firing. I am going to start the bike tomorrow to see if itll even start. I havent started it in 4 years and since this CDI has failed the resistence test I figured it probably wont start until I get another CDI. Im putting some money into this bike its a great bike and cant wait to get it running soon. It sucks that I bought this bike almost 5 years ago got 6-8 months worth of riding out of it and then it started misfiring or weak firing and thdn my back got worse and now Im just trying to get it back going again.
 

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Okay...your by Bowling Green, right ?...close ?...shipping would be about $7 and I bet I could get the scrapyard part for $25....so, $50 total for shipping, parts cost, and my gas (15 miles away), and wallowing in the mud removing....how's that ?
If ya want it, lemme know...I'll go over and remove it for ya....still not 100% sure on the price though....I wont rape ya...just my gas and the time it takes me to wash the mud off, lol....if they selll it to me for less, yer win...

Honestly, with all the parts I could get offa this VN, and all the guys lookin for parts, I should have all just send me 1/2 and I'll buy the whole damn thing and part it.....
 

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Screw it...Im buyin the bike, then sellin parts.....just need to get it to HERE, so I dont need to deal with mud....
 
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