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Discussion Starter #1 (Edited)
We bought a non running first gen over a month ago. The PO salvaged it ~14 years ago and due to that it has aftermarket guage, headlight, and the wiring harness is fairly hacked up. It has tabs from 2018.

So far we have acid cleaned the gas tank, rebuilt the carbs and replaced a bad starter relay/main fuse. Prior to disassembly we did hear it ignite once or twice on starting fluid.

Currently it has no spark on both cylinders but everything else is working. We went through most of the ignition system last night and it gave us little direction.

Ignition- tests fine, we see continuity across two circuits and 100 ohm resistance across the third when in the on position.

Pulse generator coil - 188.7 ohm
TPS - 5.06 K ohm

Front coil - 11.7v
Primary winding - 4.5 ohm
2nd winding - 25.3 k ohm and 30.03k ohm with plug

Rear coil - 11.82v
Primary winding - 4.6 ohm
2nd winding - this tested in range the first time very similar to the front coil. We tested it a second time a few hours later and could not see any continuity. We removed it from the bike and still can't see any continuity. So it may be faulty but this should only affect the rear cylinder.

We don't have a peak voltage tester. Both the neutral switch and side stand switch were bypassed by the PO. I have not seen any procedure for testing the ignition control module. We tried a spark plug from a running bike. We are currently using a car battery and jumper cables to test it. Any ideas or common faults? Trying to avoid throwing parts at it.
 

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The ignition system on the SV650 is simple. Here is a race harness showing the minimum necessary for the ignition to work. If the pulse generator resistance is good (also check to be sure it is not shorted to ground) and the coils are good, and power is good but still not spark, then likely the ignitor (CDI) is bad. Generally, the ignitor is very reliable but if the R/R has failed on this bike it is possible to be damaged from over voltage.

There is no good way to bench test the ignitor stand-alone. If you know someone with an SV, a good test is try your unit in the other bike, see if it sparks.

54678


Welcome to SVRider!
 

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Discussion Starter #3
Thanks for the help! I'm curious what in the stock wiring harness is the diode suppose to be? I checked continuity from plug to plug of all the comparable wires in the stock wiring harness in the picture you posted. Excluding the yellow/black and fused red wire off the kill/start switch as the stock wiring diagram is pretty different there. The rest of the diagram is basically the same. I'm trying to rule out the main harness before I try to find a new CDI... A replacement CDI appears to run close to what we paid for the bike :(. We did buy this bike for hopefully being a track bike if we can get it running good, but I still want it to be street legal.

The rear Coil again showed no continuity on the 2nd windings today after a good amount of fiddling so I'm going to assume its bad. Just a bit perplexed because it did test good the very first time. Regardless I should still have spark on the front cylinder... The PO cut into the main harness for a aftermarket speedo/headlight, neutral and sideswitch bypass. Most of it makes sense... I just feel I am missing something minor that is disabling spark.

I understand the R/R is a known issue but without the bike running I don't think I can trouble shoot it at all?
 

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Thanks for the help! I'm curious what in the stock wiring harness is the diode suppose to be?
The diode is wired across the starter relay coil. The purpose is to suppress the large inductive voltage spike (> 100v!) when the starter relay coil is released. Google "Flyback Diode" for a detailed description.


... Regardless I should still have spark on the front cylinder...
Agreed.


... I understand the R/R is a known issue but without the bike running, I don't think I can trouble-shoot it at all?
If the R/R is stock, do not even try to trouble-shoot it, it is a disaster waiting to happen. Chances are it has already failed and is the reason why the bike has no spark. Replace it ASAP(!) with a cool running MOSFET type R/R. The FH008 from a used bike is a good choice.
 

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Discussion Starter #5
Okay I'll look at the diode but I'm sure it's fine since it would be pretty obvious if it failed.

The R/R is the factory unit. Pretty much ruled everything out other than the R/R and CDI. We will try to check the CDI in another bike otherwise we may just have buy a used one. Then replace the R/R before we try starting it again.

This bike isn't a priority project currently so it might be a awhile before we get a replacement CDI.
 

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The diode will not cause no-spark, it is only there to snub the starter relay voltage spike. The bike will start and run even if disconnected but it is good to have as it protects the other electronics on the bike.

Definitely replace the stock factory R/R ASAP!

Good luck with your project.
 

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Discussion Starter #7 (Edited)
Just adding a follow up here. We tested the CDI in a different working SV today and it confirmed no spark with our CDI. So replacement CDI and coils ordered along with a Honda R/R.
Hopefully after that she will finally run.
 

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Glad you found the problem!

And thanks for the feedback, Kat, it is great when folks post a follow-up. (y)
 

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Discussion Starter #9
Well, parts arrived today! A used 06 CBR 1000 R/R wired up, used CDI and used rear coil all arrived today. Verified spark then reassembled and the she fired right up! Her name is now Sparky!

Figured I'd mention it but this bike did end up having a <$20 eBay R/R installed that looked pretty new with no markings and practically new spark plugs. So I'm sure the PO was struggling or having spark issues before parking this bike. We bought it for $500 including front and rear stands.

I do have some questions on the R/R mod and the best wiring options. We noticed the yellow wires from the stator and the stator extension harness both get pretty hot. We have it temporarily wired in to test functionality. I went through quite a few of the R/R threads but the best wiring I'm still not sure on as a lot of them are missing pictures.

Overall she runs pretty well. Still very much a project bike and has yet to leave her stands. New battery and valve adjust are next.
 

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I'm curious, did you have constant 12v out of the coils when you had no spark? I replaced my R/R and havent used the bike in a while. I tested the replaced R/R, which had 30 min. idle time on it, max, and it is of course shot. I get no spark, just 12v when the ignition it on and when it is cranking as well. I'm also curious what could cause the R/R to fail so quickly and what else it may have damaged, like the CDI.
Any advice you have would be greatly appreciated.
 

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Discussion Starter #11
I'm curious, did you have constant 12v out of the coils when you had no spark? I replaced my R/R and havent used the bike in a while. I tested the replaced R/R, which had 30 min. idle time on it, max, and it is of course shot. I get no spark, just 12v when the ignition it on and when it is cranking as well. I'm also curious what could cause the R/R to fail so quickly and what else it may have damaged, like the CDI.
Any advice you have would be greatly appreciated.
IIRC We had 12v to the coils when ignition was on. The bad coil we replaced tested bad on the second windings. How did you test your R/R is bad and what R/R is it? It definitely should not fail after 30min.
 

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I removed the r/r and used the chart in the shop manual. The 3 legs were always open between one another in either direction. The red had was within tolerance for all measurements. The B/W only passed when tested R+ B/W-
I replaced it after it drained my battery then started smoking when i jumped it. After that, i didnt ride for a while. i put a cheap r/r i found on ebay, unaware of the horrible rep they have. I changed the oil, checked plugs etc. I started it, let it idle for 15-20 mins. Took some measurements on during that time, everything seemed ok. Then I touched the r/r and it was HOT. I shut it down.
One other odd thing about the R/R is the harness, as in single harness. Its a 6 plug harness, 5 wires. When I look, and even in the manual it shows two separate harnesses from the R/R??
Since that time, I havent done much. I do want to note that there was an attempted theft while being stored. The ignition switch cylinder was drilled out. The headlight housing had been removed, there was a battery (not mine) in the box.
I replaced the ignition switch, gas cap and seat lock with a set that claimed it was for an 02, however the bolt pattern of the gas cap cover is not correct.
The generator continuity test was good. Coils, too.


55019

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IIRC We had 12v to the coils when ignition was on. The bad coil we replaced tested bad on the second windings. How did you test your R/R is bad and what R/R is it? It definitely should not fail after 30min.
 
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