1st Gen front plug not firing fix (Hopefully)

Aaron Turner synfinatic at gmail.com
Tue Jun 28 17:17:55 PDT 2011

Yeah, many people have told me and I can confirm the stock suzuki SV
R/R's are pretty bad.  The 2nd gen's are better then the first, but
that's not saying much.

I recently swapped my R/R for an 07-08 CBR 600RR which is MOSFET
based.  Not only does it run cooler, but it's a much better design.
Since it's also a 5 wire deal, it's pretty straight forward to swap.
You can find them used on ebay for about the same price (maybe a
little more) then the Suzuki R/R's but totally worth it IMHO.

If you've got a lot of free time, this thread is pretty informative:

On Tue, Jun 28, 2011 at 3:07 PM, Steve Munyon <stevemunyon at comcast.net> wrote:
> Short story:
> The problem was a weak battery combined with stock Rectifier/Regulator
> wiring that needs to be a size or two larger.  Once I made the change, the
> weak battery voltage at idle went from 13.1v to 14.2v.
> Summary:  keep the #@% battery charged and don’t assume that revving the
> piss outta the engine while on the track will charge the battery.
> Long story:
> I’ve been jotting down the voltage levels as I’ve messing with it.  After
> seeing both plugs fire the next day, I made the mistake of charging the
> battery overnight.  I should have left it alone until I could duplicate the
> original problem.
> This forced me into looking for a weak link in the electrical system.  So I
> got out the voltage meter and recorded the initial states of battery
> condition.   I also checked primary and secondary resistance in the coils,
> etc., which were spec. I also put the street lights back on the bike, it
> wasn’t too hard, because I had made up some brackets to see what the SV was
> like on the street a few years ago.
> The battery with the ignition switched off was 12.47v.  Anyway with the
> headlight (low beam) as a load, the battery voltage dropped to 11.8v after
> 5-10 seconds.  So I think the battery is marginal.  I started the bike and
> the voltage went to 13.1v.
> I checked the primary side of both coils with my scope and I was seeing
> 400v.  The shop manuals states 150v & up, but a scope is a lot more
> responsive the just a peak and hold meter that the factory manual suggests.
> To me, that explains the higher peak voltage.
> I took the bike for a 20 minute ride and the idle voltage was still 13.1v,
> so I revved it to about 5K and the voltage was 13.3v, when I revved the
> engine higher the voltage dropped back to 13.1v.  I’ve been searching around
> the ‘net for similar problems.  One interesting find, was a bad solder joint
> on the signal generator pickup, but my solder joints looked good.  Another
> find, was that most Suzuki’s have weak regulator/rectifier based on ‘SCR’s”
> while other bikes have an R/R based on ‘MOSFET’s’.  Google them if you’re
> interested.  As a band-aid for the weaker R/R the author used 12 gauge wire
> with a 30 amp fuse to provide a more substantial current path then the
> standard Suzuki wiring which looks like a 14-16 gauge with lots of
> connectors.  Whenever I see an electrical connector I always figure on a .1
> v drop at each connector.  So I ran a 12 gauge wire from the R/R output
> connector directly to the positive battery terminal and took some
> measurements.  Key off battery voltage is 12.44;  key on and headlight on
> battery voltage is 11.9,  started bike and voltage jumped to 13.6v, after a
> minute the idle voltage was up to 14.2v and when rev’d the voltage was 13.8.
> Next I removed the jumper wire, went back and cleaned all the connections,
> checked the voltage and the voltages were back to where they were before,
> low.  At this point, I soldered in the additional 12 gauge wire and the 30
> amp fuse ending with a terminal lug so I can screw the lug to the positive
> battery terminal.  Checked the battery voltages again and they were back up
> to the jumper wire voltage levels and sometimes a little above.  I also
> clipped a ½ inch off the spark plug wire just to make sure the connection to
> the coil is good.
> So that wiring fix combined with a new Yuasa battery I just ordered and I’m
> about 95% sure I’ve got the problem fixed.  I thought about going to a
> lightweight battery, but after being stranded at the track without a bike I
> wanted some old age, proven technology.

Aaron Turner
http://synfin.net/         Twitter: @synfinatic
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Safety, deserve neither Liberty nor Safety.
    -- Benjamin Franklin
"carpe diem quam minimum credula postero"

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