Republished: An Update on the SV650-S Charging/Ignition Problem
This was originally published on benscomputer.no-ip.org in 2009
As I
mentioned previously, the bike was due into the Garage on Friday
to sort out the charging problems that it seems to have developed. The
symptoms also included a misfire at low revs (anything below about 2500
RPM).
Unfortunately, the Garage found some more urgent repairs that needed
doing (Brakes had seized again, amongst other things) so I hit my
budget ceiling before they could really take a look at the original
problem.
So on Saturday, I got out the toolkit again and had a look.
There was still a misfire at lower revs, and keeping the revs up whilst
braking puts one hell of a strain on your right wrist. This is an issue
that needed sorting, so whilst I thought about what the next step might
be, I pulled the plugs. The Plug from the rear cylinder looked pretty
much like they do when they have been used, albeit a little black. This
is normally a sign that the engine is running rich, but as I wasn't
entirely sure that the cylinder was firing every time, I kinda figured
this was par for the course.
But when I pulled the front plug, I couldn't believe the state of it.
The thing about spark plugs is that no matter how long they have been
in an engine, the external section always look pretty clean, yet this
one was crusted with rust, dirt and all manner of other krud.
In fact it was so bad, that the sealing ring wouldn't sit flush with
the rest of the plug (you can just about see it in the picture).
Obviously I swapped both plugs for new ones. Once I had re-connected
everything, using lots of grease to help seal the front plug, I hit the
starter. She ran fine, so I went back to sorting out the charging
system. Except.... the battery was charging without my additional wire
connected.
My only guess is that between them, the plugs were demanding so much
from the Stator that there just wasn't enough trickling through the
Regulator/Rectifier, the resistance of the factory cabling between the
R/R and the battery is much higher than in my lead, so perhaps this is
why the additional lead made a difference.
The boot at the end of the spark plug cap was pretty knackered on the
front cyclinder, unfortunately I didn't have a spare,s o for now I've
had to put it back in. I'm guessing thats probably why the problem came
back this morning after I had washed the bike, but a quick dose of WD40
seems to have returned the bike to a running condition again. Once the
bike shop opens on Monday I'm going to grab a new rubber boot, and a
Fenda Extenda which should hopefully stop this problem from
re-appearing the next time it rains.
So if you are having problems with the SV, it appears Spark plug well
can affect much more than you would initially expect, so it's probably
worth grabbing a few CR8E's to keep as spares. Make sure Pipe Cleaners
are on your consumables list, that way you can keep that drain hole
clear, and a Fenda Extenda will do no harm!
There are probably a few who will read this and say, "Spark plugs
should be the first thing you check!" but I'd guess they have probably
never worked on an SV. Technically the statement is right, but the
front plug is an absolute nightmare to get to, especially on the faired
version. I've still got grooves in my hand from the radiator yesterday,
there just isn't room to get your hands in there, and once you do
everything is done by feel. It's actually easier to check the Carbs and
the R/R than it is to change one spark plug!
Still, despite that, it should be the first thing you check, as it
turns out the gaps would have needed adjusting on the old plugs had I
not replaced them.
On the plus side, I learnt a hell of a lot more about the SV's
electrical system than I would normally need!
