Sv 650 coil wire
 

Hi anyone know where the white wire on the rear coil ends up i know it goes to icu but where to from there i have no power on rear coil wires when i put a multimeter on them, i have a live on the orange rear coil wire when i use a frame earth but no earth on white wire got a missfire changed icu, coils, plugs checked loom at a loss now what about coil generator please help

Re: Sv 650 coil wire
 

You didn't say whether it's a curvy or a pointy. On a curvy the white wire comes from the igniter, on a pointy from the ECU - it fires the coil but it isn't a straight path through either unit - it will be a semiconductor device that does the triggering based on the signal from the pick up coil. There's little you can check on the coil other than it's impedance (140-230 ohms) unless you have access to an oscilloscope or Suzuki's peak hold thingy.

Have you changed plug caps and HT leads? I'm sure R1ffR4ff will chime in with the spec and/or part number, he remembers that stuff. If it's a curvy there are a few carb issues that can cause a misfire, if it's a pointy a dirty fuel injector could could cause a problem.

Re: Sv 650 coil wire
 

This post covers the Plug caps both in the UK and the USA,

https://www.svrider.com/forum/showth...hlight=SD05FMR


Depending on the SV version there's a few wiring diagrams around,

https://www.google.co.uk/search?q=sv...w=1326&bih=627

Re: Sv 650 coil wire
 

This may be useful - posted recently:

A present for all Gen 1 Owners
https://r.tapatalk.com/shareLink?sha...0&share_type=t


Sent from my iPad using Tapatalk

Re: Sv 650 coil wire
 

Sorry its 2001 year yea ive changed coils twice its the rear coil defo there's no negative feed from white wire if i test power supply on rear coil there is none unless i use the frame for a earth was wondering where the white wire goes from icu not towards coil but the other way to where it joins to think must be a problem there was wondering does it go to coil generator basically tried so much and not getting anywhere with it even on idle ut sounds a little spluttery so to say not smooth, other day i took it out on motorway opened it up got up to 80 mph and started missing firing on one cylinder slowed down and it came back in

Re: Sv 650 coil wire
 

Imagine the pulse coil is a switch - when the crankshaft reaches the correct position the switch closes and sends a signal to the igniter and, depending on a number of variables, the igniter will, at the right time, then supply a momentary return path for one of the coils which will cause a spark.

You said you changed the coils - did they come with new leads and caps? Have you cleaned the carbs - the choke plungers on the carbs can stick and cause rough running.

There was a case when the pick up coil affected 1 cylinder:
http://forums.sv650.org/showthread.php?t=133901

but it's unusual.

If you use google to search this site it works better than the site's own search function. As an example, type everything between the quotation marks into the address bar on your browser.

"site: sv650.org pick up coil"

Sv 650 coil wire
 

Good morn,
I've just had a look at the wiring diagram for a curvy (see the link above). Seeker is absolutely right: the orange wire will be a permanent +ve feed (probably at 12v), the white wire will only have continuity (to the negative return cct) when the ignition sensor tells the ignitor to do so (so it is sort of replicating how contact breaker points work). In that case one would not expect to measure any potential difference there. I'm guessing that by negative feed you mean a potential between the orange and white wires - but one would not expect to see anything there (except at the instant the ignitor creates continuity). A potential between the orange wire and the earth return path via the frame is entirely consistent though - so it would seem that part of your system is working as it should.
I'd start looking at the other items that Seeker mentions, or the carburettor issues listed above.
Good fortune,
Alan

Re: Sv 650 coil wire
 

Thanks guys i did have caps and leads with new coils yes, i can have a look at carbs too worth a look just seems electrical fault the way it missfires in and out so fast as if the same as damp leads on a car
Appreciate all your help ill try test the rr, pulse coil ohms, stator output today see if that throws anything up,

Re: Sv 650 coil wire
 

Check for air leaks @ the Air filter and even leaks in an exhaust can cause backfires that can sound like misfires.

Re: Sv 650 coil wire
 

you might want to do a compression test too. On some older bikes there was an issue with foam from the airbox partially blocking the air intake.