Yamaha R6 Forum: YZF-R6 Forums banner
1 - 6 of 6 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter · #1 ·
Hi all!
My 00 R6 has decided to develop a bit of a problem, bit of backstory required:

initially when trying to start the bike the dash would immediately cut out and nothing would happen, letting go of the ignition would not bring the dash back on. I discovered if I manoeuvred the handle bars backand forth with some force and tried starting it would come back to life - this was a bit of a process and wasn’t super reliable but got me out of a few sticky situations!

I repinned the main white plug between the dash and main loom on both ends, (the one by the steering column) during this process I found many corroded wires with only a few strands left. Yippee this is the problem I thought, nope! Problem changed now!

I’ve attached videos for those that have already read all this and are getting sad lol! Now when the ignition is pressed you’re greeted by a very unhealthy buzzing which I can only assume is the starter relay furiously clicking back and forth? Can’t say I’ve head the noise before but comes from the battery area. Among the other issues like the dash not lighting up and changing sidelights to dips to main beam etc makes the dash completely cut in and out!

so it seems I have a wiring problem somewhere but was hoping one of you might point me in the right direction😀

the only obvious thing I’ve been able to find is what I believe to be the starter relay: the M negative terminal has begun to get some surface corrosion? (Pic attached). Really not sure where to start, I don’t want to pull the loom and start checking wires!

anyone had this before? Also thought it might be the killswitch unit, it was replaced with a known good unit and wire, this fixed the problem for

a day, now it’s back lol. So whatever I did manoeuvred something in such a way to let it start once.

Sorry for the biography guys - the battery is also sitting comfy at 12.8v, was 13.05 before I started cranking this eve, fresh off the charger.
Material property Gas Tints and shades Cosmetics Automotive lighting

Motor vehicle Electrical wiring Auto part Wire Cable
 

·
Registered
Joined
·
3,544 Posts
Haven't reviewed all the data, but one valuable tool for your "virtual" toolbox is "voltage drop testing". This allows you to literally pin-down bad connections in a circuit. By that I mean, you can insert a straight-pin through any wire at any point to get a voltage reading at that point.

Example:
To find a bad connection between the battery positive and starter positive, first measure battery voltage with the ignition activated. Let's just say that's 12.6v. Put one test lead at the battery positive post, and the other at the starter POSITIVE post. Yes that is correct, both test leads are on the same side of the circuit. Next, fully load the circuit by... you guessed it, trying to crank the engine. As you crank, look at that volt meter. Let's say you get a reading of -7.2v. (or 7.2v depending on how your test leads are arranged) This means that between that battery positive post, and that starter positive post, 7.2 volts is being lost... or "dropped". So how to narrow it down? Look at your circuit diagram and move one of the test leads further upstream.... or downstream. Repeatedly measuring at each point lets you pin down bad a connection(s).

It's also important to test your grounds using the same method. It's possible that the positive side of the circuit feeding the starter is actually fine, and it's the ground between engine, rectifier/regulator and battery that's the issue. A loss of 6% or greater, is considered excessive. In the example above, the starter would only be getting 5.4 volts. (12.6v - 7.2v)
 

·
Registered
Joined
·
3,544 Posts
Looked at the videos... electronics can do some weird things when low on power but I'm not sure that's the cause here. You may have electrical short(s). Focus on things around the steering head.
Look for rubbed through wire harnesses. Wire harnesses that aren't properly secured are subject to abrasion damage. The manual has diagrams that depict how and were to route wires, cables, lines, as well as how and where to secure them.
 

·
Registered
Joined
·
39 Posts
Discussion Starter · #5 ·
Looked at the videos... electronics can do some weird things when low on power but I'm not sure that's the cause here. You may have electrical short(s). Focus on things around the steering head.
Look for rubbed through wire harnesses. Wire harnesses that aren't properly secured are subject to abrasion damage. The manual has diagrams that depict how and were to route wires, cables, lines, as well as how and where to secure them.
hey man thanks for the thorough replies!
I have a dummy main loom I’ve been using to familiarise myself, I’ve been using ohms to test the resistance in all of the wires in the bike loom I could get to. Identified one with infinite resistance that seems to be my tach light based on my wiring diagram! Not the issue at hand but will still aim to fix.

I actually built this bike from the frame up so it’s entirely possible I have routed a wire incorrectly - I did notice at the start of the build that my two headlight relays were misbehaving - odds on a bad relay causing all this mischief?

for some reason I never thought I could put my volt meter onthe same side of the circuit, don’t know why I didn’t think that would work lol. One thing I noticed was that the neg on the battery and the bolt going to M on starter relay had good resistance, but when I measured the M post on the relay to the neg it was infinite resistance - not sure if this is a red herring though as the post seems to be made of brass so not necessarily conductive? Just a thought.

not sure if this helps either but when I thought I had it fixed (after replacing the killswitch module) I was cranking the bike for about 20 mins that morning not realising I had the fuel petcock turned off. Once that was turned on the lines primed up properly, turned it over and it nearly fired, readjusted the choke to try again and the buzzing symptom returned! (Does this seem like a loading up issue maybe?)

after replacing the kill switch I had the bike running for 20 mins that night, turned off the petcock and drained the carbs just to get rid of the old petrol and it hasn’t run since, so semi intermittent I guess?

so what I mean is it cranked over and over with no issues until it actually had fuel and had to run properly? Is the best way I can describe lol - might be coincidence, hope that makes sense!

Will try your suggestions this afternoon and see what I can find! Although I think that M post on the relay is very suspicious
 

·
Registered
Joined
·
3,544 Posts
Voltage drop testing works for finding bad switches... and relays contain a switch. Just test the wires entering and exiting it. Remember that the wire has to be loaded to its potential by the circuit or the test will not be representative. Starter motors in general in rare instances have been intermittent but are easily eliminated by jumping a wire directly from the battery. The weird stuff with the turn sig and lights could be miswiring and/or insufficient grounding. Resistance testing is often inconclusive but for extreme issues with connection because the volt-meters output very little power.
 
1 - 6 of 6 Posts
Top