2002 R6 Misfire

[lihp]

Ok guys, my R6 developed a misfire at idle, and it has gradually got worse to where it's a very rough ride.

I'm part way through stripping the bike to get the carbs off, however, while there I am checking for a spark, coils resistance is ok, but when checking for spark by holding plug against an earth, I had a spark on 1 and 2, then #3 coil on #3wire wouldn't fire, moved #3 coil to #2 wire and still no spark, now there's no spark on anything.

After a short while I did #1 coil back on #1 wire, and spark came back, but then has now gone again.

Any ideas??

[0l0dom0l0]

Sounds like you have a naff coil. I think there are 2 coil packs right?

It might be the HT lead is dodgy. Are you testing it directly from the output of the coil or through the HT lead?

It wont start at all I assume?

I would test you have voltage going to the coil pack from the generator or whatever, then I would check the output of each coil. If that's all okay then check the resistance of each HT lead, iirc they should be round 7kohms? I think! Then if that's okay check the voltage at the spark plug end of the HT lead. If that's okay its either a loose connection or a nackered plug.

I hope that helps. People please correct me if I am wrong anywhere!

[lihp]

The R6 has 4 coilpacks which are integrated into the HT lead, so no seperate leads either.

The spark goes and comes back quite intermittently, The bike does start, but has a rough idle and very poor performance till about 6k, and hesitates at quick throttle changes.

As the bike has a datatool alarm/immobiliser, I decided to check the wiring, and noticed that while it was plugged into my battery charger (oxford optimate) that when I moved a connector the top green battery condition light flickered on and off.

This connector, is triangular in shape and has 3 wires, white blue and something else, but may be different it was a few hours ago since I checked before work lol.

I am going to check this further, and test for spark again while wiggling this connector to see if it has any affect on it.

Finally, Is it ok to keep letting fuel pump prime and run with no fuel in (tank is off), or am I better pulling the fuse for it, so I don't dry run it all the time?

Also while taking airbox off, I noticed the inside of the airbox near cylinder 1 (left hand side) that it was quite damp with fuel. The carbs do need cleaning and balancing, however I need to discover what this loose wire affects and the issue with the spark.

[0l0dom0l0]

Okay I didn't realize the R6 had the coils in the HT leads!

If it does start, spray WD40 on each header pipe. It will hiss at you. You can identify which cylinder isn't firing by the fact it wont sizzle. I hope that makes sense lol.

You can then work as a process of elimination from then when you have identified which cylinder it is.

Have a good look over the alarm side of things but I highly doubt the bike would start at all if the alarm was causing problems. Often they just cut off everything.

I can't understand why it was damp with fuel though. Are you sure it wasn't moisture? It will be gathered by cylinder 1 because that's the side of the stand, and the bike leans that way when parked.

With regards to fuel pump pulling the fuse might not be a bad idea, just remember to put it back lol.

It could still be a faulty HT lead/plug though.

[lihp]

Looked at the wiring diagram I have in work for my bike, and the connector in question appears to be for the Throttle position sensor or the Speed Sensor, so I am unsure why wiggling this connector affects the battery condition lights on my charger.

The bike was also stood for quite a while when I bought it, long enough for there to be marks on the discs from the pads. I'm still going to carry on for the moment and get the carbs cleaned and balanced.

Plug colours are all ok.

[0l0dom0l0]

if its for the TPS then that would explain a lot. I would look at that very closely in that case. It might be running very rich/lean if it isn't receiving info from the TPS

Possible its crap in the carbs then. Get them cleaned and balanced and I hope it sorts things!

[craigT19]

Its farely unlikely to be a tps problem, on the old carb models the tps isnt particularly complicated and doesnt have anything to do with fuel metering, the basically a control unit for the electronic ignition providing the ecu with info on throttle movement to optimise the ignition timing, at idle the tps isnt active

Sounds like you may have some shit in one of your carbs, a blocked jet a needle jet from what you have said.
____________________
Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
BCF member pops. sadly missed 1945-2003

[craigT19]

Oh and the petrol in the air box has probably come from the crank cases, of the bikes been stop for a while chances are some petrol has drained past the piston rings into the crankcases, its fairly comon and the petrol evaporates comes out the crank case breaver into the back of the air box where it condensates and leaves a petrol resedue
____________________
Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
BCF member pops. sadly missed 1945-2003

[lihp]

You have confirmed my thoughts regards to the TPS at idle, what puzzles me is why wiggling this connector causes battery status lights to change on the charger.

With regards to the fuel possibly past the seals, is it worth dropping the oil and replacing? I have used this bike for about 2 months now, or will it just burn off eventually.

I'm going to hopefully get the carbs off tomorrow morning and have a look over them, but this spark issue is interesting, though the battery may be weak if I've cranked it quite a bit, and is just coincidence?

[craigT19]

I wouldnt worry if the fuel did get past the rings it will only be a very small amount as it was what was in the barrel.

For the charger....who knows there somewhat of a mystery to me, ive found my optimate will ofter say full charge... yet if i wiggle the connector that attaches it to my battery it will swicth back to charging again.
____________________
Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
BCF member pops. sadly missed 1945-2003

[0l0dom0l0]

Its possible if the alarm was fitted after the bike was made that it was fitted incorrectly/differently.

Its possible that when you are charing the battery the current is taking the way with the least resistance and trying to charge something else, and when you disconnect that wire it then charges the battery. long shot though.

[lihp]

[lihp]

Just to update, while following the Yamaha service manual trouble shooting, everything tested ok, until I got to the Starter Circuit Cut off relay tests.

The test has 2 parts, testing 2 pins should have continuity in one direction but not in the other.

The way for "No Continuity" is ok, and has no continuity.
The way that should have "Continuity" doesn't cause my meter to beep on a continuity test, but has a reading of 760ohms which seems a little high for something that says it should have continuity.

Does anybody have a 99-02 R6 they can test there cut off relay on, or know if this is correct.

[lihp]

The part number is

5EB-81950-20

Starter circuit cut off relay

[gray84]

not on my bike but i have a spair one sitting in my garage.. where are you?
____________________
Road bike - 2002 YAMAHA R6(SOLD) 2008 YAMAHA R1(SOLD) 2007 APRILIA SXV 550(SOLD) 2007 SUZUKI GSXR 600
Dirt bike - 1989 HONDA CR80sw(SOLD) 1996 YAMAHA YZ125(SOLD) 2006 yamaha yz250(SOLD)

[lihp]

I'm in Warrington, Cheshire, what about you?

In this PDF
https://www.yzfr6.net/manual/r6_manual_electric.pdf

page 8-15

It's test 12 that I found it on.

The test for "continuity" actually reads around 760ohms, but to me continuity should be nearly zero.

I assume this can stop a spark, as that's the troubleshooting procedure for no spark, or intermittent spark.

[gray84]

https://inlinethumb28.webshots.com/25755/2259652350057585097S425x425Q85.jpg

is this it?

im in lichfield west midlands
____________________
Road bike - 2002 YAMAHA R6(SOLD) 2008 YAMAHA R1(SOLD) 2007 APRILIA SXV 550(SOLD) 2007 SUZUKI GSXR 600
Dirt bike - 1989 HONDA CR80sw(SOLD) 1996 YAMAHA YZ125(SOLD) 2006 yamaha yz250(SOLD)

[lihp]

Looks like this

https://www.2roo.com/upload/vignettes/s_430/2010/10_11/738714_fc77a390ae.JPG

It's mounted right near the battery terminals on it's side.

[gray84]

oh its not what i thought then sorry...
____________________
Road bike - 2002 YAMAHA R6(SOLD) 2008 YAMAHA R1(SOLD) 2007 APRILIA SXV 550(SOLD) 2007 SUZUKI GSXR 600
Dirt bike - 1989 HONDA CR80sw(SOLD) 1996 YAMAHA YZ125(SOLD) 2006 yamaha yz250(SOLD)

[0l0dom0l0]

its a long shot but it might be similar to the one on my fazer that I am breaking. I will go and check the part numbers when I get a chance.

[craigT19]

continuity wouldnt read 0, continuity simply means there is a complete curcuit, and if there is a curcuit there will be some resistance.

Your getting lost in the workshop manuals troubleshooting.
Your looking at your starter relay when your problem isnt starting the bike...its the way it runs.

The starter relay simply bridges your battery directly to your starter motor to give it mazimum amps for the starting cycle, once the start button is released the relay becomes a bridge for the battery to the rest of the electrics.

As said above from what you have said with your bike running poorly at idle but ok when the revs pick up points to a few things.

If i was working on your bike this is probably what i would look at.

1. Shit in one of the carbs would be my first stop probbably a blocked needle valve.

2. More serious is the possibility of a cracked valve head, poor valve seat. This could cause the problems your getting because at low rpm your loosing compression from one cylinder before it ignites properly but this becomes less obvious at higher rpm as the compressed fuel air mix has less time to seep out.

The second is extreme but is possible i had it happen on my zx6r

Start simple.. you know the bike runs.. you know the carbs are getting fuel, run the bike at idle and quickly touch each of the header pipes (or spray summin on them) if one of the 4 is running poorly it will be noticably coolder than the others.
Once u got your cylinder you know that theres a problem between the fuel going into the carb...and getting burnt in the engine.

So remove the carbs and check there clean and in good order. If thats all good get a compression check done.... poor compression? bad ring or valve XD
____________________
Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
BCF member pops. sadly missed 1945-2003

[craigT19]

[lihp]

Apologies if my initial post was difficult to follow, it was posted in a rush.

There are actually 2 seperate issues, that I don't think are related.

1. Poor idle, sounds like misfire, this I believe is dirty carbs due to being stood.

2. No spark on any cylinder, but had one a few days ago.

While following the Yamaha tests, everything tests fine, until that relay, Which although I am not entirely sure of it's purpose, it must have control of the spark for Yamaha to include it in their test procedures?

I am an Electrician so understand that 760ohms is still a circuit, but for something that states should have continuity I believe should be a lot lower than that, for a specification where 760ohms was correct I'd expect to see a range of resistance, such as when doing tests on coils etc.

This is why I am looking for somebody with another one, to do the same test as what's on the PDF, if it's the same or very similar it's not the issue, but if it reads a very low resistance, then this I believe is a likely cause.l

[craigT19]

oh right i see, if if was a never bike i would say you have an imobiliser issue, do u have an alarm and if so what one? if i can remember ill send you a private message on how to temporaraly bypass your alarm without actually removing it.
____________________
Bikes owned :- 2001 nsr125, 1999 zx6r, 2006 yzf-r1, 2009 xmax 250, 2012 yzf-r1, 2015 MT-07
Current bike : - 2016 MT-10
BCF member pops. sadly missed 1945-2003

[lihp]

It is a Datatool System 4 that I have installed on it.