Voes switch is another sometime offender in the puzzle between fuel and ignition.

It's funny a lot of people rave about ngk but from my experience they fail when run rich and don't recover like I said put others in and no problems and once tuned no problems with ngk just seems odd that they fail under rich conditions and others don't.

ngk plugs do foul easy if the mixture is too fat , but a weak ign system will do that tooooo

Thanks for the input guys, and just to keep you up to date, since the plug thing was mentioned it made me start to wonder, so to satisfy myself I put a new set of plugs in that I had spare (I'm running NGK Iridium plugs they were fitted to the bike when I bought it and as I said it came with a spare set), and the problem persisted with the new set fitted, so I think I can rule out the plug idea, but thanks anyway for all the suggestions. Had a look online to get some info on plugs and this is a small extract from a site that I found: (this is the link to the site, it's interesting reading and debunks a lot of theories)

http://www.sciencedirect.com/science/article/pii/S2090447912000883

In spite of continued investigations to explore the impact of spark plug designs on combustion and engine performance, a complete clear picture is still far from our understanding. In the present study, the impact of spark plug design, represented by number of ground electrodes, on the engine stability was investigated using four commercially available spark plugs. The spark plugs were carefully chosen with the same point central electrode to eliminate any effect from the central electrode.

Cycle-by-cycle variations have been characterized by the coefficient of variation (COV) of cylinder pressure, indicated mean effective pressure (IMEP), engine speed and timing of 10% mass fraction burned.

Of the plugs in this study with a J shaped ground strap, several physical parameters appear to affect the kernel growth – the amount of crossover of the ground strap, the dimensions of the ground strap, and the gap width seem to be the primary factors in this consideration.

Multiple ground electrode designed spark plugs significantly slow down the early flame development, due to the increase in heat loses and the reduction in flame growth due the restricted flow directions.

The plug, type-D, that performed the best, was a plug with no ground electrode where the amount of heat loses was the lowest and there was no obstacles affecting the flame growth. A reduction of 7.3% in the time required to burn 10% mass of the mixture was recorded for this spark plug compared to SP type-A while an increase of 4.4% in IMEP was observed.

The COV of the type-D spark plug was the lowest of the four main test spark plugs where it showed a reduction of 23.8% and 17.1% in the COV of IMEP and engine speed respectively compared to the base spark plug, SP type-A.

The amount of heat loss from a spark plug leads the plug behavior towards higher cyclic variations over the spark position.

Hear you Dave and that's what I'm doing, will call the guys at CNC and see if I can get the 5 breakers / relays off them sent to me, and will see how it runs after their all replaced, thanks again everyone for your input much appreciated.

One thing I usually do is fit a dedicated ignition relay to cars bikes etc .Takes the load off switches and connectors.

Well just wanted to update everyone who contributed to this discussion, I finally got down to see the RJ at CNC Cycle Works in Dandenong, and after telling him about my problem he asked me a few questions, like do I use the choke/enrichment valve to start my bike, I said I do and told me to stop doing it and to just give the throttle a couple of twists and crack the throttle about 25% and start it that way, then he asked what Plugs I was running, I told him that I had NGK Iridium Plugs fitted and he immediately suggested changing them out for a set of HD Plugs which I did.

So to those who suggested this action it turns out that you were right, and for those who ragged on NGK Plugs it seems that you were right too!

I got home changed the plugs out and started the bike without using the choke and you guessed it, it started perfectly and ran without backfiring, took it for a long run and no issues with backfiring or cutting out (I reckon the cutting out was the faulty ignition that I changed).

So thanks to everyone for their contributions and Kiwi Dave the CNC guys were great thanks for putting me onto them, have ordered a new set of plug leads as I found a few hairline cracks in the insulation, RJ at CNC said that they could cause a problem now that the plug issue is fixed, thanks again guys all very helpful.

Yeah... The world of spark plugs is full of snake oil. Im like you and just run the HD ones for simplicity sake. I think the main settings of concern for them are plug gap (obviously) and heat range (to prevent fouling as well as remove heat)

Not very funny though all that trouble over ngk's .Like i said seen it so many times before that's what led me to believe it was your problem.

 

lol but perth hog it's been proven time and time again you will never convince me or any others that have had the same experience with ngk otherwise.I have had plenty of champion bosch plugs run rich and foul and then come good again .Wich does not happen with ngk .Why are you defending ngk do you sell them or something.It's also quite funny how cnc cycleworks knew to piss of the ngk crap straight away as well.

 

And your not going to convince me either independent,and no I don't sell them or get any kick back but my experience in
20 plus years in the trade working on from your mums car to crewing on 2000hp blowen race cars and working with
Some of the best dyno tuners in the country on a lot hi performance cars from blowen,turbo ,nitrous I have seen a few things and ngk seem to Handle the best in what I have seen and a Harley is not any special creature just a v2 air pump
And as cnc cycles said to replace the plugs that was due to the fact he would have known once fouled thay don't unfoul
My 2c

One of my first jobs at the age of fifteen was as a 'Lube Operator' anyone remember that term? Really I was just a glorified driveway attendant in a Servo, and I happened to do basic servicing on vehicles, you know the old grease and oil change etc. I also use to help with other major servicing, and one of the things that was always done when a vehicle came in for a 'Tune Up' was that the Spark Plugs were checked (checked not replaced), and if they weren't too worn they'd be cleaned in the old Spark Plug Cleaner and Tester, the plug would be sandblasted to clean all the old built up carbon etc on them, then they'd be re-gaped and then checked to see if they were breaking down under compression using the Plug Tester in the machine, if they passed they were then reinstalled, and this was back when plugs were really cheap so they weren't expensive to replace.

But nowadays they don't even attempt to check the plugs if they're servicing a vehicle, they just pull em out and throw em in the bin, I know that this is probably the best thing to do but if like in the 'Old Day's' the plug was cleaned and tested out ok, why throw it away? I'd understand this if the plugs were like a buck a piece, but with some plugs costing $20+ why aren't they cleaned and re-used. Is as was said earlier that nowadays once a plug is fouled its ratshit and can't be cleaned?????????????

I've got an 84 EVO and never use the Enrichner.
It fouls the plugs and cause all sorts of problems.
I just give it four Squirts and away I go.
I use NGK's too and have cleaned them if they arn't old and they work fine.

What I mean by fouling is over fueling the plug. If you say leave the choke on there is a much higher chance the ngk will shit itself and never come good. Others will come good when left to dry out or on trail bikes you pull in the hot start lever. It's not a coincidence Or a mystery It's a fact.

I use the enricher and NGK plugs but use it for no longer than about 10 seconds. Never fouled a plug.

Yeah its kinda strange isn't it that NGK plugs do that, and I wonder if you cleaned them in an old spark plug cleaner whether they'd come good or not, I tried cleaning mine with thinners and a wire brush but it didn't really do anything, just wondering if they were cleaned properly if they'd come good again?

The key DISADVANTAGE with those Spark Plug cleaner units is that they use an abrasive like carbide or the like; so if you do not get absolutely 100% of it out of the plug then you are going to be running some through your engine. I cringe to thing of the damage a piece could do to the cylinder walls etc.

New plugs would be the safest option.

I looked into it a little apparently you can burn off the carbon with a fair bit of heat from gas torch Anyone willing to try it .And from all of the dribble I read through the only reasoning I could find that made any sense was someone saying that the insulators glazing was not of the same standard it used to be because of the introduction of efi. Mixtures are more accurate and it isn't needed.
I must say that some of the higher grade ngk plugs with the v groove tips that I had come across surprised me as they didn't fail like the standard ones.
And ngk have never been an issue for me in cars bikes etc that are'nt running rich due to cam changes problems or leaving the choke on rich jetting etc.

Yeah I guess everyone has their opinion on which plugs are good and which are bad, thing is it's a bit like the old saying when comes right down to it "If it ain't broke don't fix it"!

In other words, if it's working for you then don't mess with it.