Won't start, what have I done?

[Cammo]

+1 on flooded and dead plugs.

Sometimes they still spark well out of the bike but not strong enough to ignite the mixture.

They're pricey little buggers, it's a lesson you won't soon forget!

[BillyKnight]

Hi again,
well I tried another ignition CDI box but no change, the bike has always run the HRC hot up box as well but it makes no difference in or out.
I pulled the rear plugs out and they look fine, both spark ok. Still just the odd pop from the motor but just so dead, do you really think the plugs would just go off like that?
Could I have upset something else in the ignition? I see the power to the CDI box comes through the key unit and the run/off swith on the bars. I guess I will trace that circuit out next. Maybe get a new set of plugs too...
Thanks,
Billy.

[wullvfr]

so the bike does start?

does it start easily or does it take quite a few turns?

how does it rev(if starts)?

for the bike to start obviously it's getting fuel and a spark but if all of a sudden it dies then you have to determine whether it is fuel related or electrical.

if the plugs are in good condition,sparking and show no signs of a lean mixture or rich mixture then it sounds electrical.electrical problems are usually intermittent unless very bad which in may be the case here.

im not entirely sure if you have stated whetjer it starts or not!!!!!


william

[BillyKnight]

No it will not start, its just pops out of the pipe every ten seconds or so when the loaded up fuel ignites. It is almost unbelievably dead.
I think it is an elactrical fault, but there is some sort of igntion there. I will probably end up with new plugs but do not think they are the fault. Ultimately the power of the ignition is produced in the coil, that will be the next thing to swap over, the resistance tests come up OK but they do not show how the coil performs under load.
I will get there.

[wullvfr]

that is the downside to the coils,they can only be tested for resistance and it's really a stab in the dark when determining them faulty........but if you are getting a spark at all 4 plugs and healthy sparks at that,then the coils are more than likey working as they should.

is the engine definately turning over?sounds silly but just trying to think of possible causes!!!!

if the sparks are weak it could be one of a few causes,spark plugs themselves,ht caps/leads,coils,pulse generator coils!!!

try the ignition switch fuse!!!!!!!!!!!!

the ignition will still come on and engine will turn over but won't start....i think!!!!!!



william

[wullvfr]

if i remember correctly if the main ignition switch fuse was blown it wouldn't turn over at all,so on that note i don't think it's that


william

[BillyKnight]

Oh yes engine is spinning fine, I have even tried bumping it but no go. If the ignition fuse was gone there would be no spark I think, but already checked and OK.
I have not checked the spark on front coils yet as a bit tricky to get plugs etc out, but it's all hapening soon..
thanks for your thoughts,
Billy.

[wullvfr]

yeah there would be no spark,but it wouldn't turn at all....i couldn't remember as i had the fuse go but i remember it wouldn't turn at all

if the front was not getting a spark the bike would not start with choke but may start with some throttle,give that a little try before taking them out,also check the connections on the front coil just incase there is obvious signs of corrosion etc

i had a problem where the bike would not start even with choke except for when i gave it some throttle but as soon as i closed the throttle it just cut out,it would not idle at all.

it turned out to be running only on 2 cylinders and thankfully it was a easy problem solved.


william

[Cammo]

No it will not start, its just pops out of the pipe every ten seconds or so when the loaded up fuel ignites. It is almost unbelievably dead.

Plugs are flooded and busted....

[wullvfr]

Plugs are flooded and busted....

as stickshift say's,take the plugs out and give them a visual check.take them out more so after trying to start the bike and after the popping and backfiring......they should be soaked in fuel if the cylinders are getting flooded.

a good tip for starting the bike if it is flooded is holding the throttle fully open whilst trying to start(no choke)this draws in more air than fuel and hopefully clears the flooded cylinder.

if the engine is getting flooded,chances are the plugs are goosed and the spark is weak that it is not igniting the air/fuel mixture and the more you try,the more the cylinder becomes flooded
hence why after many try's you start to get the backfiring when there is so much unburnt fuel in the exhaust system



william