2 cynlinders not sparking.

[odachi]

Basically, my 4 has gone to a 2 and she's a heavy lump with half the bike.

Recent snow here in the UK and a bike that lives outdoors, the bike has spent little down time due to the weather on a daily commute apart from one day when the choke wouldn't budge - frozen I assumed. Squirted some oil and the choke the day later moved to on, but wouldn't come off. The weekend passed and it went back to normal.
The day later, when warming up the bike cut off. Turning back on, with the choke still on it would only rev to 2k instead of 4k, taking the choke off killed it unless I turned the idle up.

Checked the plugs, 2 and 3 were caked in soot - swapped them out to no avail. No misfires or other strange noises other than how quiet it is - and the smell of petrol it's wasting.

I'm thinking the moisture of snow under a warm bike has caused issues somewhere. Next weekend gonna check the HT leads, anything else to look for?
I'm sadly not riding it anymore as I'm sure it'l eventually blow up understrain - that and 10miles drinks a lot of fuel.

[Slofuze]

Sounds like you might have an issue with the right coil. I'd start with simple first. Swap the coils out and see if you can get 2&3 to fire up.

[TRPUT]

^ +1

If you're lucky, you might find it is just a corroded / loose connection to the coil rather than the coil itself.

[boomer_95]

i agree with slofuze. swap the coils and see if it is still running on the same cylinders. if it starts running on 2&3 but dies on 1&4 then the coil is most likely the issue (check to make sure the wires are properly installed before replacing coil). if 2&3 stay dead like before, then your trigger lead may be bad, somehow, for that coil. if everything works just dandy, then you probably just had a loose wire

[odachi]

Swapped out 2&3 for 1&4, and it didn't fire up.

Just for the sake of it, checked 2&3 and they did spark.
After some trial and error using a spare plug it turns out there is a dead coil - but its the wrong one we thought it was.
I'm guessing 2&3 were sooted purely because of the strain.

Local dealer wanted £80 + VAT for a new coil, however ebay only wanted £20 so it was a no-brainer. Should have her fixed up next weekend hopefully.

[DocCannabis]

having the same issues, except 1&2 are dead 3&4 fire... I shall try the swap tomorrow!

Thanks for the info fellas

[92xjunker]

having the same issues, except 1&2 are dead 3&4 fire... I shall try the swap tomorrow!

Thanks for the info fellas

Your problem is simular but not the same, If what you state is correct, because 1&4 are on the same coil and 2&3 are on the same coil. you may have bad plug wires or boots asuming that you changed the plugs

[DocCannabis]

Yea I was incorrect, amateur mistake (I forget they cross over)

Left coil had no fire... lol right one did.

Swapped the coils, they both arc decently on all wires...

Going to attempt another swap(back) and power test... if I do it correctly I'm hoping it was just dirty connectors, I did clean them up as I was swapping...

[Mojoe]

you know, one thing you should try is heating up your coil with a hair dryer before doing anything. sometimes they just get a wee bit of moisture in them. I have had it happen a few times on bikes cars and garden tractors. it's actually quite common, but 99.9 of people just assume the coil is shot and they toss it.

many times after you heat it up to dry it out, it is good for a very long time. other times it isn't. my dad's coil on his garden tractor does it. he has an old hair dryer hanging on the wall just for that purpose. takes about 5 minutes. I ask him why he doesn't just buy a new coil, but at something like $150 he just said fuck it and heats it up. says when it stops working completely he will get a new one.

[DocCannabis]

you know, one thing you should try is heating up your coil with a hair dryer before doing anything. sometimes they just get a wee bit of moisture in them. I have had it happen a few times on bikes cars and garden tractors. it's actually quite common, but 99.9 of people just assume the coil is shot and they toss it.

many times after you heat it up to dry it out, it is good for a very long time. other times it isn't. my dad's coil on his garden tractor does it. he has an old hair dryer hanging on the wall just for that purpose. takes about 5 minutes. I ask him why he doesn't just buy a new coil, but at something like $150 he just said fuck it and heats it up. says when it stops working completely he will get a new one.

Good point man, never thought of that... though I don't know where I'm gonna find a blow dryer at the moment

--------
Now both coils are firing on all 4 wires Seems weak, I didn't get to test them yet though. Good ole Father Person had to see why the lights were on in his shop at 9pm lol


Edit: Oh! Btw Odachi

[boomer_95]

either it was a loose wire or what mojoe said, coil/wire with moisture in it. switch back and see if the problem continues. if not, keep on truckin

[DocCannabis]

either it was a loose wire or what mojoe said, coil/wire with moisture in it. switch back and see if the problem continues. if not, keep on truckin

Yup! Got the coils switched back, pulled and cleaned the plugs, put everything back together and it was nearly midnight here so I figured I'd give a break until morning before I try to start it! More to come tomorrow!

Appreciate the help dudes!

[DocCannabis]

Well.... I think my coils are shot... Got it all back together and just don't seem to want to fire, at all.... So I'm on the hunt for coils....

Do Post Ign Coils work on Pre's??


Never mind! Just ordered a set off a 97

[92xjunker]

Before you spend your cash, did you check the voltage to the coils? It has to be over 10.5v to fire properly. Test the voltage while trying to start.

[TRPUT]

Y

Swapped the coils, they both arc decently on all wires...

That kinda says it ain't the coils.