Hi just picked up an NC29 for the missus (and me if she lets me ride it), lovely looking bike, have a butchers on a hello thread, I put some pictures on;

http://www.400greybike.info/newforum/vi ... 826#p75826" onclick="window.open(this.href);return false;

Bikes fantastic, started from cold easily and took up and down the road without noises and rattles. Fantastic little bike. No problems on the ride home.

Took it out a day or two later to take the better half to have her first go on a bike in a car park and she loved it.

Anyway, got it out on Sunday, Squirrel Hunter from on here was around, for my sins I know him from another place, we fired it up and heard instantly that it wasn’t right. Only firing on three cylinders.

No heat on the downpipe coming from no 1 cylinder (? The left most cylinder) so it’s that one.

Not had a chance to take the tank off yet to have a look but I am thinking/hoping it’s just the HT lead.

I spoke to the bloke I bought it from, and have no reason to doubt him, seemed like a really nice fella who’s given the bike a good going over and stripped, cleaned and balanced the carbs also and he said he checked the sparkies and they were in good nick, he could see nothing out of the ordinary while he was in there and it was running fine when I tested it, rode it home and took it out again days later. He had also replaced a few of the pipes with new one due to them perishing but he’d not done anything with the HT leads so I’m guessing they are the original 19 year old ones.

I left the engine running for a minute or two but it stayed on three cylinders.

Am I right in saying this model has two coil packs feeding two cylinders each (1&4 then 2&3), so I don’t think it’s the coil pack or it’d be running on two cylinders right?

The sparkies SHOULD be alright but once I get the tank off I’m going to check the spark from cylinder 1 and 2, change the sparkies over and test again and if cylinder two lead still sparks then it’s not the sparkies so I’ll swap them back otherwise a new plug into cylinder 1.

For what it cost I have bought a length of HT lead from these guys http://www.bitzforbikes.co.uk/" onclick="window.open(this.href);return false; so I’ll just replace the lot anyway while I’m there and hopefully that do it.

Anything else? I read a thread on here that some fella had a similar problem and it turned out to be a loose connection on the wiring loom. I do have a multimeter and no idea how to use it

Any help appreciated.

Looks like you know where to start anyway, id have a guess at the spark plug. At least its the easy one to get to as the middle ones are buggers. Whip it out, check its condition and gap and see if your getting a nice spark then go from there.
Lovely bike by the way.

Chris.

to get near the sparkies you need to:
remove tank
remove air box
get 4 nail varnish colours and dob a colour on the end of each HT lead going in to the coil + on the coil that the lead. this way you cant screw up where each HT lead goes.
NOW unscrew the HT leads from the coils,
remove coils
pull rubber skirt toward the head stock and use duct tape to hold in place.
NOW you can just about reach the plugs...

small hands are a bonus with this job! i always start with the far left plug as its the hardest one to get out!

Alright guys, I think I may have jumped the gun when I ordered the HT Lead. On the phone, the bloke said it's all same stuff so I can use it for the Thundercat or the BlackBird if needed, I bought 4 meters of it for what it cost as I could sort out the other bikes then if had a problem with them.

Is there any particular way to attach it the socket that goes over the plug? I checked it against the coil I have for the Thundercat just lying around and same thickness but the end of one of those leads seems hollow where it gets pushed in to the rubber socket that goes onto the spark plug and the lead I have got delivered semms like a copper? core. Will try and get some pics but have to go out now.

I was foiled with the CBR immediatly, I couldn't get the tank off

I turned the fuel tap off and the tank doesn't just pull off because the fuel tap fouls the frame, there is a big nut that holds it on a 'funnel' that is part of the tank underneath. It looks like a fair sized nut anyone know what size (24mm??). My biggest spanner is 19mm and that's not big enough and I can't for the life of me find my ruddy adjustable. SO there we are, foiled at the start

the tank will come off with the tap on but if your finding it difficult there is a small philips screw inside the fuel tap handle undo this and the tank will slide off easily

If you take that nut off I'll bet you a pretty penny you'll empty the fuel tank rather sharpish.

Take the tap handle off as scratchin says, but make sure you've turned the fuel off first and remember there will still be a fair bit in the pipework that will be a pain to separate the first time.

Stretchie - stop with the whole fuel tap thing!

There's no need to remove the fuel tap at all to get the tank off. Whilst the original fixings are often renewed at some point, in standard trim, a 6mm allen key got the seat bolt, 8mm hex for the front bolt and thats it (you may need to pull the fuel line off first (you can sometimes spin the tank and rest it on the back of the bike without disconnecting the fuel line, but there's a risk of the tank falling on the floor....

Lift the rear of the tank slightly, draw it back so that the front tank mounting clears the mirror brace. Tilt the right hand side of the tank, and the fuel tap will roll around the frame as you safely lift and remove the tank. Don't mess with the fuel tap - they are fragile and parts are becoming rare and expensive!

Okay, its my thread you read, caused me immense grief, presuming you have now worked your way into the HT leads (cant recommend balancing tank, as if you have anything like my luck it wont be the same shape when you come to fit it back, undo the Phillips and all will be well, stay away from the rest !), the replacement lead needs to be 7mm otherwise it just won't fit, to replace them you screw the ends off the coils and pull the plug caps, the lead is on a spike but at the plug cap end its also a screw so twist the lead as you push it home, there needs to be quite an amount of lead in the coil to get it contacting 1" ish youll see from the marks on the originals.

Read the haynes manual for testing coils it could be that just one cylinder is out even though the other is fine as they are seperate windings for the secondary circuits !

check your plug gaps whilst your in there aswell as the general condition of the plugs, if non of this works get in touch and I'll tell you where to hunt in the loom !

Good Luck

Cheers guys. It's quite obvious about the fuel tap really..

What a I am

Thanks for the tips, I'll update you soon enough

detach fuel line from tap
on "side stand side of bike" slowly lift the front of the tank till the bolt hole touches mirror bar.
slowly lift rear of tank and at same time move tank away from you clearing the tap away from the frame.