Spark Plugs: how big should the spark be?

Post by **ramonlv** » Thu Nov 04, 2010 6:59 pm

Quick question about the spark coming from the plugs? How strong or big should it be?

Mine seem like they can't be any thinner. Very fine and whitish yellow in colour. I notice a lot of people talking about a thick blue spark. Sometimes I get one blue spark, but once out of every 5.

How do I get the thick blue spark? I don't think there is anything wrong with the spark plugs because they're a month old and they didn't produce a thick spark when first fitted.

The bike's a NC30

banoffee · Post by **banoffee** » Thu Nov 04, 2010 8:20 pm

does the bike go start / go OK?

Post by **Lope** » Thu Nov 04, 2010 11:41 pm

You can check the coil connections and battery voltage. battery voltage should be around 14.4 over 2000rpm.

Post by **CMSMJ1** » Fri Nov 05, 2010 12:07 am

Doesn't matter what you see...it matters whether the bike works or not. Does it?

The plugs in NC30 are fickle sods...so if you've killed them then lesson learned!!

What made you want to check them for the "fat blue spark" anyways? Surely not just being curious?

Post by **ramonlv** » Fri Nov 05, 2010 8:47 am

You guys are like detectives! the bike isn't starting. I don't think the sparks are the problem but was wondering if it was one thing I could or should sort whilst i'm giving an overhaul. Or is it just the way the sparks fire. Even when the bike was running well, it would never start up instantly on pressing the ignition. I think I would like that

Post by **CMSMJ1** » Fri Nov 05, 2010 9:09 am

As has been said, the plugs are weak.

If you are struggling to start the bike and giving it throttle to try and make it go..then you'll be flooding it and the plugs will be more and more likely to die..

You can get them all out and get the tips in a hot flame - gas cooker rather than a lighter... This will burn off some of the shit. Clean them and let them cool down!

With the plugs out, turn the bike over to get any excess petrol out the cylnders..just give it a blast on the starter a couple times and leave it half an hour to evaporate. Refit the plugs, get a good connection on the HT leads and turn fuel on, choke on and then try and start it - no throttle..not a sniff..

If nothing, leave it a few minutes and try again.....

These little buggers can be tough to start, mine is a bastard, but they are simple too...so choke and no throttle works 99% of the time

Post by **ramonlv** » Fri Nov 05, 2010 1:25 pm

Thanks for the tips. I'm definitely going to do the turnover and evaporate thing. That sounds like a great idea. I've had problems starting it before. This time I think it's an air leak because their doesn't feel like enough compression is coming out of the exhaust and I took the carbs out a while back so they may not be properly seated and the rubbers that house them seemed a bit knackered as well.

Spark Plugs: how big should the spark be?

Spark Plugs: how big should the spark be?

Re: Spark Plugs: how big should the spark be?

Re: Spark Plugs: how big should the spark be?

Re: Spark Plugs: how big should the spark be?

Re: Spark Plugs: how big should the spark be?

Re: Spark Plugs: how big should the spark be?

Re: Spark Plugs: how big should the spark be?