The fakes terminal cap shape is pretty accurate, however cast mold lines are visible, unlike the genuine plug.

NGK Iridium Motorbike Spark Plug CR9EIX9 | Halfords UK

If the engine is running dangerously lean the whole plug tip will be grey or white. If the temperature is over 850-degrees, pre-ignition may occur. Engine power will be reduced and you risk piston damage. A spark plug electrode is litterally at the absolute hottest part of the engine. It is where combustion starts, when compression is the highest it's going to be, and where a lightening bolt (that is a plasma discharge) is purposfully formed. Iridium IX Spark Plugs are the most technologically advanced high performance plugs available. Featuring a 0.6 mm iridium center electrode tip, they offer superior ignitability without sacrificing durability. The tapered ground electrode increases flame kernel expansion, while the superior heat range design is ideally suited to the demands of high performance environments.Bill I can get you a set of Denso plugs,but I don't think they are anything special... The thing is the cheapest I can find is 44 € ( 11 € each),which is really a normal price here in Greece,since the CR9EIA retail at 15 € each... Torque the spark plug up to your manufacturer’s recommended settings. If you don’t have a torque wrench, then get the plug hand tight and then add a ½ turn for a plug with a gasket, and more like a ¼ turn for a tapered spark plug. Over-tightening can snap the spark plug – a nightmare. Copper is generally seen as being the best metal to use in terms of conductivity but iridium plugs are seen as premium as they last longer than standard plugs and can be built with smaller tolerances. Iridium spark plugs also have lower voltage requirements, meaning they perform better when starting and idling and some manufacturers also claim they offer a better throttle response.

NGK Spark Plug Upgrade Chart - NGK Partfinder NGK Spark Plug Upgrade Chart - NGK Partfinder

Iridium alloy has extremely high melting point, perfect for today’s high-tech, high-performance engines A spark plug fouls with every single power stroke of the engine, as the fuel burns a deposit of soot forms on the electrode. Form enough deposit, the gap resistance changes and the plug either is resisted out or shorted out, neither of which will fire the cylinder. The metal in a spark plug has a single purpose: to channel the electrical energy through the spark plug. Iridium is far harder than copper and this allows the spark plug manufacturers to create a plug with a sharper ‘tip’ which better focuses the spark around the centre electrode without compromising its service life. Designed specifically for the performance enthusiast Iridium IX offers extreme ignitability, improved throttle response and superior anti fouling. If you’re going to be doing any sort of work on the bike, treat yourself to a decent set of tools. Most of mine are from the Halfords Advanced range (formerly called Professional).This is why you can't 1. hurt your engine with the wrong plugs... you can only hurt your plugs. and 2. Plug slection has no affect on engine performance or horse power... If your plug is fireing during every power stroke... that's the best it can do. Fatter spark, bigger spark, super jiggy spark Doesn't matter... if the fuel/air mix is being ignited every time... that's as good as it gets. Mind you, there are 1000 things that can mess with "fireing every power stroke" but you won't get more power using a "hotter" plug. Maybe it's time for a little spark plug 101 as it was explained to me by a guy who didn't spout any BS. M&P Direct Ltd. is registered in England and Wales No. 03928542. Phoenix Way, Garngoch Industrial Estate, Gorseinon, Swansea, SA4 9HN. VAT No. GB 779 463 275. If the plug is brown or light grey your can assume your engine is in good condition and the spark plug is functioning well. Even when a plug is in good condition small deposits will accumulate. This is normal. Rich

NGK Iridium Spark plug CR9EIX (3521) | Sparkplugs Ltd

Just put iridium plugs in my K5 and it seems to have cleaned up a very slight light burble of a misfire that I had. It gets better, the installation guides on the rear of the inner boxes are for an M14 (14mm) diameter threaded spark plug, not M10 (10mm) that CR9EIX features! If you need to change your Kawasaki’s spark plugs but you’re not sure of the size or if you want to upgrade your plugs to an iridium version for a longer-lasting plug, this is the guide for you.Iridium alloy has extremely high melting point, perfect for todays high-tech, high-performance engines A regular spark plug uses a copper central electrode whereas an iridium spark plug uses, you guessed it, iridium. PLEASE NOTE – This article was written a few years ago so not all information provided may be accurate. For example, on some part numbers, NGK now uses Laser Etching instead of stamping, so the font information may not be accurate. Another Sparking Discovery Fake plugs are known to have air bubbles trapped inside the white ceramic insulator which can affect heat dissipation capability. And so, if your plugs are working, they reach the self cleaning temp, your wires are not leaking, your plug caps are properly connected and intact... you are good to go.