NGK (3521) CR9EIX Iridium IX Spark Plug, Pack of 1

Received high quality NGK iridium plugs as expected. Works perfect for my Yamaha FZ09 and she runs smooth as butter. Note: just use pliers to gently unscrew the metal top. You install without them for FZ09.

I had purchased my first set of these last year (2015) as a spare set of plugs to keep in my Yamaha AR210 twin engine jet boat. The OEM NGK plugs are known to have short life span due to the high revving of the engines in these boats. This is the first season I have them Installed in the boat and I am certainly not dissapointed. The engines start better and perform better. I will be using these plugs going forward.

Very good

I purchased these spark plugs for my 2007 Suzuki GSX-R 600. The owners manual recommends changing them every 7500 miles. I installed them yesterday and the bike is running well. I'm not sure of the benefits of the Iridium plugs over the standard but why not upgrade for a couple of bucks more per plug.

Installed these (CR9EIX) in my Suzuki Katana 750 and what a difference from the stock plugs which were CR9EK. CR9EK are what they call dual electrodes which run about $10 a plug. Then I read about the CR9EIX plugs and found these on Amazon for about $8 a piece. By nature the Katana is a cold runnning bike but these plugs made warmups faster and the bike runs smoother. Most would say that the ignition system can't support these plugs. I say check with the NGK website or the dealer microfiche. I got 19k out of the stock plugs and NGK says I should get double that with these. And as you know, a Sport Touring bike has many panels to remove and a gas tank before you can see the plug wires. These were worth the time and effort to install rather than the stock plugs. [...]

The difference in spark plugs might be psychological but both my Suzuki DRZ400 and Yamaha WR250R seemed to have a bit more power and run better when I put in the Iridium plugs. Anyway it took me an hour to remove the seat, covers, and tank, replace the plug, and reinstall everything on my WR250R so I want to put in the best plug possible and not worry about it for another 10,000 miles or so.

I replaced my original plugs in my '03 Triumph Speed Triple with these after reading reviews on the Triumph blogs. Instillation was easy and the size was perfect. I also changed the oil on the bike and used a K&N filter (see my other review). The bike starts up immediately, idles nicely, and the extra torque has now returned. Its like riding a brand new bike. I am very happy that I search the internet and found these. If you search the web, you will see that others have paid a much higher price for the same item. The deal on Amazon can't be beat.

Good plug performance for Kawasaki STX-15F. However, one of the plugs broke the threads off in the head of my jetski using a 1/4 drive socket and wratchet! I was using the 1/4 drive seat the sealing ring and heard grind metal sound soon as it snugged up and continued to twist and turn freely. When I pulled socket back out, the plug came with it except, threads we're twisted off flush in the head. This was a pain to get out. Once out, I found the same plugs at a local Advanced Auto for a dollar cheaper. Installed with no issues.

Very good performance recently I had a around 1263 km ride from Assam to South sikkim it was north east rider's meet for three day's . As sikkim is very cold place iridium help very much no miss in the bike while pulling in hill's.. I suggest every one to have it.

Su calidad es buena , excelente

4個の値段でわないから買う前確認してください、4個の値段で安いかなあと思って買ったけど1個しか届いてないです。1個の値段だと高すぎてがっかりしたは、二度と買わないから気をつけくださいね。

Cela fait le job pour un scooter 250 CC

Ho montato queste candele all'iridio sulla mia Yamaha FZ1 1000 a inizio stagione 2016 e ho percorso appena circa 6.000 km. Per quanto riguarda la durata non posso quindi ancora confermare che sia circa doppia rispetto a quelle standard, posso tuttavia confermare di aver notato che l'avviamento a freddo, anche dopo un periodo di fermo prolungato, è immediato e senza tentennamenti, dunque la combustione sembra in effetti essere migliore. I vantaggi in temini di potenza e consumi, se ci sono, non sono a mio avviso percettibili. Amazon impeccabile come sempre. Buon acquisto a tutti