My 4RT requires a new spark plug more often than my previous 2 stroke Beta.

By my analysis, it appears the iridium equivalent of the NGK CR6EH-9 is the NGK CR6EIA-9.

Has anyone tried these?

Getting longer life?

Starting any easier? (not that I'm complaining...such a great bike to start)

Cheers, Jim

Hi Jim, I use an NGK iridium plug in my SY250 (i know its not a 4rt, wish it was though!)and used one in my previous bike and i would swear by 'em now great starting, smooth running and fit and forget, which makes it well worth the original expense!

There are a few guys on here that use these plugs and all rate them very highly!

To get a match for your old plug try http://www.spark-plugs.co.uk this site is very informative indeedy! hope this helps.

Edited April 4, 200620 yr by lastplacebrad

We are using one in Chris's Gas Gas 125 and ir seems to be an improvement. Starting is easier and no running problems.

Quality site that, just ordered myself a couple of the Iridium IX plugs for my Sherco

If you are fouling plugs - switch to the CR5EH-9 (or equivilent). Also (probably more important) make sure to let the bike warm up without without blipping the throttle constantly. Cold plug + large doses of fuel = fouled plug. I run a 5 and it still seems on the ragged edge of fouling when cold. Plugs need to be at a proper temp to self clean the large shots of fuel that are needed to give the instant response that the 4rt has.

Just a note, and I'm not saying one plug is better than the other.

When doing the temp test on four stroke and two stroke machines in a trial, I noted some 4rt's were running a lot hotter at the header pipe than others, only difference was they had a equivalent plug fitted because they were cheaper than the recommended plug.

I also found this to be true on my own Sherco 4T, the bike ran cooler header pipe temps when using the recommended plug, and the temp difference was immediately noticeable, of course the recommended plug is three times the $