A larger gap will give different temperatures for your bike. Becuase of a larger spark, the fuel ignites more/differently and the large difference is in operating temperatures. Always fit a recommended plug gap, since that is what the engine was designed for. Sometimes if you have modified the carby settings, a park with a different reading will either cool down or warm up the bike. At extreme differnces in plug gap, bikes run very very lean or very very rich. I suggest trial and error on this one, but really you should stick to factory plug size....

 

Every Ducati I've run likes a wider gap. The -9 plugs with the .9mm gap seem to work very well. And I'm quite certain you won't be able to measure any temperature differences with the engine.

Chris

 

I have Iridium plugs in my car's engine, and if you look carefully at the electrode, you'll notice that it's TINY compared to a standard plug. The reason that they say do not gap is for fear of damaging the electrode. If the gap is not right, just buy a plug with the correct gap. Honestly, the ones that I bought for my car had a slightly different gap than the manual suggested. It didn't matter, the car runs amazing with those plugs and I strongly recommend them. The ones I bought were Denso Iridium plugs, and I want to find some for my 2001 Monster 600. Does anyone know the part number??

 

Hi everybody,

I bought some ngk dpr8eix-9 iridium spark plugs for my 98 monster 750

I just installed some iridiums this weekend.

 

I have a Ducati M750 2001 and I also bought those plugs. The one thing that is confusing me is on the user manual, it says the gap must be .6 - .7 mm. But like you all said, the factory preset for the NGK is .24.

Should I go with that or should I change?

Please help!!

 

Factory preset is .024" not .24mm
Chris

 

FYI NGK part # is DCPR8EIX.

 

Chiming in here...

I have had the NGK Iridiums in my bike since it had about 150 miles on it because I read somewhere that they helped smooth out the engine at lower RPM. The other day (with over 16,000 miles on these plugs) I was reading some info from this guy: http://www.ducati.ms/forums/showthread.php?t=31417&highlight=iridium+spark+plug

He says that the iridium plugs work better with a larger gap, much larger than the stock Ducati spec.

Based on that I opened up the gaps on my plugs by about 0.01" and sure enough, smoother throttle, no hiccups, runs better than ever. I may try to open them more next time I'm poking around with stuff....

 

If Chris .9mm (.354"), you can bank on it. [thumbsup]

I think I'll try a set.

LA

 

FYI NGK part # is DCPR8EIX.

The NGK's pulled out of my '97 M900 were part # DCPR8E.

Is that the "normal" plug?
If not, what is?

I haven't checked my cycle yet, tonight I will.

 

I think the IX= Iridium...

 

NGK website http://www.ngksparkplugs.com/part_finder/motorcycles/default.asp?mode=nml

 

Why does no one stock these!?!?!?!

 

I= Iridium
Heres good one http://www.spark-plugs.co.uk/pages/technical/ngkjpg.htm

 

FYI NGK part # is DCPR8EIX.

That is the plug part number for the standard gap...what is the plug number for the slightly larger gap?

 

That is the plug part number for the standard gap...what is the plug number for the slightly larger gap?

There is a dash then a number at the end of the plug part number that identifies the gap. I "borrowed" the following from adamo from another NGK thread:

-8 = .032" std. gap, -9 = .036" std. gap, -10 = .040" std. gap, etc.

The -suffix is just the conversion factor from metric, i.e -9 is .9 mm gap or .9 times .040 gives you the equivalent inch measurement of .036".

So, a Ducati plug with a 0.032" gap would be part number DCPR8EIX-8. So far the only size other than stock 0.24" gap that I've been able to find is DCPR8EIX-9, or .036" gap and that seems to be what Chris at CA-Cycleworks recommends (hope I'm not misquoting him).

 

Stock plug for my Monster is the NGK DCPR8E (4339) gapped at 0.024mm. This plug utilizes a terminal stud (threaded) and 16mm hex size.

The iridium version is the NGK DCPR8EIX (6546). This plug is factory gapped at 8mm (0.032") and utilizes a 16mm (5/8") hex and a non-removable solid (nut) terminal. Because of the solid terminal, YOU CANNOT USE THE STOCK CAPS (BOOTS) WITH THESE PLUGS.

An NGK spokesperson recommended trying the NGK DPR8EIX-9 (2202) instead. This plug is factory gapped at 9mm (0.036") and utilizes an 18mm hex and the correct terminal stud (yes, you can use your stock caps). BECAUSE OF THE LARGER (18mm) HEX, YOU COULD HAVE DIFFICULTY USING A SPARK PLUG SOCKET WRENCH.

I looked at my heads and it appears that the 18mm hex will fit fine. And, as others have noted, running a wider gap is recommended with the iridium plugs.

 

Oh, speaking of spark plug caps (boots), if you want to use the NGK Iridium DCPR8EIX (6545) plug in your bike, you'll need to replace the stock spark plug wire caps (this is because the stock caps fit stud terminals, but the 6545 uses a terminal nut).

The stock cap is an MTA 1900900 (fits terminal stud). The MTA 1900930 fits a terminal nut.

Anyone know where to buy MTA parts?

 

Newer monsters use the terminal nut, not a stud.

 

Stock plug for my Monster is the NGK DCPR8E (4339) gapped at 0.024mm. This plug utilizes a terminal stud (threaded) and 16mm hex size.

The iridium version is the NGK DCPR8EIX (6546). This plug is factory gapped at 8mm (0.032") and utilizes a 16mm (5/8") hex and a non-removable solid (nut) terminal. Because of the solid terminal, YOU CANNOT USE THE STOCK CAPS (BOOTS) WITH THESE PLUGS.

An NGK spokesperson recommended trying the NGK DPR8EIX-9 (2202) instead. This plug is factory gapped at 9mm (0.036") and utilizes an 18mm hex and the correct terminal stud (yes, you can use your stock caps). BECAUSE OF THE LARGER (18mm) HEX, YOU COULD HAVE DIFFICULTY USING A SPARK PLUG SOCKET WRENCH.

I looked at my heads and it appears that the 18mm hex will fit fine. And, as others have noted, running a wider gap is recommended with the iridium plugs.

Yep, best bet is to use the spark plug wrench that came with your bikes "tool kit".