ST4S Spark Plugs - Ducati.ms

st4spokane · Apr 12th, 2006, 3:22 pm

Just an FYI and my opinion. I recently started my 03 ST4S after the winter. I had started it a couple times throughout the winter but had not ridden it. Long story short the spark plugs fuel fouled. I replaced the Champion plugs with NGK (R-2525-10). This made for a unbelievable difference. Even compared to before the original plugs fouled. The bike doesnt even turn over one time before it fires up. Very good investment and I would recommend to anyone looking to change plugs. The plugs came from sparkplug.com. They were $10 a plug cheaper than I could find local (still $27 a plug).

acpdx · Apr 13th, 2006, 1:38 am

Thanks for the info!

dharhay · Apr 13th, 2006, 6:30 pm

And there are many of us that use the NGK DCPR8E in the ST4s.

Dave Harhay

Johnny · Sep 2nd, 2006, 5:17 am

Hi, Just wondering if the original poster was still happy with the plugs. I do get winter starting problems even with a conditioner plugged in so would welcome any other plug suggestions for the ST4s

st4spokane · Sep 2nd, 2006, 10:33 am

Still a fast crisp start every time!

**Gearbox** · Aug 31st, 2007, 11:20 am

Just about to buy new plugs and wondered whether , after a year , the E2525-10's were still performing well.

I have looked at the alternatives for my 01' ST4s and drew the following (Original Champion RA59GC-Gold Palladium):-

Champion RA59PP (Double Platinum)
Champion RA4GHC (Gold Palladium)
Champion RA4HC (Standard)
NGK DCR9EIX (Iridium)

The R2525-10's were not listed by this particular supplier

What is the combined wisdom out there ?

SS904 · Aug 31st, 2007, 12:10 pm

+1 on the NGKs. I use the DCPR8Es. But also a comment. If you're in a climate where you actually store your bike over the winter, it is not a good idea to periodically start it. Just let it sit. Starting it creates all sorts of fun, just like the one the OP had. You will most likely not be able to run it up to temperature properly. If it's really that cold, you'll likely end up with condensation problems when you shut it down like the milky oil threads we see every winter. Leave it be, happily hooked up into a battery tender, with some fuel stabilizer added, and all will be fine when it comes time to take it out of hibernation. Just my 2 cents!

northworthy · Aug 31st, 2007, 1:16 pm

Quote:

Originally Posted by SS904

+1 on the NGKs. I use the DCPR8Es. But also a comment. If you're in a climate where you actually store your bike over the winter, it is not a good idea to periodically start it. Just let it sit. Starting it creates all sorts of fun, just like the one the OP had. You will most likely not be able to run it up to temperature properly. If it's really that cold, you'll likely end up with condensation problems when you shut it down like the milky oil threads we see every winter. Leave it be, happily hooked up into a battery tender, with some fuel stabilizer added, and all will be fine when it comes time to take it out of hibernation. Just my 2 cents!

I endorse that - my ST4s is laid up every winter here in Swiss Alps from end Oct through to start April. Gets new plugs every 6k mls (NGKDCPR9E) and is never fired up during its hibernation. Result - no hesitant starting, no milky way in the sight glass and no spark plug failures in-between services since June 2001.

st4spokane · Aug 31st, 2007, 11:21 pm

I did take the advice and let the bike just set in winter mode this last year. It fired up without any problems in the spring. Still a great plug.

**Gearbox** · Oct 16th, 2007, 8:14 am

I thought I would just advise that I have just taken the bike (MY 01 - ST4S) out for a good run after fitting Iridium Spark Plugs and I have to say that I was amazed at the improvement in driveblity.

I dont think they provide any more power but the engine now fires really evenly and this makes for a big improvement at low revs on a light throttle.
Whereas before it sounded like there was an occasional but fairly frequent "miss" on the firing the engine now pulls really cleanly and even my wife noticed it whilst on the back.

I know it was not just the benefit of new plugs because the bike has always reacted the same on the standard plugs old or new.

FYI they are NGK DCPR9EIX's and I highly recommend giving them a try , but please post a comment if you do as I would value a second opinion.