M900 - DPR8EA-9 or DPR9EA-9?

[Taman]

Hi guys,

Was curious what spark plugs people with M900 used. In the guide on spark-plugs.co.uk it says should use DPR8EA-9, and I think that was what was in bike when I got it. Now I am using DPR9EA-9 but am getting a little backfiring at times and thinking about trying changing back.

Will it make much difference? Suppose should just give it a go and see what happens, but thought I'd check.

Best, Taman

[manc skank]

i was told to use the lowest number possible without problems, the hotter one dpr9ea could put a hole through your cylinders if the bike runs lean, so i was told.

[A Yerbury]

no the lower the number the hotter the plug dpr9ea -9 or dpr9ea-8 the 8 seemed a lot better in the cold, much more stable.
alex.
....I could be completely wrong tho...

[Albie]

Are you using Shell Optimax. Its makes so much differance honest guv :D






Mr Patterson has no connection with Shell or its other related businesses so there chum . OK :rolleyes:

[manc skank]

no the lower the number the hotter the plug dpr9ea -9 or dpr9ea-8 the 8 seemed a lot better in the cold, much more stable.
alex.
....I could be completely wrong tho...

nope you are right, me typing with out thinking again :rolleyes:

[A Yerbury]

you pesky kids with your non thinking typing ways! whether the £££s worth on iridium et al makes a difference I dont know? Tam you are injected so you should have non of the carb problems that plague us neanderthal oldskoolers, check all your flange nuts, but hey, a little backfiring is another mans "character" try riding behind a norton...
Alice.

[A Yerbury]

Albie why are you wearing clown shoes?

[steviej]

Albie why are you wearing clown shoes?






:D :D :D :D :D :D :D :D :D :D

[Taman]

So sounds like I shouldn't worry and just stay with the colder 9s rather than give the 8s a go. Just wasn't sure given they reccomend the 8s. Also have chaged exhaust, aribox etc, and wasn't sure whether this would mean I should go hotter or colder.

Think maybe need to take in for a tune to get checked out. Feels like something is wrong (maybe electrics, seems to just miss a beat every now and then) then again, maybe I'm expecting it to be more japanese!

Best, Taman

[A Yerbury]

a run on a dyno is probably the best choice and will put your mind at rest. did mine with a local fella but someone here will no doubt point you towards someone who knows their ducks from their elbows.

[Duncan]

If they recommend 8s then fit them.
9s are used on the smaller engine which have different combustion characteristics and require a different heat value.
A lot of R&D goes into things like plug heat values. If you could fit any one succesfully there wouldnt need to be such a massive range of plugs about and Ducati could stock just the one item.
Now what about changing your tappet gaps to different values, offset the injection curve, take the resistors out of the plug caps, put compression plates on the pistons, fit lightweight chain, bevel drive the cams?

[crust]

Also have chaged exhaust, aribox etc, and wasn't sure whether this would mean I should go hotter or colder.

Think maybe need to take in for a tune to get checked out. Feels like something is wrong (maybe electrics, seems to just miss a beat every now and then) then again, maybe I'm expecting it to be more japanese!

Best, Taman

as you've changed the airbox and pipes the fueling will be out and will need adjusting.

Cue - someone telling you they are self adjusting - err no exactly where is the gas analyser on a 900ie?

sorry m8, its off to a dyno for you, back firing is usually a sign of leanness so sooner rather than later would be best.

:) Crust

[Taman]

Had dynoed when changed exhaust and airbox to have the Power Commander 3 mapped. Would have had the 9 spark plugs in then. It's not backfiring much just a bit curious. I actually think it's potentially a problem with a broken wire or alike that's messing up the fuel injection, but given I don't really know what I'm talking about, it's probably time I take it in to Baines or someone to have a look for the peace of mind.

Thanks for the tips!

Best, Taman