Which spark plug is right? - Ducati.ms

MitchB · Dec 14th, 2011, 12:08 am

I have a '81 Darmah. Now fitted with 5 ohm DYNA Coils.

The bike had NGK B7HS plugs in it. New plugs from BevHev are NGK BP6HS

What's the difference..?

Duccout · Dec 14th, 2011, 11:49 am

I think it depends on how you ride; the BP7's are for hard riding and the BP6's for more gentle pursuits.

DesmoDog · Dec 14th, 2011, 12:34 pm

Part number decoder is here:
http://www.ngksparkplugs.com/techinf...tnumberkey.pdf

The difference is the BP6 has a projected insulator and a hotter heat range.

What that means to you, I'm not sure... but that's what the differences are according to NGKs site.

wdietz186 · Dec 14th, 2011, 1:59 pm

You will be fine with the BP6 plugs. The extended tip will not interfere with the piston and it will burn a little cleaner/be less prone to fouling.The colder plug will fluff up more easily in low speed riding especially if the engine is typical for an old bevel[loose valve guides,marginal voltage to coils,rich mixture,etc.] I don't think anybody really hammers their bevels enough to warrant a colder plug these days.

MitchB · Dec 14th, 2011, 2:55 pm

Well now, that's a handy little chart to have...

Thx, Craig

Passinglane · Dec 14th, 2011, 5:23 pm

Recently my SS fouled B7HS plugs so I stuck in an old pair of Champion L86Cs. No further problems - I've always found these plugs to work well for me. I will admit that my bike needs new valve seals which probably caused the problem in the first place since the 7s aren't hot enough to burn off the crap. B6HS plugs should work as well.

Bruce

MitchB · Dec 14th, 2011, 5:48 pm

Guys, thx for the inputs.

I'll stick these new NGK BP6HS in and keep an eye on them. I'll stick the "7's" in my "Bevel Drawer"...

RockingM · Dec 14th, 2011, 6:32 pm

btw, for a few dollars more you might try the BPR6HIX iridium. $8 each at Advance auto or similar stores in your area. Steve also carries them.
I just put a set in my 750GT.

machten · Dec 17th, 2011, 4:46 am

Quote:

You will be fine with the BP6 plugs. The extended tip will not interfere with the piston and it will burn a little cleaner/be less prone to fouling.The colder plug will fluff up more easily in low speed riding especially if the engine is typical for an old bevel[loose valve guides,marginal voltage to coils,rich mixture,etc.] I don't think anybody really hammers their bevels enough to warrant a colder plug these days.

+1 on Bill's comment. I think the 6 range also helps a bit with burning off valve lubricant deposits if you use it.

Kev

MitchB · Dec 17th, 2011, 11:49 am

Well the bike fired and seems to run fine - after sitting for over two years and an unknown prior history...

Carburates fairly well. The clutch was stuck, but freed with a little coaxing. Adjusted now, so it doesn't slip.

So - I took a quick spin around the neighborhood to check shifting action. All seems OK. Handling felt very...wooden..unrefined. Back in the garage - checked pressure: 14 psi in the front / 22 in the rear... So that should help -

Major step(s) toward getting this bike back on the road.