Bimota Forum

[shay001]

Guys, I have a dead plug on my DB1, but that is not the actual problem. The online NGK data site says B7HS or BPR7HIX. Now that should be easy, but it ain't.

These plugs will not physically fit into the cylinder head. They have a wider diameter and not enough reach.

What has come out is marked BPR8EIX-9, but I have no way of knowing if this is the correct plug, the bike was badly mistreated by the previous owner who seemed ready to do an insurance job on it. The frame no. 00086 was pretty well ground away.

In any case, it has come to a good home, will be exercised regularly and well cared for.

Any assistance in this issue most welcome

[shay001]

I think I should elaborate as to the reason for my confusion. The plug in one cylinder was marked DB8EA, and the other was DPR8EIX-9.

Both NGK, but given the different numbers (although clearly the DPR is iridium) and they have a similar (same?) heat range can anyone give me a recommendation as to what works best?

[2bims]

i'LL DIG OUT THE RIGHT codes for DB1....and even your Ducati dealer could help...same engine as Ducati 750F1, Montjuich and Santa Monica....I'd steer clear of iridium plugs...extra cost, modern plug....old engine...old design.....not worth bothering with

[2bims]

Best to check the Plug cap...and plug lead also...i.e...interchange plugs....with the age of the bike they can give up the ghost from time to time....remake the end of the plug lead etc etc...

[shay001]

yes, checked all that out, the system is fine, the plug is stuffed. It's Saturday morning, I'll make some calls

[shay001]

correct plugs for this particular engine are NGK DPR8EA-9. Trouble is that it is still a pig to start, flooding, backfiring yet at other times starts like a dream.

Beats me, maybe just inherited from the nature of Ducati engines from those days.

What's that saying "Ducati, turning motorcyclists into mechanics for 90 years"

Suffice to say, no old Ducatis in my collection

[stratos23]

Hi Shay,

As 2Bims suggested - -just use std F1 plugs like NGK DR8EA's.

A hard starting and bad running DB1 can be super frustrating, since getting at anything is a mission if the body work is on - as I'm sure you've experienced!

I cured similar issues on my F1 with a new set of Dyna mini coils (BIG spark) and by replacing the wiring that runs from the pick-ups, out through the left side crank case and up to the CDI's. What happens here is these wires run through the engine oil before exiting the casings through the gland - so eventually, insulation on the wires just breaks up and things start shorting. The old rubber insulation just can't take the heat. It happens eventually to ALL old Ducati engines.

Nowadays you can get a good heat/oil resistant wire - which I used when I did the job. You need to use an epoxy around the pick-up area to prevent the wires being picked up by the flywheel. Bit of a fiddly job, but not difficult - and HOLY MOLY, my F1 starts before my finger even gets to the button these days. Must get round to doing the same on the DB1!

This all said, you may well have other issues feeding the problem - but these simple measures will eventually pay off in spades...

I get my Dyna coils for a very reasonable price from these very helpful people - ask for Jenny:

http://www.ebay.com/sch/bevelgear/m.html?_nkw=&_armrs=1&_ipg=&_from=
_________________
DB1 . Ducati F1 . Ducati TT2 . Ducati 450D . Guzzi LM1 . Morini Kanguro

[shay001]

yes, I think I'll give it a go. Had a 500 Pantah for many many years so I know where the pickups live, obviously the easiest thing is to do the coils. If you could post or pm me any details on the wire you mentioned that would be first rate.

I like riding this bike, but to truly have fun you have to be confident it will get you back home. This one seems cantankerous starting from not hot but warm, say after cooling for an hour. The carbs are not particularly worn, and in any case they have been totally stripped and re built. I was saw a 600 Pantah with the slide in the rear carb so badly worn you could hear it rattle, it still started and ran, albeit rough as guts.

The spark seems nice and strong, but of course under pressure may be a different story. When we tested aircraft spark plugs we always tested in a small pressurised chamber.

[stratos23]

Hmm - if the carbs have been rebuilt, then I'd definately look into the ignition. The only other likely area to check could be valve seating etc.

As for the wires - a friend with an F1 loaned me a whole roll of wire to do mine. I do know he got it from Radio Spares, but don't have a product code handy.

Bevel Heaven sell this kit, which includes the wires - but since it's only the wire you need, you could save some $$ by shopping around

https://store.bevelheaven.com/Electrics-Battery-Ignition/BOSCH-Pickup-Wire-Kit-SS-Darmah/

I do remember seeing a link on a forum somewhere. Just tried a quick search, but couldn't find anything.

I agree re the thrill of riding the DB1. I haven't had it on the track yet, but if it's anything like the F1, then I know it will be addictive. It seems a lot more rigid and quicker to turn in. I've only had mine a few months now (having dreamt about them since i was a teenager!). Roll on summer!!
_________________
DB1 . Ducati F1 . Ducati TT2 . Ducati 450D . Guzzi LM1 . Morini Kanguro

[shay001]

SUCCESSSSSSSSSSSS!!!!!!!!!!!!!!

Before, when it did start, I could not get it to idle under 1900. The plugs are now matched, gapped, battery PROPERLY charged and I cleaned the low voltage tabs on the coils with a suede brush (only lightly mind).

She roared into life, but not only that with some very minor tweaking is idling beautifully at 1100~1200 rpm.

Thanks for the help guys, I am going to dress the bike, change into appropriate attire (including my BIMOTA leather jacket) and go for a ride.