Spark Plugs

motoddrob

motoddrob

Hero member
Location
S/W Australia
A mate of mine just fitted a set of Iridium plugs for his GS Beamer. Headed from Perth down to my place, 420kays and raved about how much better his bm runs and used 1.5 litres less fuel after filling up at 250km and reckons I should fit a set to my BM. He's about to fit them to all his bikes and car he's so impressed with them.
I've heard that they don't work so well in Laverdas so anyone know why? I'm tempted to try a set in my BM. Bit expensive but suppose to be good for 100k kays.
 
Funny thing Rob I think the combination of Iridiums and Dellortos are the issue not the iridium plugs per say, as I tried them in the past and it was just a great waste of money, but now with my 81 Jota running on a set of Mikunis I have gone back to the Iridiums and this bike is running like a charm and I have done about 4000kms no cold fouling more than I can say for some of my Jotas older sisters!
 
What ignition systems are you both running.
I think the iridium plugs need a modern system, including coils.
 
I have used (when I can find them) Gold Palladium plugs (B8 or 9EV) from NGK for many years with no ill effects to the bike running.
Paul LeClair is the guy to ask about Iridium plugs.
He threw them away after a dyno test when they were robbing the bike of power, solved by putting standard plugs back in.
Do a search on the forum.
 
I think the problem here is accelerator pumps. Old engines that just squirt neat fuel at the plugs seem to eat modern plugs. Back in the day we used to import Used Laverdas by the container full from Spain and Italy, first job was to get them running and that meant making sure there were no Champion plugs anywhere near them. I could put a new set of champions in a triple and  they woiuld fail sometimes before i even got it running, they just could not stand being flooded. You could take them out, put them on a mega tester and at least one would be a dead short. strangely i now have a new  Audi Turbo, it wrecked 2 sets of Bosch Audi Plugs in 2000 miles. Audi eventually changed them for NGK and its now done another 20k on those plugs.
There is no rhyme or reason with plugs in my experience, find a set that work and stick with them.
 
motoddrob said:
A mate of mine just fitted a set of Iridium plugs for his GS Beamer. Headed from Perth down to my place, 420kays and raved about how much better his bm runs and used 1.5 litres less fuel after filling up at 250km and reckons I should fit a set to my BM. He's about to fit them to all his bikes and car he's so impressed with them.
I've heard that they don't work so well in Laverdas so anyone know why? I'm tempted to try a set in my BM. Bit expensive but suppose to be good for 100k kays.
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Seems bizarre that a simple thing like spark plug could produce those sort of benefits. I'm not saying it isn't true, but there must be a reason they work so well (in some situations).

I've used NGKB9ESs in my SF ever since Bosch changed from the old 260T2 designation. Even after modifying the engine from dead stock (upping measured comp from 8.8 to 10.5, 5C cams, degreed or stock, open pipe), racing, touring, commuting - NEVER had a misfire caused by a plug. I won't change from them unless I have a VERY good reason to do so.
QF
 
Iridium plugs are designed for todays' modern fuel management systems.  They do not particularly like being doused in neat fuel every couple of seconds when the engine is running, fouling and eventually total failure can, and usually does, result.

They are perfect for applications where ideal mixture is delivered all the time, ie, NOT on carb-equipped engines, especially those with accelerator pumps.  They then last almost indefinitely, many auto manufacturers specify change intervals of 100000km and more.  The iridium tipped electrode is very resistant to spark erosion, their main/only(?) advantage.

piet
 
mauricejota7604 said:
Hi Grant Sachse ignition.
I was chatting to a chap that bought that 750 the other day he said you were a nice chap, I lied and told him he was correct. :LOL: :LOL: :LOL: :LOL: :LOL:
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Good man!  (bigthumb)
Tony was good to deal with, and I hope he likes the bike.
 
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