Moving right along on my project, belts on, etc. when I hit a snag. I ordered OEM Champion RG4HC because I didn"t want to deal with fitment issues. When i put the new ones in I couldn't torque them, and removing them was a bitch. Comparing them to the ones i removed, and son of a bitch they are different. See pics. I know about the socket problems and grinding mods, but my bike seems especially tight. There is almost no clearance between th e new plug shoulder and the wall of the tube. Should I just grind the kit socket paper thin? But be forewarned. Champion may not be the easy solution any more. Btw, how does that plug read to you guys? Thanks, matt
Matt, a regular problem most often on the horiz cylinder on 749/999s (same motor). In the UK you can get thin wall sockets that are designed to overcome this issue https://www.ebay.co.uk/itm/Sealey-A...996084&hash=item25cd92e843:g:3UUAAOSwjT9duZ2O. My advice, and that from many others, is to use NGK as they are better and more reliable plugs. Do you have the OEM tool kit that came with the bike as that has a plug spanner which may fit better. Also if you were planning to, don't use a torque wrench, they just need the sealing washer squeezing which is not that tight.
Thanks guys. I generally prefer NGKs, and have used them in my off road bikes. I just put some Denso plugs in the 1098, and they are fine. If I have to go the special spanner route, I will probably throw the NGKs in. But The tolerance between the plug and tube is so tight. That laser socket does look thin, and might work. But waiting two weeks to get it running would suck . I did grind the kit socket down, but I have to take a lot more metal off of it to even come close. Looking down the tube it looks like I need to thin down the bottom, say 6mm, around the circumference to have a chance. But i did find it notable (and infuriating) that they changed the plug design. Conspiracy to compel buying the $20 dealership plug vs the $4 version with the same part number? Perhaps. Thanks guys. Matt
Solved. Took a tip from this board and had a machine shop turn an old 5/8 SP socket. Took .030" off the bottom say, 12mm. Worked like a charm.
Do you guys ever replace your spark plug wires - sorry, your HT leads? I usually do it every few years on my cars; my 998 is 20 years old and I assume it's on its original wires. Trouble is, they're $150 each from Ducati... (It's funny how Australian English uses a mix of UK and US terms automotive terms. We use bonnet and boot and sump, but fenders instead of wings and plug wires instead of HT leads.)
it depends how particular you are when it comes to fitting original parts as there are several cheaper alternatives. Not sure for 998 but 748/916/996 leads were Lancia Integrale etc items fitted as O.E.M. Price was cheaper via Fiat/Lancia 10 years ago but much the same now.
So long as it's a brand I recognize (or a legit OEM brand) I'm good with it. Do you have the Fiat/Lancia part numbers handy?
as said, probably no price advantage now but might help you cross-reference. I haven't bought any for 10 years and feel sure will be superseded by now anyway.
Just a note of caution. When I bought my 998S a couple of years back it ran fine when riding it around a car park but once I’d got it home and took it for a longer ride I discovered it had an intermittent misfire which I subsequently traced to the front cylinder. Going over a number of things to try to disciver what might be the cause I discovered the front HT lead’s plug cap was 5mm shorter than the rear’s. These photos probably aren’t the best due to the angle but the HT cap with the 5 ‘rings’ at the top is the correct Ducati part off the rear cylinder, the one with the 4 ‘rings’ which was 5mm shorter in overall length is, as you can see, made for Fiat. As we all know, it’s a long way down to the plugs on these Testastretta heads. The shorter Fiat one wasn’t quite long enough to fully, and securely, clip over the spark plug cap but was merely resting against it. As to why the previous (and only) owner had need to have the HT lead changed is another tale but he, or someone, had gone down the route of trying to save money and it hadn’t worked. I replaced it (painfully) with the ‘genuine’ part from Ducati at €97 , ouch, but at least it fitted. With the Fiat part being just 25% or less of the Ducati part I fully understand why someone went down that route. Maybe it’s just the 998 heads this is particular too but I wanted to let you know as you stated yours is a 998.
does look like a "Testastretta only" thing Paul, well spotted. As said, Fiat/Lancia part was OEM on earlier bikes so would have been easy to miss the subtle difference.
Champion in your lawnmower, NGK in your bike. I once bought some Iridium plugs online for the 916 but mistakenly ordered a slightly different variant, suitable for 888. You would think they would be the same but had a 1mm larger hex section so required a different socket, given that it's already tight in the head with the existing socket I never used them. IIRC they had the same no. with a different letter suffix?
Can.. can I borrow some money? Thanks Paul, this is good to know. I will visually inspect the leads and then decide if they need replacing. Can I test them at all? I have a DMM so I can test for resistance, but I don't know if there's anything else I can do to check them out. Which NGK would you suggest? I plugged the Champion part number into Google and it gave me a ton of NGK options.
Don't know, I'm the idiot that bought the wrong plugs for my 916 but I'm sure there'll be one that's correct.
You can only really test them for continuity and resistance afaik. I'm not aware there are any issues with these breaking down over time (at $100 a piece one would hope not) although I have read that some replace them with Magnacor ones for 'improved performance'. ( I use ' ' for I question exactly how much the performance would be improved, but that could just be me being cynical and may open a can of worms). I used NGK CR9E - I don't bother with the Iridium version (or any of the other exotic variants) of these on bikes of this vintage ever since I put some in my 1999 748 and it really didn't like them, swapped them out for non-iridium ones and it ran much much better.
Check out Magnecor, I'm sure they will be available be in Australia. A pair of their KV85 cables for the 998 costs about £65 here. https://www.magnecor.co.uk/catalogue/
NGK DCR9EIX for the 916. Guy on fleabay selling them at 4.99 each https://www.ebay.co.uk/itm/284708607451?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649
