Anybody using an alternative spark plug to theROTAX SPARK PLUG 297-656 used on the 912iS which cost $21 each?
Anybody using an alternative spark plug to theROTAX SPARK PLUG 297-656 used on the 912iS which cost $21 each?
Eddie Forward
Flying
SS7, 912iS, Garmin G3X
I'm still using the same NGK DCPR8E plugs (gapped to .020") I have always used in my engine. No plans to change to the "Rotax" brand plugs.
I have the same opinion on continuing to use Mobil-1 Racing 4T.
Thanks Larry. I happened to note that those NGK plugs are what is in the Rotax Parts list of Old. Not that old but they have since started putting their name on the side of what is likely the same plug. I have just ordered my new NGK plugs from AS&S.
Eddie Forward
Flying
SS7, 912iS, Garmin G3X
Yeah, I would like to have their bank account as a result too. That is likely why they have $150K available to do the work in the first place. When NGK plugs were the prescribed plug and all was good, why would I need to pay 5X the price because it is labeled differently? Rotax is obviously not differentiating between what they sell for their certified engine and what is fine in their experimental engine. I don't need to pay certified prices for my engine as it is not certified. No problem here spending money when it is warranted.
Eddie Forward
Flying
SS7, 912iS, Garmin G3X
Eddie, there are many, many of us staying with the tried and true NGK plugs.
Jim Ott
Portland, OR
Kitfox SS7 flying
Rotax 912ULS
In fact, I would argue that the new Rotax plugs are LESS proven and have the possibility of problems yet to show up, compared to the NGK plugs track record of reliability for umpty-ump years. I could be wrong, but I don't believe the Rotax plugs are just rebranded NGK plugs.
Jim Ott
Portland, OR
Kitfox SS7 flying
Rotax 912ULS
FWIW - According to a detailed look at Rotax documentation on this deal, The new plugs are designed to go with the new boots; however, Rotax also says that the NGK branded plugs are fine to use, till they are no longer available (from Rotax).
The NGK plugs can be found from many vendors dealing with motorsports like quads, snow machines, motorcycles, etc; and, they vary in cost from $2.52 to almost $5 depending on who you buy them from.
I am sure it is not possible to determine to what extent the actual engineering is different with the new boots and plugs other than the shape of the boots and the name on the plug. That information is internal company info that will not be shared, I am sure.
My suspicion is this probably has more to do with dueling lawyer over the aviation use of NGK products than anything else. No idea who makes the new Rotax plugs, however, it is not beyond possibilities that NGK could make them but brands them for Rotax. The branding basically moves some of the product liability to the entity who's name is on product from the manufacturer.
On a sidebar comment about plugs - no matter new or used or whatever brand, I have always checked the resistance of the center conductor ( should be 5K ohms on these) and ocasionally find a plug, not necessarily used, which doesn't meet spec. A high resistance plug will still fire; but, who knows when/if it will fail. New plugs are not necessarily without flaws.
Certainly a person is generally OK with Rotax branded parts (although they have had a few bad parts of their own in the past), I see no reason to switch to the Rotax branded plugs on our 912ULS.
Jim's comment about the reliability of the NGK branded plugs rings true.
Dave S
Kitfox 7 Trigear (Flying since 2009)
912ULS Warp Drive
St Paul, MN
Thanks Dave for this. 👍. Will be checking every new spark plug in the future. Added it to my iPAD notes on regular Rotax 912 ULS maintenance.Dave S- no matter new or used or whatever brand, I have always checked the resistance of the center conductor ( should be 5K ohms on these)
DesertFox4
Admin.
7 Super Sport912 ULS Tri-gear
Okay, a follow on to the issues. I pulled my plugs and found them to be the NGK plugs. This engine was delivered from the factory with these plugs. I first bought replacements at Aircraft Spruce and found them to be the incorrect model of the correct part. Only one model has the metal top that will unscrew and leave you with the threaded post that is required. It is my understanding that NGK chose to not accept the liability for aviation use so now they have a big red X over an airplane and a trike right on the box. Problem with this was they were still manufacturing plugs for an aircraft engine manufacturer so... they quit Rotax. So, either they have actually quit, or they manufacture the plug ( or someone else does ) and label it as a Rotax manufactured part and up the price 10 fold to cover the liability.
Eddie Forward
Flying
SS7, 912iS, Garmin G3X