Spark Plug Cap resistance range

I see this post is 7 months old with no reply. Apologies for the delay in the response!

It seems that Rotax hasn't provided the resistance value on the spark plug caps for the 912 iS, 915iS, or 916iS fuel-injected engines, though currently, they maintain the same 5K ohm value as the 912ULS.As for the 912ULS manual, it indicates a range of 4.0 kΩ to 6.0 kΩ, so the readings you've shared fall well within this range (for now).

To dig deeper, it might be a good idea to look into the resistance values of the ignition coil. You can find these values in the Rotax 915iS heavy maintenance manual, specifically in section 76-50-00, Page 25, under "DOUBLE IGNITION COIL — INSPECTION." https://www.rotax-owner.com/pdf/MMH_915iAC24Series.pdf

• For the primary side: 0.6 Ω +/- 0.6 Ω
• For the secondary side: 8.2 kΩ +/- 0.82 kΩ

Hi all

The PVL spark plug connector does have a value.  I however had to find it in the 912/914 heavy manual. (page attached for reference) given they are all the same part number it would appear you could use that for your checks.  it appears to be an oversight not having it in the iS manual.  The current manual is from 2023 and they switched all engines to the PVL boots back in 2017 I believe.  

Cheers 

Hi All again...I took the time to send in a request to add this information to the iS engine maintenance manuals.  It was an oversight and should be corrected on newer publications.

Cheers