Light speed unit breaking down

[RV7aRalf]

Hi, I have an RV7a with 2 light speed units that provide power to the engine this system was working well enough for some time and then all of a sudden I am having problems with the engine missing and fouling spark plugs. The last engine run up the right hand unit was to me not working correctly and it was breaking down to the point that the engine was back firing and missing quite badly. I did various tests such as coils, spark plugs all wires the pick ups and I believe that I have narrowed it down to the control box. One of the boxes is one of the original units and the one that i believe has failed is a unit that is only a few years old and has only done about 200 hours of work. The unit does work usually whilst cold and as soon as the unit has been working for some time around the time that the run up would be done the unit seems to break down at that point. Can anyone give advice that could help me to fix this frustrating problem, thank you

[dwilson]

Hi,
I have a Lightspeed unit on one side of my RV9A. Had similar problems at run up after about 3 years and 650 hours. I replaced the spark plug wires with new ones from Lightspeed and the problem was cured.

Good luck!

[N427EF]

Similar set up and symptoms on my 8 some time ago.
After replacing all sparkplug wires and changing to the RG400 I finally found the problem. A slightly corroded spade connector on the coill that was intermittently arcing and causing the partial loss of ignition.
This problem was not obious and could not be detected by simply looking at it. Only when I pulled the connector off could I see the corrosion from the arcing.
If all else fails give Klaus a call.

[Ron Lee]

Several years ago I had a problem. My recollection of the specifics is marginal but I did work with Klaus to isolate the problem.

I think I even changed out the control box. In the end, I suspect some corrosion on the multi-pin connector to the control box (from the magneto area unit).

As mentioned above, it may be a hard to find but easy to fix solution. This past year I replaced all my plug wires as a preventive measure and since it was recommended anyway in the manual.

[RV-4]

Hello Ralf
I've had the same problems you're having last summer and I did the exact same steps you did until I finally called Klauss.

His first question was to know if I was using a direct crack sensor or one or two Hall Effets.

Having 2 Hall Effets installed in my set up, he told me to simply disconnect the connectors to the Hall Effets and to clean the contacts with an electrical contact cleaner which I did and I didn't have any problems since..It's working flawlessly...

Cheap solution and worth a try if you haven't done it yet. IMHO

Good luck

Bruno
rv4@videotron.ca

[RV7aRalf]

Thank you for that comment Duane, I have checked the ignition leads by swapping top spark leads to the bottom and there is no difference as the same unit seems to be breaking down. I wish it was that simple though.

[RV7aRalf]

Thanks Bruno, my system uses twin crank sensors, but I will also check the connections a bit closer now and give them a clean. The problem then is that the whole system is a bit on the temperamental side and perhaps it may require more stable connectors instead of the, what I can see are not that great a quality in the connection side of things.

[RV7aRalf]

Thanks for your input Ron, after speaking to the previous owner and he told me that he had a similar to what i now have and the way he cured it was to send the offending unit to Klaus for repairs. He upon getting the unit back replaced the then Slick mag with the Light speed version 3. Work great for him and now I am having the same problems but now with the new unit which only has less than 200 hours on it. I am seriously thinking of replacing the newer unit with original Slick mag. The Slick mag may be old fashioned but at least it is simple, could I be wrong about this?

[RV7aRalf]

Thanks Ernst, I have taken that on board and will have a closer look