fbpx

 

Hi guys...great site just signed up and happy to be aboard!
I live in Calgary and just purchased a Kitfox 4 with a brand new (8 months) Rotax 912S in it. I bought the plane knowing that there was an ignition problem, but was hoping i could trouble shoot myself and figure it out. I have owned 7 planes in the last 10 years and have rebuilt engines and restored vehicles on the side for years, so not an expert but relativity handy with a wrench...........
SO HERE IS THE ISSUE!!
I have no spark on or thru the 'B" module.....here is what i have tried and what I know so far:

- plane has toggle switch mags, i have checked continuity and switches are functioning as they should.
-as per the Heavy Maint manual---i have checked the resistance on both the 2 charging coils as well as
all of the pick up trigger coils, again all within spec. The PO actually just replaced the old pick ups
thinking that that was the problem....it wasn't. Checked the old harness and its within specs as well.(guess i now have a spare).
-checked the power output from the charging coils (red wires) and it registered approx 7 volts AC while cranking engine over (adequate?).
-again, engine is practically brand new, it has the yellow labelled Soft start modules.
-The PO has moved the modules on to the engine mount because of engine mount interference. He properly installed these using Adele clamps and vibration isolators. I have checked every ground wire, and they all seem perfect. Interesting thing is that he told me that the engine did run on the B module before he changed out the trigger harness, but it was rough. After the new one was installed....nothing at all.
-I have not checked the gap clearence on the new triggers....heres why:
When i checked the wiring i discovered that he had the modules plugged in wrong. So the Green/Black color coded wire terminals that run cylinders 1 and 2 bottom and 3 and 4 top were actually plugged into the "A" module. So as it stands now, the engine does run on the green/black harness but is feeding the "A" module instead of the "B". So of course its switched by the B mag toggle. This tells me that the Green/black triggers are doing their job, but when i plug them into the "B" module (the proper one) its totally dead.....so I'm thinking bad "B" module....RIGHT? when i take the other harness plug (blue/red)
and plug it into the a module (which i know works) guess what!!! NOTHING......???? but i know the A works fine........SO COULD THIS BE A DUAL FAILURE?????
Could the pickup triggers for red/blue either be failed or the gap set incorrectly? because that harness wont run anything....AND my B module is also fried? Green/Black again runs A just fine but not "B" the one its supposed to. What would the odds of this be?
I'm pulling my hair out here....trying to figure this out. The engine was purchased new in May of 2014,
at Rotax Research Canada In Vernon BC......would any of this be covered on Warranty????
What other trouble shooting procedures could I check to help me with this? I dont mind fixing whats broken but don't really want to buy a $1000.00 module if that's not the issue.
Sorry for the long thread....hope the details help! Thanks in advance....again GREAT SITE!

Cheers
Wade
  • Re: no spark

    by » 9 years ago


    Hi Wade,
    -Red stator wires: 7 volts AC is good at cranking rpm.
    -I think a ground is missing; the secondary coils and the modules are grounded through the six pin connectors. are you sure all of them are connected to a good ground?
    Rob

  • Re: no spark

    by » 9 years ago


    Rob:
    Thanks for the reply (was beginning to feel shunned...LOL). Good to know about the 7 volt ac output.
    I spoke with a Rotax service rep in my area yesterday. He said the same as you...sounds like a ground problem. He is going to come out tomorrow and help me trouble shoot somemore.
    I will post back the results of our find......stay tuned :)

You do not have permissions to reply to this topic.