80 HP 912UL will not start

Re: 80 HP 912UL will not start

by Andy Fell » 10 years ago

Andy Fell

0 17 0

I sent my ignition modules to Carmo in the Netherlands.

It took about a week to get them back (to the UK). Plugged them in and the 912 fires up perfectly. In fact, it seems to fire up better than it has done for a long time (never realised the start-up spark had got so weak). They cut out the back, repair 'something' and then pot the module from the back, thus making it completely sealed now.

I have been working with another guy in the UK here to try to figure this out (along with Kevin's very useful information). There is a heat dependency and clearly some component is 'on the edge' of its design margin (which is temporarily repaired by application of heat) - we have speculated it could be NPN hfe sensitivity or one of the SCRs having a weak gate threshold (but other evidence contradicts this at times).

We got to the point where it needs quite a lot of effort to really get to the bottom of (certainly doesn't seem simple on the face of it), in which case spare time return on investment is low! Keeping our noses to the ground if any more gem information arrives.

Re: 80 HP 912UL will not start

by Kevin Stewart » 10 years ago

Kevin Stewart

5 184 0

Andy,

Glad to hear that you have had yours fixed. Which area on the back of the module did they cut open?

If it was just a small area then it is probably possible to identify the component causing the trouble.

Kevin

Rotax912IgnitionModule.png (You do not have access to download this file.)

Re: 80 HP 912UL will not start

by Andy Fell » 10 years ago

Andy Fell

0 17 0

If only, Kevin :-)

I think these guys are guarding their secret carefully; who would blame them!?

The whole back was cut open (say, 2mm edge left all around the back) and then entirely re-potted. I can see no evidence through the potting of the modification/fix, the potting is the very black stuff! There is no raised section in the potting, so it seems that the fix is 'subtle'.

Re: 80 HP 912UL will not start

by David Wallis » 10 years ago

David Wallis

2 13 0

I was thinking of getting my dead modules fixed even though I bought new ones. I hope this isn't a violation but can you post more information about CARMO so I might contact them?

Re: 80 HP 912UL will not start

by Kevin Stewart » 10 years ago

Kevin Stewart

5 184 0

Well Andy, get in there and dig it out! I'm curious now ;)

Here's the link David to the Carmo web site:

Carmo web site.