Ignition modules and heating gun

I have the same issue here with my Bristell, I have been going ctazy cjecking all sorts. Inread the heat response, tried it myself today and it starts beautifully.

I then allowed it to cool down, then no start, heated it again, it started first attempt.

so tested and proved. What is going on?

I do not want to carry a heat gun with me , remove the cowling and heat the cdi boxes, 

surely both boxes have not started misbehaving all of a sudden and simultaneously.

Graeme de morton wrote:

I have the same issue here with my Bristell, I have been going ctazy cjecking all sorts. Inread the heat response, tried it myself today and it starts beautifully.

I then allowed it to cool down, then no start, heated it again, it started first attempt.

so tested and proved. What is going on?

I do not want to carry a heat gun with me , remove the cowling and heat the cdi boxes, 

surely both boxes have not started misbehaving all of a sudden and simultaneously.

Curious, How old is the engine and hours?

Sorry for your issue, but Tte starting circuit in the modules have gone bad and you'll need to replace both modules. If you'd like you can send them to Lockwood Aviation in Sebring, FL and they can test them for confirmation, but the answer will be the same.

p.s.

Ice pack around the modules for 25-30 minutes works good too.

Ha! Ha! - Graeme is in Australia

Bert Flood Imports, Melbourne, Vic https://www.flyrotax.com/dis/bertflood

These problems with CDI modules intermittently failing is likely due to cracked solder joints made with lead-free solder.  The European Union implemented a directive called Reduction of Hazardous Substances (RoHS) in 2003.  One of its more problematic elements was the outlaw of solder containing lead.  The replacement solders were much more brittle and prone to cracking over time than softer leaded solders, especially in products that undergo repeated hot/cold cycles.  This has improved somewhat over the intervening years with improved solder formulations, but it's still a problem in harsh environments like aircraft engine compartments.

If the circuit boards inside these CDI modules are accessible by opening the enclosure then they're probably repairable.  If they're fully potted in resin then there's not much that can be done except replacement.

Hi to All....

if you have to heat, or ice the modules, for them to work just replace them.  To continue to use known defective parts is just nuts in my opinion.  Why take the risk?  What are the serial numbers of the parts? CDI boxes will have the part and serial number lazer engraved on them.  If as you say they are only 5 years old request a goodwill warranty from your distributor.  I noted that you are in Spain so that would be the distributor from Italy and the Service Centre is in Spain, check the Rotax dealer locator at www.Flyrotax.com for location and contact info.  It cant hurt to ask.  Fill in a customer service information report before you do, they will want all the details of the aircraft and engine.  Be sure to include a copy of your logbook to show that you kept up with the maintenance also, it is a requirement of the warranty to submit that.  

Cheers