5 year service parts

All fuel hoses and all oil hoses. These should all be in fire sleeve. All 17mm and 25mm (1 inch) coolant hoses, the 90 degree 17mm coolant hose on top, the rubber engine mounts, rubber diaphragms in the carb domes, the 66mm rubber hoses on each end of the carb balance tube, the carb rubber sockets and "O" rings, Make sure you use the proper clamps. Don't use the serrated worm drive clamps. These are old school and cut into the rubber and if over tightened will strip and lose their clamp pressure. Do not over tighten clamps as this can cut into the inner hose liner and cause debris. The four styles of clamps I use are Oeitker clamps (fuel hose), Wurth Zebra clamps (usually coolant hoses where the spring clamps are not used) (a type of raise rib worm drive clamp), Band-It clamps (for fire sleeve) and fuel injection clamps (for fuel or oil hose).

This may help on considering what or how to plan:

https://www.rotax-owner.com/en/rotax-blog/item/21-rotax-5-year-rubber-replacement-the-installation-considerations

Thanks Roger!

Is it really mandatory to replaces all the fuel and lubrication/cooling hoses??

Regards,

Barak.

Her's the issue. You aren't in a car where you can pull over to the curb if something fails. You endanger not only yourself, but passengers and people on the ground. Mfg's of these parts have done studies like Gate's hoses and show the years at where failure rates are more prevalent. Then you have to draw the line in the sand somewhere and you do it with the idea of protecting people with less factual researched knowledge. Most people will do these things to protect themselves and others. Sometimes you just can't protect people from themselves. Can and do hose last longer well yes they do, but at some point you're rolling the dice and you don't want to be one of those owners worldwide with any engine in any aircraft that goes down, has to buy a new engine, gets injured or dies.

Bottom line is it's ALWAYS better to error on the side of safety, less risk and danger then to push the envelope and wish you had just spent a day and complied. Many an engine has lost a hose over the many years in all aircraft worldwide.

t's just too easy to spend a day or two and just swap out the rubber. I have done a few hundred rubber changes over the years. I have seen may hoses on the brink of failure and talked to several that have lost their engine. FAA in the USA has reports of failed hoses in flight that caused crashes.

Better safe than sorry and like I always say; Don't strive to be average because there are way too many like that, but strive to be a cut above.:) 

Safe Flying to all.

Dear Barak

The Rotax requirement is for all the "rubber"hoses and some parts to be replaced at 5 year as a preventative measure.  The manual cant predict or know what other hoses, materials, an OEM or kit builder has supplied or purchased in the build other than what Rotax supplied with the engine.  A responsible OEM will provide you with their own maintenance manual that should contain all the data for what they have supplied and the airworthiness requirements for them.  

Components on the engine from Rotax are easy to define, such as the carburator attach sockets and rollar diaphrams inside the carbs.  The cooling hoses also are in the engine supply and should be replaced.  The tricky parts are the fuel lines and oil lines.  Rotax does not supply as part of the scope of delivery any oil lines.  Therefore we should assume that the OEM or builder will define this in their manual.  If not Rotax says you should change them at 5 years also.  

Fuel lines are the same.  if you have the Rotax supplied ones they have been made from a special materials with a hard outer skin that is fire resistant.  These orange lines, as stated in the maintenance manual line from Rotax, only require visual inspection for cranks or damage.  If there is no visible damage you do not have to replace them.  The problem is when you have old "rubber" lines, even if they are inside of firesleeve, these should be replaced.

The question is it mandatory?  This depends on the aircraft category you are registered under and the authority who oversees airworthiness in your area.  if it is in the USA and experimental you can ignore all requirements and make your own judgement.  As long as you can sign your annual condition inspection yourself that would work.  Is it wise?  Most likely not in my opinion.  If you are flying under light sport within the USA you have to follow the OEM maintenance manual.  If the OEM states in that manual you must follow the Rotax requirements then you have to follow that requirement.  Oddly certified aircraft, ones with a full TC, can avoid that but only for private aircraft and not commercial use.  The tricky part again is who will sign the annual off without you following the manual.  

Cheers

Thanks Roger for the detailed answer ..!

Now i have better understanding of the importance of this 5 year service..

Thanks again!

Barak.