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New Rotax Service instructions - Running Modifications


Roger Lee

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New Rotax Service Instructions.

Running Modifications

 

 

http://legacy.rotax-...i-912-020r7.pdf

 

Highlights:

New style cylinder heads with CHT probe on top.

How to wire a soft start to your system.

Honeywell oil temp sender out and new sender in.

The old engine oil pump will not take threads of new sender. Buy new oil pump or just re-cut threads.

New head tightening torque: 90 in/lbs + 120 degrees

New fuel pump.

New fuel pump gasket. (no sealants)

New fuel pump max pressure. 2.2 psi min to 7.2 psi max

5 year fuel pump replacement

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Roger,

Can you remind me on what logbook entry (if any) one should make for a Service Instruction? I have a SLSA.

 

Also, should folks with Dynon systems go into the configuration file and change the upper limit on the fuel pressure (assuming they have the new fuel pump) so the yellow begins at 7.2 psi? Any idea if Dynon will make this change in their engine monitor files?

 

Thanks in advance.

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Hi Dan,

 

No logbook entries or action is needed. This document is just to let you know of changes to parts or service related items when the time or need arises. It more or less supplements the maint. manuals before entries to them can be made and to alert everyone on new and specific changes. If you have the old AC or Pierburg pump I would leave the Dynon or other fuel pressure indicator at 5.8 psi max. I doubt you'll ever see high pressures with those pumps. If you install a new pump then yes you can change the Dynon max pressure in the menu settings. I have a new pump and it hangs around 4.5 which is normal for most. Some have seen 5.5. If you run an electric pump with the new fuel pump it should add around .5 psi. There is really no need to run both pumps and some of this thinking comes from old school low wing thinking.

I don't know if Dynon will make the change. I believe they leave that up to owners and aircraft Mfg's. It's easy to do and only takes a minute.

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Hi Eddie,

 

I'm sure the new addition of the 5 year pump change was brought about by thinking the diaphragm's material will go bad and start to fail, plus Rotax includes hoses with the pump which is on the 5 year rubber change out.

(You can buy pump only)

I'm kind of in conflict over this change. Pumps don't fail like turning off a light switch. They usually give plenty of warning by starting to leak when the diaphragm starts to break down. They fail open so on a high wing you are usually good to go as far as flying to an extended destination. Some people have had bad pumps for a while and never knew it.

Most pumps last many years past the 5 year mark. Personally I don't see a reason to change a pump unless it starts to exhibit signs of failing. The old AC fuel pump had too many failing pumps and this new pump hasn't been in service long enough to know about its longevity.

Rotax doesn't want to give you the choice, but the owner will need to make the finial decision. I'm all for leaving the pump and replacing when necessary. This will boil down to a personal decision.

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Hi Dan,

 

No logbook entries or action is needed. This document is just to let you know of changes to parts or service related items when the time or need arises. It more or less supplements the maint. manuals before entries to them can be made and to alert everyone on new and specific changes. If you have the old AC or Pierburg pump I would leave the Dynon or other fuel pressure indicator at 5.8 psi max. I doubt you'll ever see high pressures with those pumps. If you install a new pump then yes you can change the Dynon max pressure in the menu settings. I have a new pump and it hangs around 4.5 which is normal for most. Some have seen 5.5. If you run an electric pump with the new fuel pump it should add around .5 psi. There is really no need to run both pumps and some of this thinking comes from old school low wing thinking.

I don't know if Dynon will make the change. I believe they leave that up to owners and aircraft Mfg's. It's easy to do and only takes a minute.

 

Thanks Roger,

I do have the new fuel pump (this is my 3rd on the plane), and it's been working very well. Yes, 4.5 psi is normal at cruise. It will bump 5.8 psi at idle but never seems to go higher.

 

I used to have to use the auxiliary electric fuel pump because I was getting very low readings (well below 1 psi), but don't need to now. I do use it to pressurize the fuel system before my 1st start after a week or two in the hangar.

 

Thanks again.

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