Quote:
Originally Posted by rv3flier
What are the odds that two days after flying with no issues, that upon turning on the master sw, there's no clacking noise indicating that the Facet fuel pump is working. So, then I start the engine using it's fuel pump only and my oil pressure reads "0" ziltch, nada. Two failures at once and apparently unrelated.
Too bad the RV-12 design didn't include and isolation shut off between the fuel tank and the fuel pump. It makes a relatively simple job very time consuming.
Then, I find that Rotax has changed the supplier for the pressure sender and that, while the new Keller sender and it's wiring harness can be had from Aircraft Spruce in europe for $190, Lockwood wants $360 !!!! It feels like being held hostage.
OK, rant over.
Has anyone noted that the new Keller sender uses the bottom of its range of 4 ohms to show .75 BAR (about 11 psi) and not Zero like the old Honeywell unit. So, if you lose all oil pressure you'll still show 11 psi. What have others done to account for this?
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We saw this post and thought we could offer up some helpful information that was obtained from the Customer Service Department at California Power Systems.
There is a lot of confusion about the oil pressure senders on Rotax 912 series engines. Originally the engine came with a VDO sending unit, that sender was prone to failure and replaced.
Rotax started using the Honeywell sender and that was a very solid unit with few malfunctions. The Honeywell transducer produced a different signal than the VDO transducer, and the wires were permanently molded into the sending unit requiring rewiring to the gauge when the sender was replaced. Honeywell did not want that transducer used on aircraft so they stopped supplying it to Rotax for use on aircraft engines.
The newest oil pressure transducer is made by Keller, and produces the same signal as the Honeywell sensor, so no reprogramming of the EFIS is required. Another benefit of the Keller unit is that it includes a connector at the sending unit, so running wires to the gauge is not required when replaced the sending unit. One major difference between the Honeywell and the Keller is the thread size. The Honeywell has a 1/8" NPT thread and the Keller has a 10mm thread. This is important to know since you can get the 10mm thread to start in the 1/8" NPT hole damaging the oil pump housing. Rotax has published instruction on installing the Keller sender in older oil pumps, its chapter 79 in SI-912-020R8 (link below).
Those are the only three sending units that have ever been supplied by Rotax for the 912 series engines. There are many other sending units available that will work and are popular options because they are priced lower and work without issue. We do sell them through our website and there are some links below.
Service Instruction SI-912-020R8
http://docusearch.flyrotax.com/files/pdf/d05601.pdf
Replacement VDO type oil pressure sending unit:
http://www.cps-parts.com/catalog/inpages/mglopvdo.php
Rotax supplied Keller sending unit and wire/connector assembly
http://www.cps-parts.com/catalog/rtxpages/oilpressuresensor.php
http://www.cps-parts.com/catalog/rtxpages/wireassembly.php
Alternative to Keller sending unit made by Falcon with 1/8"NPT thread
http://www.cps-parts.com/catalog/inpages/falconoilpressure.php
Any questions about this can be directed to Customer Service at California Power Systems, the West Coast Rotax Service Center.
www.cps-parts.com , info@cps-parts.com
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