Adjusting Coolant Inlet Elbow

Hello John

The inlet nipple is the same as the water pump casting.  The process is also the same to remove them and install them.  Be sure to use the correct Locitite.  the process is found in the Heavy Maintenance Manual

Cheers 

Thanks for that.  Same part number, different Loctite, different temp needed.  Didn't see that page in my searching.

I prefer Loctite 648 because I never worry that it may leak or loosen if someone bumps it too hard. I have had Loctite 243 / 242 leak from the factory.

Quote:

The difference between Loctite 242 and Loctite 243 is that Loctite 243 is a slightly upgraded version of Loctite 242. You’re unlikely to notice the difference, but 243 actually has a slightly better oil tolerance than Loctite 242.

I have to adjust the #4 cylinder coolant elbow. Can this be done with the cylinder head attached?  The site video shows adjustment of an elbow on the water pump off the motor but doesn't mention what to do with the cylinder head, neither does the maintenance manual. I guess the head can stand more heat than the pump.

The Loctite data sheet says that at 120 ºC, the bond is still 90% of the room temperature strength and disassembly temperature for a fastener is 250 ºC.

Given that Rotax designed the engine mount directly in line with the coolant outlet on #4, you might hope that they'd not fasten that elbow!

Hello John

You can adjust it while attached.  The main thing is not to damage it removing it and not to heat up the other bits.  The Loctite the factory uses now is changed (the old thread is from 3 years ago) now it is Loctite 577.  This is a more suitable thread sealer but you must install it cold and allow at least 10 hours to set.  

To remove the old nipple I always use a small piece of wood dowel.  Dress the end so it will go into the nipple at least 25mm/ 1 inch.  It is important that it fit snug without a bunch of clearance.  About a full hand width sticking out to act as a handle.  Warm up the nipple as suggested and then using the dowel as a handle slowly turn out the nipple.  Clean the threads on the nipple with a brass brush and the threads in the head with the required 18X1 MM bottoming tap.  Avoid regular taps as the thread has to be as square as possible for the tap to clean all the way to the bottom.  Rotax sells one in the tool list but you can also buy a bottoming tap, just do a search for the 18X1MM. This is the same thread and method of removal and install for all the coolant nipples.  

Cheers