Part 21 Inlet and Exhaust Valve Disassembly and Cleaning ...

Introduction ...

This page contains photos of the process of inlet and exhaust valve disassembly and cleaning from a ROTAX 912ULS engine (built August 2006).



ROTAX 912ULS Inlet and Exhaust Valve

Image 1

Here we start with a cylinder head that we have already removed the pushrod tubes from. To release the valves we use the specialist valve spring release tool to compress the valve springs so that the collets can be removed. Once the collets have been removed the valve spring compression can be released and the valves and valve's can be removed from the cylinder head ...

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ROTAX 912ULS Inlet and Exhaust Valve

Image 2

Here are a few different views of the valve spring release tool screwed into the cylinder head. This tool makes it easty to remove the collets but there are plenty of generic valve spring release tools that will do just as good a job. Always store the collets with the valve they came from so that bedded in parts get stored together and thus re-fitted together ...

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ROTAX 912ULS Inlet and Exhaust Valve

Image 7

Here is the inlet valve pre-cleaning ...

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ROTAX 912ULS Inlet and Exhaust Valve

Image 13

And here it is once it has been cleaned of debris in the ultrasonic cleaner ...

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ROTAX 912ULS Inlet and Exhaust Valve

Image 14

Clearly it is important that both the valve face and valve stem are cleaned thouroughly.

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ROTAX 912ULS Inlet and Exhaust Valve

Image 15

The valve seat will require lapping in again before re-fitting to the cylinder head ...

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ROTAX 912ULS Inlet and Exhaust Valve

Image 16

The inlet valve cleaned up and on the bench ...

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ROTAX 912ULS Inlet and Exhaust Valve

Image 17

And here is the exhaust valve pre-cleaning ...

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