Tapping / Clicking Noise from Engine A Series 948 cc

[paulllllll]

Hi All

If anyone can shed anything to help, it would be much appreciated. I am not so much a Moggy enthusiast as someone who bought a boat a few years ago powered by an A Series 948 cc engine....so my appreciation for these classics came about in a roundabout way.

Anyway, after not starting the engine for 4-5 months, she fired up very easily a few weeks ago (after the magic spray in the carby!) but I immediately heard what I would describe as a tapping, clicking noise. And same thing today. It is not an excruciating noise, not a bang or a grind, but I am sure it is a recent development and it concerns me. The boat has forward, neutral, and reverse and this noise is when I start in neutral. And it increases in frequency and volume when I rev the engine. Sticking my head in the engine bay it sounds as if it is coming from the bottom of the engine, on the side where the carby is. I cannot find anything lose that is rattling, it sounds as if it is coming from the inside of the engine, at the bottom...the engine has always plodded along and has given me no trouble...I simply never go too far or fast, though admittedly she has been stationary for the last few years due to a baby!

Some more context - last year lots of water got in the fuel tank and she obviously wouldn't start: I drained the fuel tank, all the fuel lines, changed the fuel pump with a spare I had, cleaned the carby, replaced the spark plugs, oil filter and oil....and eventually got her going again...and there was no such noise....but after not starting her since then, it has suddenly started. This work is the extent of my mechanically ability, buying the boat and the engine has been a learning process for me....fortunately with help from forums like this, I have managed to get by.....but as mentioned, a noise inside the engine is way out of my depth. Any hints, tips, thoughts, on this issue would be great. At present, I am very reluctant to run her for too long as I don't want to damage her so any attempts at diagnosis would be greatly appreciated.

The oil level is fine, saw today the transmission level is just above low but not sure if that is the cause as I am in neutral with the noise....I have attached a few pics, I also have a good video from my phone that picks up the sound but cannot upload it. More than happy to email to anyone who thinks they can help.

Thanks again
Paul

[philthehill]

Whilst I have not heard the noise I will make some educated guesses as to what it could be.
When was the timing chain last examined?
When the rubber timing chain tensioners wear the timing chain can slap against the timing chain cover and make the noise you describe.
The cam followers are on the carb side and are about halfway down the engine.
The cam followers do eventually wear out the cam follower again can make the noise you describe.
Is the exhaust manifold leaking as a result of the manifold gasket failing.
Look at the above and eliminate if possible.
If still no joy come back on here for further help.
Phil