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[Al Crusader]

Hi folks, probably being lock-down induced sensitive, but my recently acquired 500 EFI (B5) sounds a bit like a diesel Enfield ticking over. Would that be the hydraulic tappet set-up? Only noticed it yesterday and can't say if I remember it before. Only had the bike 3 weeks before this lock-down can't go out thing, and have only changed the oil and filter and done some local miles. New experience with the EFI. My other two Enfields are both much older.
Bad noise or normal? Cheers.

[Haggis]

Certainly should not be sounding like a diesel.
The hydraulic lifters take care of themselves. Assuming you put the correct amount of 15/50 semi or full synthetic motorcycle suitable oil in?
Is your tick over speed maybe a little low?
Loads of videos on YouTube will give you an idea of what one should sound like.

[Al Crusader]

Thanks Haggis. will go to you tube.

[PeteF]

There is an auto decompressor I think?
If your tickover is too low it could be this?

[Al Crusader]

I will check that out as well. I have the Haynes manual.
And Haggis, When topping up to the correct level after oil change, I managed to put in too much oil. Only half a tea cup or 30 cc or so. It took a while to register in the level window and after running the engine and letting rest, the inspection window was full. I am imagining it was after this that the mysterious thumping started. But as I said, not being familiar with this bike and not even ridden it because of current craziness, I can't be sure.

[Daiwiskers]

I use a measuring jug for oil changes now, kitchen type cheap and easily available
Check the book for quantity wet or dry then add that amount it seems fussy but it takes the guesswork out
Also handy for fork oil etc

Take care all Dai

[Haggis]

A small amount like your 30cc of oil would not cause any problems. Does the noise go away or stay the same if you rev it up a little? Just to make sure it's not the auto decompessor which activates at very low revs.

[Al Crusader]

Haggis, the noise stays, speeds up and gets a bit lost in the increased other detonation/exhaust and general engine buzz. Where and what does the auto decompressor do?

[Haggis]

It has two functions, one is to release a small amount of compression when using the electric starter giving it an easier life.
The other is to prevent kickback, when you switch of the ignition the piston can sometimes not go over top dead centre and kickback in reverse direction.
This is very bad for the one way sprag clutch that the starter motor uses to turn the engine.

It works by opening the exhaust valve a small amount to reduce the compression pressure.
It only operates at very low revs, like under 1000 rpm or thereabouts.

https://youtu.be/wU-QbPUCFxg

[Al Crusader]

Thanks, I will monitor the situation and report later.