Hitchcocks Forum

Hello everyone.

I have a 2011 Electra EFI; I keep it garaged on an Opti-mate charger.

On occasion when cold-starting I get a 'clacking' noise while turning the engine before it fires up. Once started all is well.

Can anyone advise me what the noise might be and any remedies? I have tried kicking the engine over a few times before turning on the ignition but that doesn't seem to make any difference.

Thanks, Rich.

Probably the auto decompressor. Does the noise vanish when the revs build?

Second attempt the engine fires up and no repetition.

It's the auto decompressor as mentioned - have you changed the oil viscosity/brand? When I carried out a mid term (300 mile) gauze filter clean I put 10w40 oil in to top the level up and immediately had the infamous clacking noise on start up.

It disappeared 300 miles later when the oil was drained and replaced with 15w50. Not had it since.

Actually, I'm not sure what is behind ric's suggestion. The auto-decompressor is *supposed* to clack while it's operating. The clack comes because the cam follower hits a bloody great lump on the side of the camshaft.



If ric's engine really doesn't make the clack at all, even at cranking revs, then it suggests the decompressor is stuck.



Anyway, Rich, don't worry about it. The clack is definitely the auto-decompressor, and as long as it disappears when the engine fires and the revs rise above about 700rpm, it's all working fine.



I'm not recommending this, but I disabled that appalling engineering bodge within the first week of ownership.

When I had Thunderbolt, my EFI, he never did any clacking, and the auto decompressor worked fine!

No worries this end If I feel the need to experience some metal on metal clacking I can easily get some by reducing the tickover speed. The rest of the time mine's either silent or is being drowned out by the starter motor so I just think it is.

Thank you for all those replies.
Thank mentions that I can decommission the auto-decompressor. Can anyone tell me how to locate and undertake this?

Thanks, RIch

The little activating pin that operates the decompressor protrudes no more than 1/32 inch above the normal cam surface. Hardly a ‘great lump’ and not enough to create any great clacking that will be that noticeable above the racket of the starter itself and all the other mechanical noises of a cold EFi trundling into life.

Rich writes: " Thack mentions that I can decommission the auto-decompressor. Can anyone tell me how to locate and undertake this?"



It is actually very simple. Order a new gasket for the right hand engine cover before starting! I won't give step-by-step instructions, but to summarise:



0/ (Optional) Lower the bike onto its left footrest, so it rests at about 45 degrees (don't do this with the CGT!)

1/ Disconnect the brake actuating rod at the back wheel and let the brake lever drop as low as it will go.



2/ Loosen the right hand footrest so it will move and turn freely.



3/ Remove the right hand engine cover (fiddly, you will need to manoeuvre it past the footrest) and wedge/tie it up out of the way.



4/ Remove the alternator rotor (you might need a puller, but usually a rubber mallet is all it takes).



5/ Remove the plate covering the camshafts. WATCH FOR THE SHIMS. There may be none, one or two shims on the ends of the camshafts, and sometimes they stick to the inside surface of the plate. Just make sure you find them.



6/ Extract the entire decompressor mechanism from inside the exhaust camshaft. Don't let the camshaft ride up its shaft otherwise if it rotates you'll have to reset the cam timing.



7/ Put those shims back onto their correct camshafts.



8/ Replace the plate, then reassemble everything in the reverse order. You will probably need the new cover gasket because they are VERY easily damaged.



I want to emphasise an important point. The above is how to do it, but I do NOT advocate doing this. You do so at your own risk. I say that because without the decompressor the engine will be more prone to "bouncing back" off compression when you turn it off. Normally this is of no consequence, but some people claim that this bounce-back can damage the starter sprag. I've had three REs and none of them had a sprag failure, so I'm sceptical. However, others are convinced. RE fitted much stronger sprags in recent years, but I don't know if your 2011 has the stronger type.



Having said all the above, I think my advice would be just to live with it, unless it really bothers you.