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[jefrs]

Scotty - once I got the head to exhaust gasket sorted on the C5, it shut up almost completely.



Pretty sure we have bigger valves on the EFI and I do know the 535 has bigger, cleaner ports. We also have hydraulic lifters, which can be noisier at start up but which should shut up within say 10 pumps once the oil is flowing at pressure i.e. not long at all. Apparently we also have oil pumps on the latest EFI delivering about twice the flow rate of the pre-2011 motors. Any number of things were fixed or improved on the 2011/2012 onwards motors.



Do check your head to exhaust downpipe seal. I used two copper gaskets p/n 582638/A. The "cement biscuit" was as much use as a chocolate teapot. When I went in to replace with the copper gasket, there was nothing of the original cement biscuit to remove, it had disintegrated and been flushed out of the exhaust.

[jefrs]

Simon - the valve timing on the 2011-on motors is something RE have stuffed up their jumper. They do give timing in the workshop manual for the 2010 motors. They may be the same, or not... We do have 8.5 compression on the EFI, not incredibly exciting but you do notice it on the kick start and it does need that auto-decompressor. Does the iron barrel not have 6.5 compression?



If an EFI is "noisy as hell", it almost certainly the head to downpipe seal.

[scotty]

Not comenting on engine noise its noise at muffler, got somebody to ride bike down the road , efi exhaust bark muchlouder than similar setup on iron engine which is out to 535 accralite 8.5 piston so r is same on both bikes. Efi I find more engine noise than a properly set up iron with adjuastable cam spindles fitted getting rid of cam gear backlash which varies from engine to engine. Object is not to get nicked by the fuzz for a noisy bike but still sound good.

[jefrs]

Once more, my C5 EFI was very noisy on the exhaust bark, certainly enough to attract the rozzers, until I used the copper gaskets and got a good seal there. It was as noisy as hell, now it is not. I reckon it sounds pretty good, especially opened up a bit going up a hill, and I did find I could adjust the exhaust note by bending the baffles about on the 50s system (p/n 91130).



You can't really hear the gasket leak at the front, the sound comes out of the back.

[Chris Tindal]

Just put a straight through goldie silencer on the Bighead and it sounds awesome. Still quite different to the standard iron 500, which sounds almost like a Panther compared.