[NickHonda400Four]

Hi Gang!

Hope all is well throughout the RE community.

The time is approaching for me to get ordering consumables for my C5 to complete a winter service. All the usual stuff, spark plug, brake pads, oil and filters, electrical stuff etc.

The bike has developed a very mild knock at low revs under load/acceleration. It’s in the realms of the ‘lugging’ rpm which I don’t make a habit of entering…but it’s a knock that wasn’t there during the summer.

There is also a bit of rattling rocker or cam backlash noise. So I’m going to a a full inspect of both the rockers, hydraulic lifters, cam backlash and do an inspection on the piston.

While I’m at this, I’m wondering if a few upgrades could be worthwhile. I’m already on a Mikuni carb along with Hitchcocks very lovely big bore curved header pipe and bottle silencer.

I’ve been offered a 525cc conversion barrel and piston for a reasonable price.

Hitchcocks are hoping to have their performance cams back in stock over the next few months.

There are also those performance valves and springs.

Anyone have any experience or recommendations with the above?

Thanks all!

[Antipodean Andrew]

I noticed my C5 had a rattle at lower revs when the air temperature was close to freezing. After the engine warmed up the rattle went away. Being in the Southern Hemisphere temperatures are getting warmer, so no more rattling.

[fressko]

I had that knock pretty much from day 1. When accelerating from lowish rpm under load sounds like rod knock, which i very much doubt it is. It comes only when accelerating under (some) load and no it is not lugging. You know what I am gonna do about it?... Absolutely nothing, I am just gonna ride it until the wheels fall of. If you do find a solution on yours, please do share though!

[Richard230]

I had that knock pretty much from day 1. When accelerating from lowish rpm under load sounds like rod knock, which i very much doubt it is. It comes only when accelerating under (some) load and no it is not lugging. You know what I am gonna do about it?... Absolutely nothing, I am just gonna ride it until the wheels fall of. If you do find a solution on yours, please do share though!

You could give premium fuel a try. Perhaps its higher octane will cut or reduce the knock under load.