Engine Rattle at LHS - video

[c7ll]

I HAVE FIXED IT!!!

This engine rattle is actually the starter clutch. Here's a step by step guide on how to fix it:

1) Remove fairings and drain oil
2) Remove left hand engine casing as you sit on the bike (small kidney shaped one), If you're careful when separating the casing from the engine you may save the gasket, if not a tube of loctite silicone blue has always provided a good seal for me
3) As you look at the gear arrangement, the left hand side as you look at it has a 14mm bolt with an odd looking cog sitting underneath the bolt; this is the area you need to work on.
4) Undo the 14mm bolt, it's probably fekin tight so here's a few options on undoing it (assuming you don't have an air gun available)
a) Put bike in 1st gear and sit on the bike with the rear brake jammed on tight
b) remove right hand engine casing and hold rotor bolt (steel dish to the right) , also 14mm and the same torque setting (If you go this route then make sure that when reinstalling both the stator and starter clutch bolts are done up tight as one can undo the other. Both should be at 85nm from memory but do check)
5) Slide off weird cog (actually the timing gear, it's a splined shaft so can only go back on in one position)
6) Remove starter clutch. The following link shows a diagram of the starter clutch arrangement:

http://www.cmsnl.com/honda-cbr400rrk-nc ... t/E07.html

you will see that the guts of the starter clutch are riveted together and as a result the clutch itself cannot be dismantled, however if you remove the spur gear and roller bearing from the back of the starter clutch and then push the clutch housing from the inside hub you will probably see the rivets protrude slightly when viewing the clutch from the front (mine had no more that 1.5mm of play and the noise from the engine on tick over was very loud) it is this slack causing the knocking/ ticking noise. 2 options on how to fix it:

a) Ring Graeme France and get a replacement 07778 628448. £30 delivered to your door
b) Take your rattling starter clutch to a welder. Push the inner hub so you can see the slack in the rivets and then spot weld the head of all 3 rivets. Ground off excess metal so it's nice and level. (I went this route; it cost me nothing and so far has done the trick.) Check for play once it's cooled down.

7) Re-install starter clutch making sure all gears line up and slide on timing gear (it will only go on in 1 position), do up 14 mm bolt to specified torque

8) Replace engine casing making sure dowels are in place. If the old gasket is in 1 piece then run a smear of silicone blue (available from Halfords) along the gasket before installing and then leave to dry for 12 hours, Otherwise Graeme France will supply a new one in which case no sealant required.

9) Fill the bike up with clean oil (do the filter whilst you're at it) - DON'T FORGET THE SUMP PLUG FIRST! (I've seen a mate poor 5 litres of £40 oil on the floor via the engine's filler cap! - tit.)

10) Fire it up and marvel at the genius that is Honda's NC23 engine, without rattle!

11) Replace fairing - GO PLAY!

Any queries then do let me know.

Cheers,

Chris.

[Wozza]

c7 - you're a legend! Will get mine sorted sometime.

[ibby4585]

well done matey, ive got an NC30 making siimilar noises, did yours do it while you were riding it, or did it do it stationary? if so do you reckon it could be the same thing for mine?

Thanks
Kris

[c7ll]

I haven't ridden the bike yet so can only speak for standstill. Wozza might have more info on when moving.

Cheers,

C

[Wozza]

At the time I thought I could just about hear it while riding, but it was mostly drowned out by the (normal) engine noise. So I could've been imagining it, but it is definitely most prominant at tickover.

[GF Racing]

And who gave you the advice on what may be wrong ...

Graeme

[c7ll]

You did graeme. Thanks for your advice. Do let me know if any of the above instructions seem incorrect.

Did you receive my email?

[GF Racing]

Just been passed to me ... by my son..

[floyd]

ive just stared to do mine,and haveing no joy undoing the 14mm bolt.
A.wasnt working bike just kept moveing so i went for b.
B.removed other side of engine and held the 14m nut there and that nut undone instead of the starter clutch bolt?
ANY IDEAS GUYS????

[amorti]

Has anyone said "starter clutch" yet?

The one-way bearing will eventually either explode, or stop locking on and you'll have to push start the bike.

edit: read the thread and yes they had.

Here are pictures of how a German CB-1 owner sorted this... don't worry about the German, it's same description as above, but with pictures.