Winter strip down

[mike the bike]

I started on the strip down I've been promising for years, primarily to cure the oil leak from the head and to fit the newer/better camshaft and get some parts powdercoated.
As it's progressing,  a few queries have emerged, which I hope the more knowledgeable forum members could shed some light on.

As I was removing the rocker cover, those 2 head nuts with the M6 female thread (that the rocker cover bolts attach to)  were fairly loose.  The one on the LH side was so loose that that special nut loosened off the head when I undid the rocker cover bolt.
As the leak is from the LH side, would that have caused the leak, rather than a warped head?
The other head securing nuts weren't over tight either.  I did torque everything up when I built the engine,  although I may have missed the aforementioned special nuts with the M6 threads

The other query is the spark plugs are very sooty.  Could it be because,  with the vibration,  the choke has a tendency to turn itself on during a ride or do I need to faff about with the air mixture screws and, if so, what direction?

The float heights,  clip positions,  jet sizes are all standard, as Soichiro intended.

[Bryanj]

Undertorqued or loose bolts will cause both an oil leak and a warped head. never had a choke vibrate to on if the locking pin was OK.

I would have the head and block checked for level, rebuild with accurate torque wrench and leave to sit for 24 hours with rocker cover off and check torque before finishing.

I have known both studs and nuts strip threads

[mike the bike]

There's no stripped threads, I think you misunderstood.  I was thinking of just torquing everything up again but as it's off the road for the winter, I may as well check for flat anyway.

What locking pin is that then?

[Bryanj]

Not misunderstood, just commenting i have seen stripped  ones, from memory isn't there a steel small diameter pin that sticks out of the carb body and locates in an indentation on the mechanism to stop it vibrating shut---It is a long time since i worked on a 400 so that may be a different model

[mike the bike]

I think it's just friction that keeps the choke open, I think I'll tighten it up a bit to stop it moving, although I suspect the air screws may need adjusting.   I'll do a search, there's probably something about it on here somewhere.

[Laverda Dave]

When I torqued the head down on my 400/4 I used a calibrated torque wrench. A couple of days later when I came to fit the rocker cover I thought I would check the head bolts one last time and found I could get another 1/4 turn on the torque wrench!  I put this down to the copper washers under the bolts having a bit of 'give' in them as I had annealed them before reusing.

[Laverda Dave]

The choke lever on no.1 carb has a very, very small ball held by a spring. The spring pushes the ball into an indent when the choke is off. The ball and spring get gummed up and stick in the carb but can be easily lost if the carb is deep cleaned.

[mike the bike]

I don't recall that but I'll take a closer look at it.  I'll let y ou know what I find.

[Chris400F]

The choke lever on no.1 carb has a very, very small ball held by a spring. The spring pushes the ball into an indent when the choke is off.

Are you sure? I have been looking at the Parts List diagram and the assembly on my bike and I can't see anything like this, and in operation there doesn't feel to be any sort of location of this sort.

[Nurse Julie]

The choke lever on no.1 carb has a very, very small ball held by a spring. The spring pushes the ball into an indent when the choke is off.

Are you sure? I have been looking at the Parts List diagram and the assembly on my bike and I can't see anything like this, and in operation there doesn't feel to be any sort of location of this sort.

Nope, my choke doesn't have any of those parts either

[Nurse Julie]

I stand corrected, well sort of. Yes, definitely a click but cannot see spring or ball bearing. He that knows all has just shown me on another set of carbs that are off of a bike where the spring and ball bearing is located. No wonder I couldn't see them !!!

[Chris400F]

I stand corrected, well sort of. Yes, definitely a click but cannot see spring or ball bearing. He that knows all has just shown me on another set of carbs that are off of a bike where the spring and ball bearing is located. No wonder I couldn't see them !!!

Which bit should I be looking at Julie?
I still can't see a spring or a ball bearing, and I had looked at exploded diagrams and the CMSNL part before the earlier post.
Can't see anything that looks the part in the picture of the Link Set (CMSNL part 91).

[Nurse Julie]

I stand corrected, well sort of. Yes, definitely a click but cannot see spring or ball bearing. He that knows all has just shown me on another set of carbs that are off of a bike where the spring and ball bearing is located. No wonder I couldn't see them !!!

Which bit should I be looking at Julie?
I still can't see a spring or a ball bearing, and I had looked at exploded diagrams and the CMSNL part before the earlier post.
Can't see anything that looks the part in the picture of the Link Set (CMSNL part 91).

It's the bit you can't see Chris  Under part 91 on CMSNL it shows the spring and ball bearing. It's on the inner side of carb No 1, on the carb body

[Chris400F]

It's the bit you can't see Chris ....

Well that explains it then!
Actually I can see it now; it is clearer on the diagram on P35 in the 350/400F Shop Manual.
I also hadn't realised that part 91 on the CMSNL diagram is shown in two parts - I need to look more closely! Thanks Julie.

[Nurse Julie]

We both learnt something there then Chris. So if we ever loose out 'click' at least we know where to start looking now