Thanks for posting those Hutch, I hadn't seen them before and was guessing at what they looked like.

I will get them Laser cut and the radius that is on the eye I can do carefully on the linisher and where is winds into the spring I can do with a small round file.

I'll post some photos when they are finished.

Regarding the thread for the shoulder bolts, according to the list of threads they are;

Forks spring anchors on later forks. Qty 2 fork end.                                    3/8” x 20 tpi. BSF.
Fork spring anchors outer end and special pivot nuts. Qty 4                        3/8” x 28 tpi.

The parts are in my workshop on the other side of Auckland so I will need to double check to make sure


Cheers

Marcus

Dear Forum
Could someone please assist, on disassembly of the drive sprocket on my Mk 4, I notice the the stop collar for cam was missing part # 32426 according to the parts manual. Would anyone know the width and diameter of the stop collar and is it made from steel or alloy. Looks to me, to be a spacer between the shock absorber driving cam and collar for the spring.
Thanks for any assistance
Darryl

Hi Marcus,

I have a few  used rough TS / CW springs with the ends removed so I have been able to measure these dimensions for you;

"Free Length = 6 inches"

Note some of these springs have been slightly stretched at the ends where the screw in fitting goes. No idea what the spring length was originally as all these springs have been used.

Spring 1   5.84"
Spring 2   5.77"
Spring 3   5.78"
Spring 4   5.73"
Spring 5   5.81"
Spring 6   5.78"


"Outside diameter = 1 1/2 inches"

Spring 1   1.37"
Spring 2   1.39" some surface rust
Spring 3   1.39" some surface rust
Spring 4   1.37"
Spring 5   1.37"
Spring 6   1.37"

So diameter is probably 1 3/8"

"Number of coils = 18"

Yes all 6 have 18 full turns

"Wire gauge = unknown"

Spring 1   0.212"
Spring 2   0.218"
Spring 3   0.218"
Spring 4   0.208"
Spring 5   0.208"
Spring 6   0.212"

So possibly SWG (British) 5 or approx.7/32" diameter wire ?



A pair of these used springs are possibly surplus to my requirements but would probably take a bit of work to clean up and polish adequately for nickel plating if that was the finish you were going to use. They would be ok for painting tho'. PM me if you are interested.

I have some new springs which came with a job lot - origin unknown, length 5.74", diameter 1.38", wire diameter 0.209" 19 turns rather than 18 - so they will be slightly softer than used original springs shown above.

"And a sketch with dimensions of the ends that screw into the ends of spring please."


The ends appear to be cast  (i would assume them to be more uniform in appearance if they were forged?)- I would guess the original material is steel rather than iron but not 100% sure as I have had one shatter when I unscrewed it out of the spring (this procedure can be interesting as the spring grips the fitting quite tightly and it is hard to get a good hold on the spring! If I had to do it again I might make a jig to make the job easier). I don't have enough spares of these for a full set of the ends but PM me as I have a spare rough one you could use as a pattern or I can sketch it for you.

It would be interesting to see what dimensions other forum members have for their vintage 2 3/4hp fork springs?

Cheers

Hutch

Yes, that looks loose, not so much as to not be operable, but  you are going to have to compensate for it with the air slide.  It will also cause erratic operation as was mentioned by Graeme.

Hi Phil,

thanks for your photo to give me help.
But unfortunatly it do not help, because it is a MK engine.

My problem are 2 different idler gears I have (difference in length of axle). The longer one is a standard MK one, the short one is unknown.

I think the front crankcase (Plus to MK) has a small difference in the timing chest, f. ex. you can not extract the cam pinions and get them out without splitting the crankcase halves.

At the moment I can do no test, because the engine is assembled.

Michael


Michael

That is the reason I would like to know, if there is a special idler for the Plus models.