Tachometer cable and drive for 250 Scrambler Head

[tonyduc]

Need some advice on tach cables. I have a 67 MK3 250 with a 250 Scrambler head (swapped by the PO). The tach drive on the engine is 12mm and takes a spade end cable. My tach is a Veglia with the square cable end. I have a cable with both square ends made for MK3 drive. Can anyone familiar with the DM 250 Scramblers tell me if there’s a tachometer cable that would work (having a spade end and a square cable end)? If no cable exists my alternative is to get a drive for a Mk3 (which were square cable type), but not sure if such drive will work with a Scrambler head ?

The best discussion on this is here but it doesn't answer all my questions
viewtopic.php?f=3&t=2186

Thanks!
Tony

[themoudie]

Aye Tony,

Could you post an image, please, of the type of tacho drive cover that you currently have? That would help others to advise.

I am only familiar with the smooth Smiths type of cover, as fitted to the MKIII and Desmo machines that used the small Smiths instruments:

1972 on Smooth tacho drive cover Smiths instruments

Personally, I don't envisage any problems with using the smooth cover on your 250 scrambler head, provided you check the length of the tang drive and bushing from the tacho drive cover to the end of the camshaft.

Might I suggest that a custom drive cable could be obtained from Venhill Engineering Ltd, if you are in the UK? A link to their website is below:

Venhill_Engineering_Ltd_website/contact_details

Good health, BillR

[tonyduc]

Hi
Please see attached. I was thinking also of modifying the cable as the least expensive option. At one square end I may try adding some weld then grinding to shape as a spade.