KR-1S.co.uk Forum

I rushed then end of the kr because this broke in june the big end has gone i think as it didnt feel right when i put new shells in it no taper rollers on this one and i just pushed it in the shed and left it

Anyway sat in the garage about 830 or whatever tonight and started pulling it to bits then thought its like a 2 stroke really. This is a late 1969 unit single 250 BSA B25 Starfire but even then we were still turning out pre unit engine designs but stuck in one casing. It not surprising the British bike industry went under. The cases split vertically so prone to leaks and the geabox has its own oil and is linked to the engine which is dry sump and its own entity via the clutch which just sits on the end and a primary chain.

Looks like any other modern engine from here apart from the gear change is on the right side and thats the oil tank not a panel just draining hence the pipes dangling about


Check out the other side once the casing is off though and the drive is exactly the same design as the 1949 BSA B31 pre unit i have. This side you have to put 1/2 a pint of oil in for the chain to run in so three seperate lots of oil.


Probably not the place for it but i just thought it might interst some of you.

I will just get me coat then i havent quite finished reading the phone book yet

That oil tank looks bigger than the petrol tank.....

It does look all flat cap, woodbines and tea though.

You can just imagine Arthur Fred and Percy working on it, "Eh lad just pass me the quarter Whitworth spanner, and then I'll be needing the nine sixteenths cycle spanner and the half AF and where's be bloody tea?"

I think I need to get out more.....

Excellant, I have a 1961 Triumph 5TA 500cc Speedtwin that used to be my Dads, its also a bit poorly and I decided yesterday to investagate why, I haven't yet though as I've not had the time but I will be doing.

The speed twins suffer from the same problem as these so they reckon the conrods are the weak link but i cant remember what you can fit instead.

It could be the late bsa rods actually i would have to look what you can swap with what.

Of course you could always just ride it normally and just cruise around

Nice bike though is it a bath tub model?