Hi,

with some technical skills, You can fix the starter clutch by opening it carefully and replacing the tiny rollers inside. These rollers are very likely to be no longer round. That's what makes the clutch run free. You should get such rollers in any shop, selling parts for roller bearings. In Germany, these parts are less than 5 cent, each.
Just give it a try. You got not much to lose.
You can also block the clutch brutally by welding or by forcing some screws in the case. As the clutch is not really needed in this engine (no joke!) some people just kill it that way. Personally, I prefer mending the thing as described.

good luck,

Stefan

Hi, just to let you know that if you haven't got a new starter clutch yet, I got a heavy duty one from SORGY's in America for $110 including shipping as the standard one in the UK is £249.00 so you can tell wich one I bought.

Yours The Reaper