hello a couple of questions to older members,, i have just bought two 1974 247 engines and one is fitted with a reed valve, it is well made and made to use a amal carb, i have looked online and found reed valve conversions , but these apear  as a later mod and use a mikuni carb. has anyone seen one of these or know anything about them.. the second question was do they work??. i have to strip and rebuild the engine is it worth leaving on, i will be using a new amal carb,, thanks for any help,, 

It could well be a Keith Horsman conversion as he was a Montesa dealer in the 70s, rode a 247 and developed a reed valve for them (Harpower) although I don't know which carb he would have uised on the Mont.

 

He subsequently fitted them to Ossas and Bultacos. He did an Ossa for me many years ago and it gave an increase in torque and let them rev a bit more, so yes they're a worthwhile improvement.

 

A clever man was Keith, self taught engineer who sadly died a few years ago now. I enjoyed a few trips to his home when he was doing work on my Ossas for me - always had a tale to tell

thanks for the reply,, i have took the reed valve of and cleaned it,, the reeds have no cracks and are air tight ,well they let in no light,, so i will leave it on and give it a try,, thanks again