Thank you for reporting back so promptly and accurately, Barro. I'm glad the problem was one that is somewhat usual and fairly easily fixed. From what I have seen that engine is capable of giving good and reliable service, as well as being particularly easy to start and operate, while being unusually smooth-running and pleasing.
There are a couple of characteristic weaknesses, in particular a risk of the camshaft drive belt jumping a tooth or two, or if you neglect to keep the cylinder head cooling fins free of dirt or grass, overheating and subsequent valve gear problems. However even if these things occur they are usually very easily fixed. Please let us know if at any time the engine ceases to run well - we'll be glad to help.
I'll close this thread.
