(make sure you pull the exhaust collars and re anti-seize them every year don't ask why I say this). I have found a set of heads from a '79 that will get me through this summer - will they work? I
Roy
To which I would also add - remove the pipes every year or so also. When I decided to do some very overdue maintenance on the wife's bike I bought a pair of US model heads and had new valves fitted to them, the thinking was to use them while doing up the existing heads and thus leaving us with a spare set of serviceable R80/100 heads.
Sadly I could not remove the headers after cutting the nuts off. I tried everything and so did my trusted machine shop. eventually, with great sadness I issued instructions to preserve the Staintune headers as they would cost $AU600 to replace and destroy the heads to remove them.
As regards putting the 79 heads on a post 81 engine. Yes they will work, but the jetting is likely to be a long way out - there is a solid 5hp difference between the 79 and 81 edition, still if it is for a short period only, you are unlikely to care much. You do know that there are other repair methods available these days aside from repairing galled threads? Some are ugly, some are pretty good looking. Still it isn't a complicated job, most good machine shops will already have a right-angled work piece able to be bolted to a lathe faceplate. send the head out to have the damaged thread built up with weld, bolt head to faceplate, use mandrel in exhaust port to center and then turn the thread area to size and then cut threads. The hardest part of the job is centering the work, after that it is all simple machining.
