I’m having a weird issue with my 750.
It has 2 keihans, and the nuts that hold the headers to the engine keep coming loose.doesnt matter how tight I make them. The parts diagram says there are 2 special washers to be fitted. Now I do have 2 washers, but I don’t know if they’re original. Is there something unusual about these washers?Â
Am I missing something?Â
maybe they should be some type of spring washers,
Yes try spring washers, this does ring a bell with me. Pretty sure I’ve got spring washers on mine ~ the type with a split.
I remember the chrome-plated brass flanges on my Targa were prone to mis-shaping under tightening of these nuts, which did not help wit the header-cylinder head seal.
I even had to drill out the holes to 8mm to clear the puny 6mm studs because they were so bent! I don’t think I was ever really satisfied with the tightness.
The nuts, I recall, were about twice as long as a normal M6 nut but I don’t remember there being any specific spring washer originally even though I may have fitted one in deparation.
Jon
Just checked my 750 targa and it does have washers. They are not special accept that they are “internal tooth” washers. These are very thin but have teeth protruding providing grip. You may get away with a standard spring washer but to my mind, there is a reason why Guzzi used the toothed variety and suspect that’s the source of your problem. They are easy to source and suggest you try Gutsibits who are bound to have them.
Hope that helps
Aka, “shakeproof washers” 
Brilliant, thanks guys I’ll get straight to it,
Fergal.Â