i'm trying - at a distance - to help a friend get his old 66 Tiumph 650 going again. It has a single roundslide Mikuni VM 34(?) on it . He can get it to run for 5 or so seconds with a shot of starter fluid. He has had sludge / dirt issues and we are thinking the carb is still dirty.
we believe his pilot jet is a #25. If everything I read online is correct then Mikuni # s refer to flow and to convert this to mm I must divide by 200. This gives me an ID of 0.125mm which is tiny.
By contrast the pilot in my Keihins are a 35 which means the ID is 0.35mm and a high E guitar string at .28 mm is pefect for clearing crud but would be way to big for the Mikuni. So what would be good to use on the smaller Mikuni?
Trying to do some homework in advance of seeing the bike which may not be for another week or 2
I know this not a kz issue but also that many of you have Mikuni carbs and perhaps someone may have encountered this in the past.
Alternatively we may be better just identifying for sure what jet is in there and just buying replacement.
I suggest soaking the jets in carb and choke cleaner spray with a top on it over night. A single carb for two cylinders should have a larger pilot jet. Could be the varnish makes it seem smaller. The wire brush strand is smaller than an E string but isn't very strong.