April 2021
1975 Kawasaki H1F MachIII 500
The Kwaka came back.
Once again it had sat for long enough that the carbs had gummed up with old fuel and much flooding was happening.
At least I had been here before and could remember the necessary sequence of events.
As can be seen, the carbs sit above a valley in the crankcases, which unfortunately does not drain anywhere, so pools of fuel sitting in there make one feel a tad insecure.
Despite cleaning all the jets and taking care with the float needle, the carbs would still overfill, one at a time in odd intervals. The only treatment that made sense was to lower the float levels slightly, which had the required effect.
The float needles in these carbs have a shaped needle with no other measures to seal the fuel flow than to have a neat fit between taper and jet. Over time the tapers have worn to the point that they will not always seal.
A further strip involved using a fine emery paper to try and smooth the surfaces of the tapered ends to effect a more perfect match, but it seems that replacement float needles are now needed.
Not sure where to find these parts, but the bike is usable until they are located.