Conductor Culprit
While it appears the solonoid might be a problem the suggestion that wire size is too small raises a red flag. We bought our H-35 new in '88 and had somewhat of a starting problem since new. Part of the problem was the group 24 batteries which had been run absolutely dead on several occassions, both by the dealer and then a couple times my myself - a potential problem in itself. When the batteries were upgraded to golf carts the conductors were upgraded to double 0 with #2 to the starter and engine ground. Even with all the new batteries and larger conductors the engine starting improvement was only marginal. The engine ground was the last conductor to be upgraded and it made a major improvement in starting. Never did find the reason why: larger conductor, bad connector on original cable, bad contact, ?, but my suspicions are that it was either a connector or the contact. The original wiring installed by Hunter was not tin plated, i.e., not marine grade, which could lead to corrosion or oxidation of the copper. It was about five years later that it was removed.Low voltage on the starter motor will wear it out prematurely so upgrading the conductors wouldn't hurt even if it is a solenoid problem, and who knows, the problem might resolve itself.