At what point do you end a startup relationship, if you're 1.5 months into development and the business cofounder says he only have 8-12 hours a week to work on a company? After saying he could do a lot more work per week other than responding to just emails?
Is there so much on the business end to complete while a SaaS web application is being developed that the business end should be doing from:
Are you working on it 40+ hours per week? It might be time to sit down and talk about where things currently stand. It really depends on what you've already agreed on (formally or informally). If you're working full time on it, and he's only working 10 hours/week, and he's a decent human being, he'd probably be OK working for a much smaller percent of the business's equity. A friendly non-threatening discussion about how you feel about the current situation goes a long way. For the record, yes, 8-12 hours could be enough time, in some situations. A lot of people get startups going in their evenings and weekends. It really depends.
IMHO, the problem here is not the amount of hours he's currently working, but rather, the amount of hours he's working compared to what he was expected to do, or compared to the amount of work you're putting in.