an url with https is a different url than one with http, therefore the seo from one url does not carry over to the other url after the change. it is more like starting over with new urls.
inbound links and other things that affected the old url seo do not affect the new url.
so if all the urls on your site changed it may take a little while for the seo to come back as it was, you should not expect it to happen immediately.
however in the long term it is better to use ssl on all urls. google has even said that they will favor secure urls over insecure urls but that you should not expect to see any dramatic page rank improvement.
as always the main thing for seo is high quality content.
my advice is to be patient and your seo should come back as google indexes your site and sees the new urls, and use google analytics to make sure your traffic is still being captured correctly after the change to https.
the mojoportal sitemap.ashx should reflect the new https urls and the cannonical url links in the head of each page should also reflect the new https url. as a result google should see this change and the new urls should over time be back to the same seo as the old urls.