The sticky throttle plate at high temp is a common problem on the early 113.042 .. These had standard advance , where the later [ and all other 113s ] had vac retard. This should ,as SB said, be checked as it may not be coming back to idle timing. An easy way to check is w/strobe light , but you can also disconnect the vac hose and listen for rpm change.
I can tell you exact specs if you list the dist #.
Here is more info on the basics of these Mechanical Injection systems..
It is also advisable to check the dip stick at the rear of your pump for oil level.. the early pump had an oil res that must be owner checked/filled . These never get checked and will effect operation.

http://www.sl113.org/forums/topic.asp?TOPIC_ID=2257&SearchTerms=air,bleed,rich

This refered to site postings have to be read from the bottom to top for sequence for some reason, so start at end..