When I go to the track my car is so full of parts and pit items I cannot get another person in it and I do not have a small car. I have a race Savage that is built for racing and I use to use a pull starter but my pit man spent more time trying to start it then I did on the track so now I use a Roto Starter. Wish I could use a starter box on it. Never seen a pro racer using a pull starter as well as you have the drag of a one way bearing robbing a small amount of HP. If you have problems starting it a pull starter is only going to make it worse. But if that is what you want go for it.

It is not unusually to have to retune an engine during a day at the track. Any weather change can affect the tune on a glow plug fuel engine. One thing I do to all my engines before I ever run them is seal the engine. Possible you have a air leak?