Primer lines need to be silver soldered into their fittings. Using RTV to fix a leak is not acceptable and poses a serious fire hazard.
In Case You Missed It
Minimax to the Rescue
It's not easy to find a tug/tow bar assembly substantial enough to handle the job adequately and still be portable enough to be carried aboard.
The Final Steps
What you need to get your airplane’s experimental airworthiness certificate.