Starting glow plug engines in the inverted position has always been a problem. That is why I replaced my OSMAX BGX with a Brison 2.4. They are pretty close to a direct replacement although some modifications were necessary. The engine starts in the inverted position with no problem at all. As I remember, the BGX was really a guzzler and I paid for the Brison in less than a year with the savings in fuel costs. Bite the bullet and make the switch. Once you do, you'll regret that you didn't do it sooner. Dan.