Harigo, what I mean by ( prime on the ground is ) when you get your engine running ( while on the ground ) turn on your smoke pump and make sure it is pumping smoke oil before you fly. If you don't do this the pump will not pick up a prime while the plane is in the air. Also set your radio up to about 70% or higher for the smoke pump anything less doesn't seem to work too well. ( At least it didn't with my pump.

I have not tried any home brews for smoke oil. All I have ever tried is the commercially available smoke oil. But I have heard that diesel fuel and automatic transmission fluid work well.

If I were you I would go ahead and try your Slimline pump. Yours just may work perfectly. I would hope that not all of the Slimline pumps are bad.

Good luck!