I thank you all for you comments.
I know a hot 4 cycle plug might cure my little problem, but I do need to add some more nose weight to my pusher jet. I do not like adding weight unless I can use it for something extra than just the weight. Since I have the little dead stick problem at times I thought I might try a on-board glow[:@].
I did built this simple C cell on-board system and I can say it works better than I was hoping for. My ST-90K idles at 2000RPM and I am hitting 12000RPM with MAS 12x6 3 blade prop. I know the glow is on threw the hole flight. I ran 3 tanks of fuel today on the engine with no dead sticks and the best idle this engine has ever had. The total cost of the simple on-board glow was $6.28. I am looking into getting a C cell nimh so I can recharge the battery. It looks like I can get 8 to 10 flights with a C cell akaline battery.
This was a checp and simple fix. If I used a hot 4 cycle plug it would cost about the same