This is my 46 inch fireboat. it is a 1960s Aerokits model that I was given about 18 months ago only partly started (frames and stringers). it is powered by 2 x 770 watt brushless motors with 4s lips and has working monitors and an Action Noisy Thing sound system. it is pictured here at Tynemouth boating lake where I an a member to of the Tmbc.
I'll get some pictures when I next see it as it is kept at my Mums place in the NE where the lake at the Tynemouth club is big enough to take it given its speed and size. if you are blowing fuses, make sure you haven't over greased the shaft. I did that once and really only a light greasing of the inner shaft and some light oil on the bearings is all that is required. Also try a smaller prop. You may not get any reduction in Speer as the motor may rev faster and at lower amps. I've just taken the 50mm 3 blade brass props off mine and put 45mm 2 blade plastic racing props on and she runs faster and smoother. Hope this helps.
Many thanks for your comments, much food for thought. I look forward to seeing your photos when you've next been to your Mums.
Rgds
Dean