Hi Roy! This boat came with a 25cc lawn mower engine fitted, any idea what I can replace it with? I'm looking at electric.

Hi Roy!
Thank you very much for your advice, itis very much needed a set of plans would be very useful, any ideas where I can get some😉. This model was built about forty od years ago, she is six foot long, and although might be from plans she has been heavily modified, and scratch built with whatever was in his shed.
I hope to be putting some more pictures on here soon (when I can get my camera working) but I do need advice on how to repair the hull. I have to replace and fibre glass the stern as it has rotted away. I can do the woodwork but have never done fibre glass repairs like this before, any tips will be gratefully accepted.

Hi you seem to have been by-passed by other posts. I think I have the plans of Barbara in my pile of plans. I note the identification V25 which suggests she was a Straight runner in her day.

If I reacall then she is about 4 feet long and you need to decide how fast you want her to go.

I suggest just about planing would be good, a nice little bow wave. I completed another a boat about this size a few years ago but I think of lighter displacement.
If you are using brushed motors then you need to have about 2500 rpm at the prop which should be about 45 - 50mm dia.

The motor will better run on 12 volts and maybe a unit with a built in gear reduction of 2.5 : 1. I think an MFA one will suit or a 12 volt Hectoperm (with gearbox).

With 12 volts rather than 7.2 volts the electrical losses are less and the motor brushes are cooler. Power consumption 35 -40 Watts. i.e. 12 volts at 3.5 amps on full power.

A large Nimh pack 4600mAh will suit. Rather expensive I know. Do not bother with lead acid they seem cheaper but they are not when it comes to stored power.
I cannot advise on brushless or LiPo but for a period boat I would advocate a period power unit.

Hope this helps.

Regards

Roy