(Retrospective post for 14th November 2016)
However far more serious an issue was stopping, which "Flamingo" was really very bad at. Even thrown hard into reverse, with the engine running very fast, she would only "scrub off" speed very slowly.and the final stop seemed forever in coming. The very first lock we ever took her though I went in at what I thought was a ridiculously cautious low speed just in case. I soon found myself with the engine flat out, masses of black exhaust, but not a lot happening under the counter, and I thumped the cill quite hard, being able to lose all the speed in the length available.
Locks we could deal with - just tackle them even more cautiously, but where you met boats at blind bridge holes on bends things could be "interesting" to say the least. We certainly had our moments, though, fortunately, no serious collisions.
Also if you were trying to power round a bend, often the power to get the required steering was not adequate. You were then faced either with trying to wind on more power, knowing if it went wrong a collision with the side would be harder, or throwing it into reverse to abort the move. If you did the latter you lost most control, and often it would not stop in time then without at least some touching of the side. I learned much about what "Flamingo" would not do going round, (or not going around!), the well known ninety degree bends in Cassiobury Park - something I have had no trouble with in another ex "Grand Union" boat.
The propeller fitted proved to measure up as 25 1/4" diameter - that bit is fine. What didn't seem right was its "pitch" - basically a measure of how flat or angled the blades are to the boss. The propeller was not marked with size, by Brinklow estimated it as less than 17" pitch, whereas most indicators would suggest over 20" pitch was needed with this engine gearbox and boat.
Another of the well known names for narrow boat propeller work was contacted. They simply said that if the firm we had taken it to could not do it, they were not going to be able to either. So we had no modified prop, and enquiries about replacements initially talked of months of lead time for delivery.
Then Dave at Brinklow drew our attention to FAL Scottish Propeller Services in Banffshire. They might be able to supply us a replacement to arrive to go on before the boat had to come out of dock, and we started to go down that route, until Brinklow discovered the boat could not stay on dock as long as they thought. Unfortunately our options to sort it out in a single docking were now exhausted.
FAL reckoned the current pitch on the prop to be little more than 15", whereas general consensus was it needed to be at least 20" and probably as much as 22". In the end I decided that 15" to 22" was a massive change, and I wasn't quite brave enough that that would not overload the engine. We asked for 21" - still a fairly massive increase from 15".
I would strongly recommend FAL Scottish Propeller Services - not a name you might immediately associate with narrow boats, but very efficient - they did what they said, remarkably quickly, and at a reasonable cost.