Originally Posted by Goinfishin
Any thoughts from the more experienced would be appreciated.
Same happened to me on the Thames yesterday. Yamaha 8 hp 2 stroke on a SIB. Lost the tell-tale with 4 miles to go. Took cowling off and monitored temperature, but kept going as it seemed to run well and cool.
Turned out the tell-tale was blocked. Cleared it with a 2mm drill by hand. The engine kept cooling - most of the circulated water exits from the centre of the prop.
Having said all that, the manual says STOP if no tell-tale!