We currently run a 9.8 Nissan/Tohatsu 2 stroke on a 12.5' SIB. On mildly choppy seas we hit 26 km/h (2 light people, probably 300 lbs, light load). Certainly a bit quicker on calm seas.
All is well with the boat and the motor - I love the weight of the Nissan. The boat has lifters, and with them planes with no effort. It all fits in my Nissan sedan.
It seems that SIBs are limited on top end speed because of their structure. Increasing HP to 15 doesn't seem worth it unless I had a planing problem. Increasing to 20 might... the question I have is what is the realistic increase I'd achieve with a larger engine? And would I notice, really? It seems people increase their HP to make their boats plane... the difference between 25 km/h and 35 km/h, experience wise, seems negligible.
As someone who hasn't gone past a 9.8 (but could take a 25, though need to pick it up, so wouldn't), I'm looking for opinions from people who have... do you "feel" the difference enough to justify the cost of a bigger engine?
All is well with the boat and the motor - I love the weight of the Nissan. The boat has lifters, and with them planes with no effort. It all fits in my Nissan sedan.
It seems that SIBs are limited on top end speed because of their structure. Increasing HP to 15 doesn't seem worth it unless I had a planing problem. Increasing to 20 might... the question I have is what is the realistic increase I'd achieve with a larger engine? And would I notice, really? It seems people increase their HP to make their boats plane... the difference between 25 km/h and 35 km/h, experience wise, seems negligible.
As someone who hasn't gone past a 9.8 (but could take a 25, though need to pick it up, so wouldn't), I'm looking for opinions from people who have... do you "feel" the difference enough to justify the cost of a bigger engine?