Blocks and carbs
They say the 1998 and 1999 40 hp and 60 hp blocks and carbs were different,
To-days replacement parts show the same parts for both.
The carb main jet can be 44, 52 or 60.
Modified 59 cubic inch motors.
The first one I know of is Jeff Dunn's in 2014.
It was able to turn a 12 x 23 at 7000 on a T type V hull.....73 mph
Since then Jeff has built a few for the tiller drag class.
https://www.youtube.com/watch?v=S0DubylQUugHere is what he found out.
- the larger carb on the 52 cubic inch and the 59 cubic inch 60 hp are good enough for a mod 59
- the porting can be different in blocks , but you can port any of them similar
- the 1998 60 hp block appears to have better STOCK porting.
Hydro Tec has also played with the 59 cubic inch Mercury.
If you want to spend lots of money it is possible to get over 90 hp out of the 59 Mercury.
They have close to 200 compression and run on race fuel.
Problem is they cost more and perform less than a mod 90 yamaha
THE GOOD NEWS IS.....IT IS EASY TO GET 80 hp AT THE PROP.
It runs on pump gas!
You need an early year 60 hp block.
Clean up and match port it to the legal APBA spec.
Install Jeff Dunn 160 compression pistons...LEGAL IN T CLASS
Likely need 60 main jets
Install plastic reeds
Maybe shorten the tuner.
THEY LAST same as a stock one.
