6/8/9.9 differences

[bbstacker1]

On the early to mid 90's, 6/8/9.9, what are the differences to increase/decrease the horsepower. This is referring to 2 stroke motors only

 

[racerone]

Carburetors.-----Jet size.-----Perhaps a restrictor plate as well.

 

[jimmbo]

Exhaust, Port Timing, Compression, are some of the other potential variances

 

[Scott Danforth]

the 9.9 is a bigger displacement than the 8hp since the 9.9 shares the block with the 15

 

[bbstacker1]

the 9.9 is a bigger displacement than the 8hp since the 9.9 shares the block with the 15

Later in the series the block was the same for the 9.9/15, the earlier ones, the 6/8/9.9 shared the same block with the 15 being different.

 

[Scott Danforth]

Later in the series the block was the same for the 9.9/15, the earlier ones, the 6/8/9.9 shared the same block with the 15 being different.

1985 and earlier 7.5 and 9.8 shared a same block. 1986 and later the 9.9 and 15 shared a block, the 18-30 shared a block and the 6-8hp shared a block.

 

[QBhoy]

As said. 6 and 8 are the same. 9.9 and 15 bigger and the same as each other. Significantly heavier that the 6/8 too.