differences-70hp/75hp-49er??

[formeone]

just got a "79 75hp motor wondering what the differences are between the 70 hp and 75hp,,,,, timeing, carbs ???...

[850cc racer]

I don't think timeing would make any difference? it'd be exhaust/ exhaust ports/ possibly carbs.

I found 2 blocks the other day, one a late 80's 60hp which I know it 60 as bought the complete motor, the other block on the top freeze plug had 75 in the code, only difference in them was exhaust ports and there was a massive difference I also have a genuine 75hp hustler I wanted to compare with the other 75..

850

[Powerabout]

The exhaust ports have a chamfer to fool it into thinking they are higher.
Bigger carbs
the 75 only came on a 15" therefore it had its own megaphone
They had a higer comp head available as on option

[Popa Sam]

The exhaust ports have a chamfer to fool it into thinking they are higher.
Bigger carbs
the 75 only came on a 15" therefore it had its own megaphone
They had a higer comp head available as on option

There were many 20" 75's built.

[MTECHMARINE]

Timed at 19 degrees BTDC, different carbs, the beveled ports and high compression head.

[Powerabout]

There were many 20" 75's built.

oops.. yes your right

[PIP]

15 inch motors were geared higher and bullet is about 3/4 narrower i think