70's 85 hp seems lazy

99_sierra

Cadet
Joined
Jun 7, 2009
Messages
7
ok i have a 70's 85 hp clean carbs new plugs etc...but it runs like a top but it seems like my 75 hp has more power then the 85 anyone have any sugestions plans out nice tried diferent props it had a 15 pitch so i put a 17 on and the 17 seems to work better just not gettin much top end speed
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: 70's 85 hp seems lazy

ok i have a 70's 85 hp clean carbs new plugs etc...but it runs like a top but it seems like my 75 hp has more power then the 85 anyone have any sugestions plans out nice tried diferent props it had a 15 pitch so i put a 17 on and the 17 seems to work better just not gettin much top end speed

Do you have a Tachometer? It's really hard to tell you anything unless we know if it's achieveing its max rated RPM's.
 

EazzeO

Cadet
Joined
Mar 31, 2010
Messages
27
Re: 70's 85 hp seems lazy

Hi
I seem toi be having the same problem with my 79 merc 80 hp. I'm also hitting 5200 rpms and I'm barly pushing 30 mph on a 14 foot that's not water logged.
Any help would be great.
Sorry I don't mean to steal your thread.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: 70's 85 hp seems lazy

Check the gear ratio as the 85 needs a 2.3.1 ratio. Sometimes people install a 2.1 unit and deprop it to offset the ratio, this makes it lazy on hole shot but runs ok at top end
 

99_sierra

Cadet
Joined
Jun 7, 2009
Messages
7
Re: 70's 85 hp seems lazy

ok maybe i'll try changing my whole lower unit because i have another lower unit off my 75 and it was great on top end
 
Top